992203_2002_NewTechnology

New Technology 2002 Design and Function Self-Study Program Course Number 992203 Audi of America, Inc. 3800 Hamlin Road Auburn Hills, MI 48326 Printed in U.S.A. February 2002 Audi of America, Inc. Service Training Printed in U.S.A. Printed 2/2002 Course Number 992203 ©2002 Audi of America, Inc. All rights reserved. All information contained in this manual is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights of Audi of America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, nor may these materials be modified or reposted to other sites without the prior expressed written permission of the publisher. All requests for permission to copy and redistribute information should be referred to Audi of America, Inc. Always check Technical Bulletins and the Audi Worldwide Repair Information System for information that may supersede any information included in this booklet. Trademarks: All brand names and product names used in this manual are trade names, service marks, trademarks, or registered trademarks; and are the property of their respective owners. i Table of Contents The Self-Study Program provides you with information regarding designs and functions. The Self-Study Program is not a Repair Manual. For maintenance and repair work, always refer to the current technical literature. Important/Note! New ! Introduction ................................................................................................... 1 Audi New Technology 2002 Engine Valve Train — Variable Valve Timing .............................................. 2 The Task of Variable Valve Timing, Operation of Variable Valve Timing, Intake Camshaft, Exhaust Camshaft, Oil System, Engine Management for Variable Valve Timing Engine Cooling — Electronically Controlled............................................. 16 Electronically Controlled Cooling System Overview, The Coolant Temperature Level, Coolant Thermostat Housing with Map Controlled Engine Cooling Thermostat F265, The Coolant Temperature Set Points, Engine Coolant Temperature (ECT) Sensor G62 and Engine Coolant Temperature (ECT) Sensor (On Radiator) G83, Map Controlled Engine Cooling Thermostat F265, Coolant Fan V7 and Coolant Fan -2- V177 Fuel Supply — 1.8T ..................................................................................... 25 Pressure-Regulated Fuel Filter Exhaust System — Exhaust Flap ............................................................... 26 Exhaust Flap — 3.0-Liter V6, Exhaust Flap Vacuum System Overview, Exhaust Flap Functional Diagram Suspension — Pneumatic Damping Control ............................................ 31 Pneumatic Damping Control Shock Absorbers Tires — Tire Pressure Monitoring .............................................................. 36 The Tire Pressure Monitoring System, System Components, System Functions, Tire Pressure Monitoring Functional Diagram Steering — Servotronic II ........................................................................... 66 Servotronic II Variable Effort Power Steering, Servotronic II System Overview Electrical System......................................................................................... 68 CAN Data Bus, Compass, Bi-Xenon Headlights, Audi Telematics by OnStar, Audi Digital Phone by Motorola, Symphony II Radio Transport Mode Knowledge Assessment ............................................................................. 81 Introduction 1 Audi New Technology 2002 In keeping with the Audi tradition of producing the best-engineered and most appealing cars in the world, Audi is introducing technical innovations and improvements in many vehicle systems for the 2002 model year. From performance and handling to convenience, comfort, and safety; from social responsibility to the sheer fun of driving; Audi continues to earn its reputation as a manufacturer of world- class cars with a technical edge. Some of the latest Audi technologies being introduced to the North American market for 2002 include: • Variable valve timing • Electronically controlled engine cooling • 1.8T engine fuel delivery modifications • Exhaust system noise reduction • Pneumatic damping control shock absorbers • Tire pressure monitoring • Servotronic II variable effort steering • CAN data bus • Electronic compass • Bi-xenon headlights • Audi Telematics by OnStar • Digital phone by Motorola • Symphony II radio transport mode This Self-Study Program describes the design and function of these technical innovations. SSP248/067 SSP222/035a SSP242/051 78500018 Engine Valve Train — Variable Valve Timing 2 The Task of Variable Valve Timing The valve timing illustrated here is intended to demonstrate the basic principle and the effects of variable valve timing. Each engine application has valve timing adapted to its own mechanics and engine management system. The quantity and appearance of components will vary from one application to another. Variable valve timing sets the most advantageous valve timing for the engine in each operating mode: idle, maximum power, and torque; as well as for exhaust gas recirculation. Idle At idle, the intake camshaft is set so that the intake valves open and close late. The exhaust camshaft is set so that exhaust valves close well before top dead center (TDC). Because there are only small amounts of residual gases from combustion, engine idle is smooth. Power To achieve good power at high engine speeds, the exhaust valves are opened late. This allows the expanding burning gases to act against the pistons longer. The intake valves open after top dead center and close well before bottom dead center (BDC). This enables the dynamic self-charging effect of the entering air, and increases power output. TDC BDC IC IO EO TDC EC IO IC BDC EO SSP246-001 SSP246-002 EC Intake IO Intake Opens Compression IC Intake Closes Power EO Exhaust Opens Exhaust EC Exhaust Closes Idle Power Engine Valve Train — Variable Valve Timing 3 Torque To achieve maximum torque, good volumetric efficiency is needed. This requires that the intake valves be opened early. Because the intake valves open early, they close early as well. This keeps the fresh gases from being pushed back out the intake valve port. The exhaust camshaft closes the exhaust valves just before top dead center. Exhaust Gas Recirculation Internal exhaust gas recirculation can be achieved by adjusting the intake and exhaust camshafts for a period of valve overlap, when both the intake and exhaust valves are open. The amount of overlap determines the amount of recirculated exhaust gas. The intake camshaft is set so that it opens the intake valves well before top dead center. The exhaust camshaft does not close the exhaust valves until just before top dead center. As a result, both valves are open and some of the exhaust gas is recirculated in the cylinder for reburning during the next power stroke. The advantage of internal exhaust gas recirculation over external exhaust gas recirculation is the fast reaction of the system and very even distribution of the recirculated exhaust gases. TDC EC BDC EO IC IO SSP246-003 TDC EC IO IC BDC EO SSP246-004 Intake IO Intake Opens Compression IC Intake Closes Power EO Exhaust Opens Exhaust EC Exhaust Closes Torque Exhaust Gas Recirculation Engine Valve Train — Variable Valve Timing 4 Operation of Variable Valve Timing The Motronic Engine Control Module J220 controls the variable valve timing. To do this, it requires information from various sensors about engine speed, engine load and temperature, and the positions of the crankshaft and the camshafts. To adjust the camshafts on the cylinder bank shown, the Motronic Engine Control Module J220 actuates Valve 1 for Camshaft Adjustment N205 and Camshaft Adjustment Valve 1 (Exhaust) N318. They in turn open oil galleries in the control housing. Engine oil flows through the control housing and camshafts into the camshaft adjusters. The inner rotors (pivot motor rotors) rotate and adjust the intake and exhaust camshaft positions in accordance with the specifications programmed into the Motronic Engine Control Module J220. SSP246-012 Camshaft Position (CMP) Sensor G40 Camshaft Position (CMP) Sensor 2 G163 Intake Camshaft Exhaust Camshaft Valve 1 for Camshaft Adjustment N205 Camshaft Adjustment Valve 1 (Exhaust) N318 Oil Pump Engine Speed Air Mass and Air Temperature (Engine Load) Coolant Temperature Motronic Engine Control Module J220 One cyllinder bank of W12 engine shown. Engine Valve Train — Variable Valve Timing 5 Intake Camshaft Intake Camshaft Adjustment Each intake camshaft is regulated by the Motronic Engine Control Module J220 over the entire speed range of the engine. The maximum amount of adjustment possible is through 52 degrees of crankshaft angle. Adjustment is determined by a control map stored in the Motronic Engine Control Module J220. As used here, map refers to an electronic database that sets up the relationship between incoming sensor information and outgoing control signals. Maps are also referred to as “look-up tables.” Intake Camshaft Adjuster Design The adjusting mechanism of each intake camshaft adjuster consists of: • A combined housing and outer rotor connected directly to the timing chain or belt. • An inner rotor (pivot motor rotor) attached to the end of the camshaft. The adjusters are locked mechanically until the necessary engine oil pressure has built up. Using a mechanical detent device, a spring- loaded differential pressure pin prevents the camshaft from being adjusted during the engine start cycle. The adjuster is designed to move to the retard position and remain locked there whenever the engine is turned off. The rising engine oil pressure unlocks the spring-loaded differential pressure pins. Outer Rotor Inner Rotor (Pivot Motor Rotor) Oil Galleries SSP246-155 Intake Camshaft Adjuster Camshaft Adjuster Inner Rotor with Connection to Camshaft SSP255/021 Mechanical Detent Engine Valve Train — Variable Valve Timing 6 How the Intake Camshaft is Advanced For exhaust gas recirculation and increasing torque, each intake camshaft must be set so that the intake valves open well before top dead center. To advance valve timing on the cylinder bank shown, the Motronic Engine Control Module J220 actuates Valve 1 for Camshaft Adjustment N205 which adjusts the position of the control piston in the control housing. The control housing oil gallery for timing advance is opened up in accordance with the new position of the control piston. With the oil gallery opened, engine oil under pressure flows through the control housing and into the forward ring channel in the intake camshaft. From there the pressurized oil flows through five passages drilled through to the front face of the camshaft and into the five advance chambers of the camshaft adjuster, where it presses against the vanes of the inner and outer rotors. This causes the inner rotor (pivot motor rotor) to rotate to an advanced position within the outer rotor. Since the camshaft is fixed to the inner rotor (pivot motor rotor) and the crankshaft is mechanically linked to the outer rotor, this effectively rotates the intake camshaft in the direction of crankshaft rotation and the intake valves open sooner. If the variable valve timing function fails, the camshaft adjuster will be set by engine oil pressure to the basic retarded position. Engine Oil Pressure Oil Return Oil Return Control Piston Valve 1 for Camshaft Adjustment N205 Front Drilled Passage Ring Channels Control Housing Timing Advance Oil Gallery SSP246-150 Inner Rotor (Pivot Motor Rotor) One cylinder bank shown. Engine Valve Train — Variable Valve Timing 7 How the Intake Camshaft is Retarded When the engine is idling or when a lot of power is required from the engine, each intake camshaft is rotated so that the intake valves open late — after top dead center. To retard the intake camshaft on the cylinder bank shown, the Motronic Engine Control Module J220 actuates Valve 1 for Camshaft Adjustment N205, which opens the gallery for timing retardation by moving the control piston. Engine oil under pressure flows through the control housing into the rearward ring channel of the camshaft. From there the pressurized oil flows through drilled passages in the camshaft to the pocket hole of the securing bolt for the camshaft adjuster. The pressurized oil then flows through five drilled passages in the camshaft adjuster and into the oil chamber for timing retardation where it presses against the vanes of the inner and outer rotors. This causes the inner rotor (pivot motor rotor) to rotate to a retarded position within the outer rotor. This movement effectively rotates the intake camshaft in the opposite direction from crankshaft rotation and the intake valves open later. At the same time that the oil gallery for timing retardation is opened, the control piston opens the oil return for the gallery for timing advance, relieving the pressure there. The rotation of the inner rotor (pivot motor rotor) in the retard direction pushes the oil out of the timing advance chamber through the timing advance oil gallery. Engine Oil Pressure Oil Return Control Piston Oil Return Timing Retardation Oil Gallery Pocket Hole for Securing Bolt Control Housing Ring Channels Front Drilled Passage Inner Rotor (Pivot Motor Rotor) Valve 1 for Camshaft Adjustment N205 SSP246-151 One cylinder bank shown. Engine Valve Train — Variable Valve Timing 8 How Regulation Works Regulation enables continuous variation of the position of each intake camshaft between advanced and retarded through a maximum adjustment range of 52 degrees of crankshaft angle. On the cylinder bank shown, the Camshaft Position (CMP) Sensor G40 provides a signal to the Motronic Engine Control Module J220 which allows it to monitor the exact position of the intake camshaft at any given moment. The control map in the Motronic Engine Control Module J220 determines the intake camshaft adjustment using this camshaft position information as well as engine load, speed, and coolant temperature readings. When the control map calls for advanced timing, the Motronic Engine Control Module J220 activates the Valve 1 for Camshaft Adjustment N205, which moves the control piston in the advance timing direction. Pressurized oil is diverted through the control housing and drilled passages in the camshaft into the camshaft adjuster and moves the camshaft into an advanced position. Moving the control piston in the advanced direction simultaneously opens the oil return through the oil channel for retarding timing. When the desired angle of adjustment is attained, the control map initiates movement of the control piston to a position that maintains equal pressure in both camshaft adjuster chambers to maintain the adjustment angle. To move the camshaft in the retard timing direction, the regulation process is similar but pressurized oil flow is reversed. Valve 1 for Camshaft Adjustment N205 SSP246-150a Pressure to Advance Timing Equalized Pressure to Maintain Adjustment Valve 1 for Camshaft Adjustment N205 SSP246-152One cylinder bank shown. Engine Valve Train — Variable Valve Timing 9 Exhaust Camshaft Exhaust Camshaft Adjustment In contrast to the intake camshaft adjustment which is continuously variable over the entire range of 52 degrees of crankshaft angle, the adjustment of each exhaust camshaft is essentially “on” or “off” to advance the exhaust camshaft timing or return it to normal. The adjustment variation between these two positions is 22 degrees of crankshaft angle. Outer Rotor Oil Galleries Wider Vanes Inner Rotor (Pivot Motor Rotor) SSP246-156 Exhaust Camshaft Adjuster Exhaust Camshaft Adjuster Design The adjusting mechanism of the exhaust camshaft adjuster is nearly identical to the design of the intake camshaft adjuster: • A combined housing and outer rotor connected directly to the timing chain or belt. • An inner rotor (pivot motor rotor) attached to the end of the camshaft. • The vanes of the inner rotor (pivot motor rotor) are wider to limit adjustment travel to the smaller 22 degrees of crankshaft angle required of the exhaust camshaft. Engine Valve Train — Variable Valve Timing 10 Exhaust Camshaft Normal Position Each exhaust camshaft is in its normal position when the engine is being started and at engine speeds above idle. In the normal position, the exhaust valves close just before top dead center. Each exhaust camshaft is in the normal position in the engine operating modes for maximum power and torque; as well as for exhaust gas recirculation. Under these conditions, on the cylinder bank shown the Camshaft Adjustment Valve 1 (Exhaust) N318 is not actuated. How the Normal Position Works In the normal position, the exhaust camshaft is positioned so that the exhaust valves close shortly before top dead center. The Camshaft Adjustment Valve 1 (Exhaust) N318 on the cylinder bank shown is not actuated by the Motronic Engine Control Module J220. In the normal position, the oil gallery for timing retardation is open. Through this oil gallery, engine oil under pressure reaches the rearward ring channel in the exhaust camshaft. From there the pressurized oil flows through drilled passages in the camshaft to the pocket hole of the securing bolt for the camshaft adjuster. The pressurized oil then flows through five drilled passages in the camshaft adjuster and into the oil chamber for normal position where it presses against the vanes of the inner and outer rotors. This causes the inner rotor (pivot motor rotor) to rotate to the stops at the normal position within the outer rotor, rotating the camshaft along with it. The exhaust camshaft on the cylinder bank shown remains in this position as long as the Camshaft Adjustment Valve 1 (Exhaust) N318 solenoid is not actuated. At the same time that the oil gallery for timing retardation pressure is open, the oil return for the gallery for timing advance is open, relieving the pressure there. The rotation of the inner rotor (pivot motor rotor) in the retard direction pushes the oil out of the timing advance chamber through the oil gallery for timing advance. Engine Valve Train — Variable Valve Timing 11 Inner Rotor (Pivot Motor Rotor) Outer Rotor Camshaft Adjustment Valve 1 (Exhaust) N318 Control Piston Oil Return Engine Oil Pressure Oil Return Oil Gallery for Timing Retardation Pocket Hole for Securing Bolt Oil Gallery for Timing Advance Control Housing Ring Channel Front Drilled Passage SSP246-157 One cylinder bank shown. Exhaust Camshaft Advanced Position Each exhaust camshaft is set to the advanced position at engine speeds from idle to about 1,200 rpm. How the Exhaust Camshaft is Advanced To advance exhaust valve timing on the cylinder bank shown, the Motronic Engine Control Module J220 actuates the Camshaft Adjustment Valve 1 (Exhaust) N318, which adjusts the position of the control piston in the control housing. The control housing oil gallery for timing advance is opened up in accordance with the new position of the control piston. With the oil gallery opened, engine oil under pressure flows through the control housing and into the forward ring channel in the exhaust camshaft. From there the pressurized oil flows through five passages drilled through to the front face of the camshaft and into the five advance chambers of the camshaft adjuster, where it presses against the vanes of the inner and outer rotors. This causes the inner rotor (pivot motor rotor) to rotate to an advanced position within the outer rotor. Since the camshaft is fixed to the inner rotor (pivot motor rotor) and the crankshaft is mechanically linked to the outer rotor, this effectively rotates the intake camshaft in the direction of crankshaft rotation and the exhaust valves open and close earlier. At the same time that the oil gallery for timing advance pressure is open, the oil return for the gallery for timing retardation is open, relieving the pressure there. The rotation of the inner rotor (pivot motor rotor) in the advance direction pushes the oil out of the timing retard chamber through the oil gallery for timing retardation. If the variable valve timing function fails, the exhaust camshaft adjuster will remain in the normal position, the exhaust valves close just before top dead center. Oil System The variable valve timing system operates at an oil pressure of 10.2 psi (70 kPa) and above. Oil flow through the exhaust and intake camshafts is virtually identical. Engine Valve Train — Variable Valve Timing 12 Engine Valve Train — Variable Valve Timing 13 Control Piston Oil ReturnEngine Oil Pressure Oil Return Oil Gallery for Timing Retardation Oil Gallery for Timing Advance Pocket Hole for Securing Bolt Control Housing Ring Channels Front Drilled Passage Inner Rotor (Pivot Motor Rotor) Outer Rotor Camshaft Adjustment Valve 1 (Exhaust) N318 SSP246-156a One cylinder bank shown. Engine Management for Variable Valve Timing Typical System Overview for V6 Engines Motronic Engine Control Module J220 Valve 1 for Camshaft Adjustment N205 Camshaft Adjustment Valve 1 (Exhaust) N318 Data Link Connector (DLC) Wire Connector TV14 Camshaft Position (CMP) Sensor G40 Camshaft Position (CMP) Sensor 2 G163 Engine Speed (RPM) Sensor G28 Mass Air Flow (MAF) Sensor G70 (In Some Applications Combined with Intake Air Temperature (IAT) Sensor G42) Engine Coolant Temperature (ECT) Sensor G62 SSP246-029 Engine Valve Train — Variable Valve Timing 14 Camshaft Position (CMP) Sensor 3 G300 Camshaft Position (CMP) Sensor 4 G301 Valve 2 for Camshaft Adjustment N208 Camshaft Adjustment Valve 2 (Exhaust) N319 Engine Valve Train — Variable Valve Timing 15 Learning Ability of the System The entire variable valve timing system is adaptive. This adaptability compensates for component and assembly tolerances and wear. The Motronic Engine Control Module J220 initiates adaptation when the engine is idling and the coolant temperature is greater than 140°F (60°C). During adaptation, the Motronic Engine Control Module J220 uses signals from the Engine Speed (RPM) Sensor G28, the Camshaft Position (CMP) Sensor G40, the Camshaft Position (CMP) Sensor 2 G163, the Camshaft Position (CMP) Sensor 3 G300, and the Camshaft Position (CMP) Sensor 4 G301, to check the idle settings for the intake and exhaust camshafts. If the actual value does not agree with the control map specification stored in the Motronic Engine Control Module J220, the camshaft positions are adjusted to match the specification. Adaptation Value Actual Value Specification TDC BDC SSP246-009 Electronically Controlled Cooling System Overview The aim of developing an electronically controlled cooling system was to be able to set the operating temperature of the engine to a specified value based on the load state. An optimal operating temperature is set according to “maps” stored in the Motronic Engine Control Module J220 by heating the thermostat electrically and adjusting the radiator fan settings. Cooling can thus be adapted to the engine’s overall performance and load state. As used here, map refers to an electronic database that sets up the relationship between incoming sensor information and outgoing control signals. Maps are also referred to as “look-up tables.” Advantages The advantages of adapting the coolant temperature to the current operating state of the engine are: • Lower fuel consumption in the part- throttle range. • Reduced raw CO and HC emissions. Changes to the conventional cooling circuit include: • Integration in the cooling circuit through minimal design modifications. • The coolant distributor housing and thermostat are combined to form a single module. • There is no longer any need for a coolant thermostat on the cylinder head. • Motronic Engine Control Module J220 contains the maps of the electronically controlled cooling system. Electronically controlled cooling is only used on the 1.8T AMB engine at the time of printing. Other engines will be added in the future. 16 Engine Cooling — Electronically Controlled Engine Cooling — Electronically Controlled 17 The Coolant Temperature Level Engine performance is dependent on proper engine cooling. In the electronically controlled cooling system, the coolant temperatures range from 203°F to 230°F (95°C to 110°C) in the part-throttle range and from 185°F to 203°F (85°C to 95°C) in the full-throttle range. Engine load and cooling should always be considered together. En gi ne L oa d Engine Speed Part-Throttle Range 203°F to 230°F (95°C to 110°C) Full-Throttle Range 185°F to 203°F (85°C to 95°C) SSP222-013 Coolant Temperature Level as a Function of Engine Load with Mapped Cooling • Higher temperatures in the part-throttle range improve efficiency, which in turn reduces fuel consumption and pollutants in the exhaust gases. • Lower temperatures in the full-throttle range increase power output. The inducted air is heated to a lesser degree, boosting performance. Engine Cooling — Electronically Controlled 18 Coolant Thermostat Housing with Map Controlled Engine Cooling Thermostat F265 The Functional Components • An expansion-element thermostat with a wax thermocouple (Map Controlled Engine Cooling Thermostat F265). • Resistance heating in the wax thermocouple. • Pressure springs for mechanically closing the coolant ducts. • One large valve disc and one small valve disc. Function The Map Controlled Engine Cooling Thermostat F265 in the coolant distributor housing is always immersed in coolant. The wax thermocouple regulates the thermostat opening temperature unheated as before, but is rated for a different opening temperature. The coolant temperature causes the wax to liquefy and expand, producing a lifting movement of the lifting pin. This normally happens in accordance with the new coolant temperature profile of 230°F (110°C) at the engine cylinder head outlet, without the application of voltage to the heating resistor integrated into the wax thermocouple. When voltage is applied to the heating resistor, it heats the wax thermocouple above the temperature of the surrounding coolant. The adjustment of the lifting pin stroke is then determined not only by the coolant temperature, but also as specified by the map stored in the Motronic Engine Control Module J220. Lifting Pin Map Controlled Engine Cooling Thermostat F265 Small Valve Disc for Closing the Small Coolant Circuit Pressure Spring Electrical Connection for Heating Thermostat Large Valve Disc for Closing the Large Coolant Circuit Heating Resistor SSP222-035 Engine Cooling — Electronically Controlled 19 The Coolant Temperature Set Points Activation of the Map Controlled Engine Cooling Thermostat F265 is regulated by maps to distribute the coolant flow volume between the large and small cooling circuits. The relevant temperature set points are stored in these maps. The pre-control pulse duty factor information is stored in a map. This map is required to determine the coolant temperature set point when the vehicle is at rest with the engine running. The information required for this purpose is obtained by comparing the actual temperature and the specified temperature as factors of engine speed. A temperature constant between 185°F and 230°F (85°C and 110°C) can then be set for the Map Controlled Engine Cooling Thermostat F265 based on engine speed and coolant temperature. In the specified coolant temperature 1 map the temperature setting is calculated from the engine load (determined by measured intake air mass) and engine speed. The specified coolant temperature 2 setting is calculated from temperature set points that are stored based on road speed and intake air temperature in a second map. By comparing maps 1 and 2, the lower value is used by the Motronic Engine Control Module J220 as the set point and the Map Controlled Engine Cooling Thermostat F265 is set accordingly. The Map Controlled Engine Cooling Thermostat F265 is not activated until a temperature threshold has been exceeded and the coolant temperature is just below the set point. Specified Temperature Engine Speed P re -C on tr ol P ul se D ut y Fa ct or SSP222-018 Map — Pre-Control Pulse Duty Factor N om in al T em pe ra tu re Engine Load (Intake Air Mass)194°F (90°C) Engine Speed SSP222-016 SSP222-017 Road Speed 185°F (85°C) N om in al T em pe ra tu re Intake Air Temperature Map — Specified Coolant Temperature 1 Map — Specified Coolant Temperature 2 Engine Cooling — Electronically Controlled 20 Engine Coolant Temperature (ECT) Sensor G62 and Engine Coolant Temperature (ECT) Sensor (On Radiator) G83 These sensors both operate as negative temperature coefficient (NTC) sensors. The coolant temperature set points are stored in the Motronic Engine Control Module J220 in the form of maps. The actual coolant temperature values are registered at two different points in the cooling circuit and indicated to the Motronic Engine Control Module J220 in the form of a voltage signal. • Coolant actual value 1 is measured at the cylinder head coolant outlet by Engine Coolant Temperature (ECT) Sensor G62 located in the upper level of the coolant distributor housing. • Coolant actual value 2 is measured at the radiator by Engine Coolant Temperature (ECT) Sensor (On Radiator) G83 before the radiator coolant outlet. SSP222-023 SSP222-003 SSP222-024 Engine Coolant Temperature (ECT) Sensor G62 (At engine outlet — determines coolant actual value 1) Engine Coolant Temperature Sensor (On Radiator) G83 (At radiator outlet — determines coolant actual value 2) Coolant circuit shown is for example only. G62 G83 J220 SSP222-030 Signal Utilization Comparison of the specified temperatures stored in the maps with the coolant actual value 1 temperature gives the pulse-width- modulated signal for the application of voltage to the heating resistor in the Map Controlled Engine Cooling Thermostat F265. Comparison of the coolant actual values 1 and 2 is the basis for activation of the electric Coolant Fan V7 and Coolant Fan -2- V177. Effects of Failure If Engine Coolant Temperature (ECT) Sensor G62 fails, a defined substitute value of 203°F (95°C) is used for coolant temperature control and the first fan speed stays activated. If Engine Coolant Temperature (ECT) Sensor (On Radiator) G83 fails, the control function remains active and the first fan speed stays activated. If a certain temperature threshold is exceeded, the second fan speed is activated. If both sensors fail, maximum voltage is applied to the heating resistor in the Map Controlled Engine Cooling Thermostat F265 and the second fan speed stays activated. Engine Cooling — Electronically Controlled 21 Map Controlled Engine Cooling Thermostat F265 The Map Controlled Engine Cooling Thermostat F265 is the coolant control actuator. A standard expansion-element thermostat without the benefit of electric heating is designed to regulate engine outlet coolant at a specific temperature. The Map Controlled Engine Cooling Thermostat F265 sets the coolant temperature at a design- defined point in much the same way, but the defined set point can be changed to meet the cooling needs of the engine using the available control maps. A heating resistor is integrated into the wax thermocouple expansion element of the Map Controlled Engine Cooling Thermostat F265. Without the application of voltage to the heating resistor, the surrounding coolant temperature causes the wax in the expansion element to liquefy and expand at 230°F (110°C). With an application of voltage, the heating resistor heats the wax above the temperature of the surrounding coolant. The heating wax expands causing the lifting pin to extend in accordance with the map (stroke “X” in the illustration). The positions of the coolant thermostat large and small valve discs are mechanically adjusted by the movement of the lifting pin. The purpose of the thermostat heating system is not to heat the coolant. It heats the expansion element in a controlled manner in order to open the large cooling circuit. x Wax Thermocouple Lifting Pin Heating Resistor SSP222-006 Map Controlled Engine Cooling Thermostat F265 Engine Cooling — Electronically Controlled 22 Engine Cooling — Electronically Controlled 23 Thermostat heating resistor heating is controlled by the Motronic Engine Control Module J220 in accordance with the map by a pulse-width-modulated (PWM) signal. The extent of heating varies depending on pulse width and time. No voltage is applied when the vehicle is at rest with the engine idling or during the engine starting cycle. Rule: • PWM low (without voltage) = high coolant temperature • PWM high (with voltage) = low coolant temperature Effects of Failure If there is no operating voltage present: • Thermostat control takes place only by means of the wax thermocouple expansion element. • The first fan speed is continuously activated. J220 Motronic Engine Control Module J293 Coolant Fan Control Module V7 Coolant Fan V177 Coolant Fan -2- J293 3131 V7 M V177 M J220 SSP222-025 Engine Cooling — Electronically Controlled 24 Coolant Fan V7 and Coolant Fan -2- V177 The full-throttle low coolant temperature mode makes heavy demands on the cooling system. To increase its cooling capacity, the Motronic Engine Control Module J220 can initiate one of two speed settings for Coolant Fan V7 and Coolant Fan -2- V177. Fan control is based on the difference between the coolant temperatures measured at the engine outlet and at the radiator outlet. The Motronic Engine Control Module J220 stores the control conditions for the fans in two maps: • Temperature difference for fan, first speed. • Temperature difference for fan, second speed. Both maps are similar to the one shown here, and both are dependent on engine load (intake air mass) and engine speed (rpm). There are three fan operating modes: • Off. • On, first speed. • On, second speed. Run-On Run-on of Coolant Fan V7 and Coolant Fan -2- V177 after the engine is turned off is time and temperature dependent. Effects of Failure If a fault occurs in the circuit for the first fan output stage, the second stage is activated. If a fault occurs in the circuit for second fan output stage, the Map Controlled Engine Cooling Thermostat F265 is fully energized as a safety precaution. SSP222-026 Engine Load (Intake Air Mass) Te m pe ra tu re D iff er en ce Engine Speed Map 1 — Temperature Difference for Fan First Speed Electrical Circuit Compenents 25 Fuel Supply — 1.8T Pressure-Regulated Fuel Filter For the 1.8T engine, the fuel supply is routed through a pressure-regulated filter. This new design eliminates the need for a fuel return line from the engine fuel rail. Fuel in the tank is pressurized by the in-tank fuel pump and supplied through port “VL” to the filter. The pressurized fuel fills the chamber, flowing through the paper filter element and out through the port labeled “MOTOR” to supply the engine fuel rail. If the fuel pressure in the filter exceeds the filter pressure regulator threshold, the regulator valve opens and routes fuel through the plastic center tube and out at port “RL” to return to the tank. Fuel filter port “E” vents the pressure regulator to atmospheric pressure through the evaporative emission (EVAP) canister. When the pressure-regulated fuel filter is installed, the arrows printed on the filter must point in the direction of fuel flow. 78500005 Evaporative Emission (EVAP) Canister Pressure Regulator Filter Pressure Regulator Vent to EVAP Canister Port E Engine Fuel Supply to Engine Port MOTOR Fuel Filter Tank Vent to EVAP Canister Port RL Fuel Return to Tank Port VL Fuel Supply from Tank Fuel Tank Exhaust Flap — 3.0-Liter V6 Front-wheel drive vehicles equipped with 3.0L V6 engines have an exhaust flap installed at one of the rear silencer outlets. This design ensures that legal restrictions on noise are met at engine idle and low engine speeds. 78500006 Cross Section A 78500007 A Exhaust Flap 26 Exhaust System — Exhaust Flap Exhaust System — Exhaust Flap 27 Exhaust Flap Operation Exhaust flap operation is controlled by the Motronic Engine Control Module J220. When vehicle speed is above 3.1 mph (5 km/h) and engine speed is above 2000 rpm, there is no signal to the Valve for Exhaust Flap N220 and the flap is open to allow maximum flow of exhaust gases. When vehicle speed is below 3.1 mph (5 km/h) or the engine speed drops below 1800 rpm, the Motronic Engine Control Module J220 sends a signal to activate the Valve for Exhaust Flap N220 and the flap is closed to reduce exhaust noise to an acceptable level. Effect of Failure In the event of exhaust flap system failure, the default position is with the flap open. Open Closed 6500 6000 5500 5000 4500 4000 3500 3000 2500 2000 1500 1000 500 0 0 50 100 150 200 250 km/h 0 31 62 93 124 155 mph Vehicle Speed E n g in e S p ee d ( R P M ) 3.1 mph (5 km/h) Acceleration Deceleration 78500008 3.0 V6 220 hp (162 kW) Switching Diagram of the Exhaust Flap 78500009 Atmospheric Pressure Vacuum The system applies vacuum and the flap is closed. Motronic Engine Control Module J220 Valve for Exhaust Flap N220 Vacuum Check Valve Intake Manifold Flap is open. Other Consumers Vacuum Reservoir Exhaust Flap Open Other Consumers Exhaust Flap Closed Valve for Exhaust Flap N220 Motronic Engine Control Module J220 Vacuum Check Valve Intake Manifold Vacuum Reservoir Exhaust System — Exhaust Flap 28 Exhaust System — Exhaust Flap 29 Exhaust Flap Vacuum System Overview 78500010 Vacuum Unit for Intake Manifold Change-Over Change-Over Valve for Intake Manifold Flap N239 Valve for Exhaust Flap N220 Secondary Air Injection (AIR) Solenoid Valve N112 Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 Diagnostics Pump for Fuel System Exhaust Flap Combination Valve for Secondary Air Injection Brake Booster Suction Jet Pump Vacuum Check Valve Evaporative Emission (EVAP) Charcoal Canister Fuel Distribution Rail with Pressure Control Valve Vacuum Reservoir Vacuum Reservoir Combination Valve for Secondary Air Injection Exhaust Flap Functional Diagram Components G6 Fuel Pump G21 Speedometer G22 Speedometer Vehicle Speed Sensor (VSS) G28 Engine Speed (RPM) Sensor G186 Throttle Drive (Power Accelerator Actuation) G187 Angle Sensor 1 for Throttle Drive G188 Angle Sensor 2 for Throttle Drive S34 15A J271 S28 20A 96 M N220 15 31 30 CAN-H CAN-L G188G187G186 +- J338 M J220 G28 J218 G21 G22 In Out S7 10A J218 Instrument Cluster Combination Processor J220 Motronic Engine Control Module J271 Motronic Engine Control Module Power Supply Relay N220 Valve for Exhaust Flap S7 Fuse S28 Fog Light Fuse S34 Terminal 50 Fuse 78500011 Exhaust System — Exhaust Flap 30 Suspension — Pneumatic Damping Control 31 Pneumatic Damping Control Shock Absorbers Rear Axle Variable Load Recognition System The Audi allroad quattro four-level air suspension employs a continuously variable load recognition system at the rear axle. This system enhances vehicle handling by maintaining suspension damping at a constant level whether the vehicle is partially or fully loaded. The use of air springs in combination with the natural vibration frequency of the body structure maintains virtually constant vibration characteristics regardless of the load on the system. The system adjusts to provide a comfortable ride with a light load and sufficiently firm damping under a heavy load. The pneumatic damping control (PDC) shock absorbers provide this capability. In PDC shock absorbers, the damping force is varied as a direct result of the amount of air pressure present in the air springs at any given moment. SSP242/043 Hose Coaxial Arrangement of Air Spring and PDC Shock Absorber SSP242/057 1.0 1.2 1.4 Body Weight Ratio D eg re e of D am pi ng PDC Shock Absorbers Conventional Shock Absorers 1.6 1.8 2.0 Air Spring PDC Valve The damping force is altered by a PDC valve integrated into the shock absorber. The PDC valve is connected to air spring air chamber pressure by a pneumatic hose. A variable throttle valve in the PDC valve is controlled by the internal air pressure in the air spring. This provides a continuously variable control of damping in direct proportion to the load on the suspension system. The movement of the throttle valve changes the resistance to hydraulic fluid flow in the shock absorber and thus the damping force during both compression and rebound. The air connector in the PDC valve includes a restricting orifice between the air spring side and the valve piston side. This air restriction reduces the influence of the dynamic pressure changes in the air spring on the shock absorber during compression and rebound. SSP242/042 SSP242/087 Separate Arrangement of Air Spring and PDC Shock Absorber 0 0 0.43 0.85 1.28 1.71 2.13 2.56 2.99 3.41 ft/s 0 0.13 0.26 0.39 0.52 0.65 0.78 0.91 1.04 m/s 0 200 400 600 800 1000 1200 1400 1600 45 90 135 180 225 270 315 360 Nlb Piston Speed Compression Rebound D am pi ng F or ce 138 psi (950 kPa) 116 psi (800 kPa) 94 psi (650 kPa) Air Spring Hose PDC Valve Suspension — Pneumatic Damping Control 32 Suspension — Pneumatic Damping Control 33 Design and Function The PDC valve affects the resistance to hydraulic fluid flow in the working cylinder on the piston rod side. The hydraulic fluid in the piston rod side of the working cylinder is routed to the PDC valve through holes in the side of the cylinder near the top and a jacket that encases the cylinder. The flow resistance of the PDC valve is directly proportional to the air spring air pressure. The PDC valve has a low flow resistance when the air spring air pressure is relatively low; when the vehicle is lightly loaded. Some of the hydraulic fluid gets past the PDC valve throttle valve, effectively reducing the damping force in the shock absorber. The total damping force in the shock absorber for compression or rebound damping is determined by the flow resistance of the piston valve, the bottom valve, and the PDC valve. SSP242/033 Working Cylinder Piston Valve with Sealing Collar Holes Gas Charge Bottom Valve Throttle Valve PDC Valve Restricting Orifice in Air Connector Piston Rod Side of Working Cylinder Rebound Stop Cylinder Jacket Function during compression at low air spring air pressure During compression, the piston is pushed downward in the shock absorber working cylinder. Some of the hydraulic fluid flow is through the piston valve. Most of the fluid flows through the bottom valve, with a proportional amount flowing through the open PDC valve, the cylinder jacket, and through the holes in the side of the cylinder into the cylinder behind the moving piston. Since the air spring air pressure is low, the flow resistance at the PDC valve is low. More fluid can get past the PDC valve and the damping force is reduced. Function during compression at high air spring pressure Since the controlling air spring air pressure is high, the flow resistance at the PDC valve is high. Depending upon the control pressure, little or no fluid gets past the PDC valve. Most of the fluid must flow through the piston valve, and the damping force is increased. Low Air Spring Air Pressure PDC Valve Closed SSP242/069 SSP242/070 PDC Valve Open High Air Spring Air Pressure 34 Suspension — Pneumatic Damping Control 35 Suspension — Pneumatic Damping Control Low Air Spring Air Pressure SSP242/051 High Air Spring Air Pressure SSP242/052 PDC Valve Open PDC Valve Closed Function during rebound at low air spring air pressure During rebound, the piston is drawn upward. Part of the fluid flows through the piston valve, some flows through the bottom valve, and the rest flows through the holes in the side of the cylinder and through the cylinder jacket to the PDC valve. Since the air spring air pressure is low, the flow resistance at the PDC valve is low. More fluid can get past the PDC valve and the damping force is reduced. Function during rebound at high air spring air pressure Since the air spring air pressure is high, the flow resistance at the PDC valve is high. Depending upon the control pressure, little or no fluid gets past the PDC valve. Most of the fluid must flow through the piston valve, and the damping force is increased. The Tire Pressure Monitoring System The tire pressure monitoring system used by Audi is a four-wheel system. Although the spare wheel is monitored and “managed” by the Tire Pressure Monitoring Control Module J502, it is excluded from the system status messages. (For further details, refer to Spare Wheel.) Data transfer from the sensors at each wheel to the Tire Pressure Monitoring Control Module J502 is by radio-frequency (RF) transmission. Information exchange between the peripheral components in the vehicle takes place via the convenience CAN data bus. A measuring and transmitter module mounted on the tire valve sends a radio signal at regular time intervals to the antenna for tire pressure monitoring integrated in the wheel housing. This signal is then relayed to the Tire Pressure Monitoring Control Module J502. The Tire Pressure Monitoring Control Module J502 evaluates the tire pressures and any pressure changes and sends corresponding system status messages to the Instrument Cluster Combination Processor J218. These messages are indicated to the driver on the display of the Driver Information System (DIS). The tire pressure monitoring system offers the following advantages: • Increased safety through early “low tire pressure” warnings. • More convenience through the elimination of regular tire pressure monitoring. The tire pressure need only be corrected when this is indicated. SSP219/012 • Longer service life of tires. A pressure deficit of 4.4 psi (30 kPa) can reduce the service life of tires by up to 25%. • Lower fuel consumption through correct tire pressure. 36 Tires — Tire Pressure Monitoring Tire pressure monitoring differentiates between the following situations: • Slow loss of pressure. • Sudden loss of pressure. • Flat tire when the vehicle is stationary. A slow loss of pressure is indicated to the driver at an early stage so the driver can check the tires or correct the tire pressure. If a sudden loss of pressure occurs (blowout, flat tire) while travelling, the driver is alerted immediately. The driver will normally notice this anyway by the way the vehicle reacts. The tire pressure monitoring system indicates the loss of pressure to the driver at an early stage so that he or she can take appropriate action. The system indicates a flat tire when the vehicle is stationary to the driver directly after turning on the ignition. 37 Tires — Tire Pressure Monitoring System Components Vehicle Overview The tire pressure monitoring system includes the following components: • Five tire pressure sensors • Four Antennas for Tire Pressure Check Sensor for Tire Pressure, Rear Right G225 MENUE RETURN INFO Antenna for Tire Pressure Check, Rear Right R62 Function Selector Switch II E272 Instrument Cluster Combination Processor J218 Tire Pressure Monitoring Control Module J502 Sensor for Tire Pressure, Front Right G223 SSP219/026 Antenna for Tire Pressure Check, Front Right R60 Sensor for Tire Pressure, Spare Tire G226 Antenna for Tire Pressure Check, Rear Left R61 Sensor for Tire Pressure, Rear Left G224 Antenna for Tire Pressure Check, Front Left R59 Sensor for Tire Pressure, Front Left G222 • Tire Pressure Monitoring Control Module J502 • Instrument Cluster Combination Processor J218 • Function Selector Switch II E272 Metal Tire Inflation Valves The tire inflation valves have been redesigned for use with the tire pressure monitoring system. Metal valves are now used in place of the rubber valves used previously. Metal valve bodies are reusable. When installing a new tire on a used rim, only the valve insert need be replaced (refer to Repair Manual). 38 Tires — Tire Pressure Monitoring SSP219/030 Metal Valve Body Sealing Ring Valve InsertPlain Washer Cap Nut Cap SSP219/008 39 Tires — Tire Pressure Monitoring Sensors for Tire Pressure: Front Left G222 Front Right G223 Rear Left G224 Rear Right G225 Spare Tire G226 The Sensors for Tire Pressure are attached to the metal tire inflation valves by screws and can be reused after replacing the tires or wheels. The following components are integrated in each Sensor for Tire Pressure: • Transmitter antenna. • Pressure sensor. • Temperature sensor. • Measuring and control electronics. • Battery. The pressure sensor, temperature sensor, and measuring and control electronics integrated into each, result in an intelligent sensor. The pressure sensor records the momentary tire pressure (absolute pressure measurement) and sends the measured data to the Tire Pressure Monitoring Control Module J502 for evaluation purposes. The temperature sensor has two functions: • To compensate for the temperature- dependent changes in tire pressure. • For diagnostic purposes. If a defined temperature threshold is exceeded, the temperature sensor stops radio transmission. (For further details, refer to Temperature Cut-Out.) Temperature compensation is controlled by the Tire Pressure Monitoring Control Module J502. The measured tire pressures are normalized to a temperature of 68°F (20°C). Sensor for Tire Pressure Front Left G222 Front Right G223 Rear Left G224 Rear Right G225 Spare Tire G226 Metal Valve Body SSP219/009 SSP219/029 Depending upon the vehicle marketing area, two different carrier frequencies are used for radio transmission: • The carrier frequency of 433 MHz is permitted in most countries. • A 315 MHz carrier frequency is used in the United States and Canada and in a few other countries. The carrier frequency is printed on the sensors, antennas and control units. It can also be identified by the part number. The tire pressure monitoring system only works with system components with the same carrier frequency. The air pressure in a closed system changes in proportion to temperature. In normal circumstances, a temperature change of 18°F (10°C) results in a pressure change of 1.45 psi (10 kPa). To avoid inaccurate settings, special care must be taken to ensure that the tire pressures are checked, corrected, and stored when the tires are cold. 40 Tires — Tire Pressure Monitoring Explanatory notes: Atmospheric pressure is the term used to describe the air pressure at the earth’s surface. At mean sea level, this pressure averages about 14.7 psi (101.3 kPa), also commonly referred to as 1 atmosphere or 1 bar for practical applications (more precisely, 1 bar is equivalent to 0.98697 atmosphere, or 14.51 psi (100kPa)). Relative pressure indicates a pressure using atmospheric pressure as the starting point. Absolute pressure is the pressure using zero pressure as the starting point. 41 Tires — Tire Pressure Monitoring SSP219/011 SSP219/046 The transmitter antenna of each Sensor for Tire Pressure sends the following information: • Individual ID number (ID code). • Momentary tire pressure (absolute pressure). • Momentary tire air temperature. • Condition of integrated battery. • Status, synchronization, and control information required for safe data transfer. This information is contained in a data message 12 bytes in length. The data transfer is frequency-modulated and the transfer time is approximately 10 ms. Each tire pressure sensor has an individual ID number (ID code) which is used for the purpose of “own wheel recognition.” You can find more information in the descriptions of the Tire Pressure Monitoring Control Module J502, and Own Wheel Recognition. Temperature cut-out Electronic components are sensitive to high temperature. This can cause components to malfunction or fail. In order to avoid generating erroneous information, no further radio signals (data messages) are sent when the Sensor for Tire Pressure registers a temperature of approximately 248°F (120°C). Shortly before the Sensor for Tire Pressure turns off the transmitting electronics, the Tire Pressure Monitoring Control Module J502 is informed that a “temperature cut- out” is imminent. A fault message to this effect is then stored in the fault memory. If the temperature drops below a defined limit, the sensor will again enter radio mode. If a temperature cut-out is activated for one or more sensors, the yellow message symbol appears. The power supply to the Sensors for Tire Pressure The measuring, control and transmitting electronics in the Sensors for Tire Pressure receive their power supply from an integrated lithium battery. To prolong the service life of the Sensors for Tire Pressure for as long as possible, the control electronics include an ingenious “energy management system.” 42 Tires — Tire Pressure Monitoring SSP219/045 6 7 30 50 40 20 SSP219/040 43 Tires — Tire Pressure Monitoring The energy management system Relatively few measured-data transmissions are needed for the tire pressure measurements. However, a loss of pressure must be detected immediately and indicated to the Tire Pressure Monitoring Control Module J502. The energy management system can differentiate between the normal transfer mode and the high-speed transfer mode, because there are differing measuring and transfer intervals for each mode. When the tire pressure readings are constant, the Sensors for Tire Pressure are in normal transfer mode. If a loss of pressure of more than 2.9 psi (20 kPa) per minute occurs, the Sensor for Tire Pressure immediately is switched to a high-speed transfer mode. In this way, the energy management system keeps the load on the sensor battery as small as possible and ensures high-reliability monitoring at the same time. A theoretical battery service life of up to 7 years is therefore possible. The batteries are an integral part of the Sensors for Tire Pressure. When a sensor battery looses its charge, the sensor must be replaced. The theoretical battery service life can be interrogated using the self-diagnosis (refer to the Repair Manual). SSP219/010 SSP219/018 Normal Transfer Mode High-Speed Transfer Mode Measuring Interval Transfer Interval 3.5 Seconds 0.8 Second 55 Seconds Time Time Approximately 7 Years Time (Years) Vo lta ge (V ) Antennas for Tire Pressure Check: Front Left R59 Front Right R60 Rear Left R61 Rear Right R62 The Antennas for Tire Pressure Check receive the radio signals from the Sensors for Tire Pressure and transfer them to the Tire Pressure Monitoring Control Module J502 for further processing. The tire pressure monitoring system uses four Antennas for Tire Pressure Check which are installed in the wheel housings at the front left, front right, rear left and rear right behind the wheel housing liners. They are connected to the Tire Pressure Monitoring Control Module J502 by shielded high-frequency antenna wires in accordance with their installed locations. The antennas receive all the radio signals within their reception range and frequency band. Each antenna receives the radio signals from all the Sensors for Tire Pressure located in its range. The radio signals are filtered and selected in the Tire Pressure Monitoring Control Module J502 to ensure that the correct data are processed. The tire pressure monitoring system only works with system components which have the same carrier frequency (refer to Sensors for Tire Pressure). The carrier frequency is printed on the antennas and can also be identified by the part number. There is no separate antenna for the spare wheel (refer to Spare Wheel). 44 Tires — Tire Pressure Monitoring SSP219/011 SSP219/016 45 Tires — Tire Pressure Monitoring To avoid interference with the transmission of signals, defective antenna wiring must not be repaired while a high frequency transmission is in progress! If an antenna wire is damaged, the cable set must be replaced. Self-diagnosis The Antennas for Tire Pressure Check are currently not monitored by the self- diagnosis. If “no signal” is recorded in the fault memory for a Sensor for Tire Pressure, either the antenna or the antenna wiring for that sensor may be affected. A provision has been made for antenna diagnosis at a later date. You will find information regarding this in the relevant Repair Manual when it becomes available. Tire Pressure Monitoring Control Module J502 The Tire Pressure Monitoring Control Module J502 evaluates the radio signals from the Antennas for Tire Pressure Check, prioritizes these signals and transfers the relevant information to the instrument cluster. Where corresponding relevant warnings are issued by the driver information system (DIS) display. If “Save pressures!” is activated, the Tire Pressure Monitoring Control Module J502 is asked not only to store the new tire pressures but also to readapt to the previously stored sensors and their positions. You will find more detailed information under Own Wheel Recognition. Communication with the peripheral tire pressure monitoring components in the vehicle takes place via the convenience CAN data bus. The system status messages are prioritized by evaluating different limit values, as well as the pressure drop, as a function of time (the pressure drop gradient). SSP219/013 46 For this purpose, two independently stored tire pressures are saved to the Tire Pressure Monitoring Control Module J502: The first of these are the encoded tire pressures for the partly loaded condition and the fully loaded condition programmed into the Tire Pressure Monitoring Control Module J502 (refer to Repair Manual for more information about encoding the module). These pressures refer to the data on the sticker affixed to the fuel filler door and are entered with the help of the coding table. A lower pressure limit is calculated using the pressure for the “partly loaded (condition)” as the starting point (refer to description of system messages). The second tire pressure stored is set by the driver using the menu item “Save pressures!” on the Driver Information System (DIS) display (refer to the vehicle Owner’s Manual). Using the DIS menu, the driver can store his individual tire pressures (e.g. for fully loaded condition or winter tires). The pressures stored using the menu have priority over the encoded tire pressures unless they are set below the encoded lower pressure limit. Tires — Tire Pressure Monitoring Example: Coding 2 0 3 2 9 (1bar is equivalent to 0.98697 atmosphere, or 14.51 psi (100kPa)) 2.2 bar (31.9 psi (220 kPa)) partly loaded condition 2.9 bar (42.1 psi (290 kPa)) fully loaded condition 47 System Functions Operation The tire pressure monitoring system can be turned off and on with the Function Selector Switch II E272. The current tire pressures can be stored in the “Tire pressure” submenu. Storing the tire pressures Check, correct, and store the tire pressures when the tires are cold to avoid inaccurate settings. Check and correct the inflation of all the tires on the vehicle at the same time using the same tire gauge and air supply. Execute the “Save pressures!” function from the DIS menu after checking or correcting the tire pressures to avoid generating faulty signals. Ignoring these precautions and monitoring or correcting the tire pressures of different tires using a different air supply or tire gauge will lead to premature or delayed system status messages depending upon the differences in the temperature and quality of the air supply and the tolerances of the tire gauges. This also applies if the tire pressures are corrected when their temperatures are different (such as when including the spare in the tire rotation sequence), or if some tire pressures are corrected at different ambient temperatures than others (some in summer and others in winter), and the pressures are not stored each time pressure corrections are made. The desired menu option can be selected with the rotary switch/pushbutton of the Function Selector Switch II E272 (refer to operating instructions). Tires — Tire Pressure Monitoring MENU RETURN INFO 6 7 30 50 40 20 SSP219/007 Display mode Menu OFF Interrogate ©Set Help Settings Computer Clock ©Tire pressure Radio display Speed warning BACK Tire pressure 3 ON © o Save Pressures! Back Tire pressure The momentary tire pressures have been stored ©Back 48 Tires — Tire Pressure Monitoring Turning the system off and on The system can be turned off and on by the driver using the DIS menu. The yellow status message symbol for “tire pressure monitoring system off” is displayed briefly whenever the ignition is turned on and the system is off. 6 7 30 50 40 20 SSP219/038 OFF Status Messages System status messages are divided into two priority levels depending on their effect on vehicle handling and performance. Priority 1 messages have high significance and are intended for system states in which driving safety is no longer assured. Priority 1 status messages are indicated by red warning symbols on the DIS display and by acoustic chime signals. The driver is asked to check the condition of the tires immediately. Priority 2 messages have low significance and are intended for system states which are non-critical with regard to driving safety. The driver is informed about the condition of the system by yellow symbols on the DIS display. As a rule, priority 1 and 2 status messages are each further subdivided into two categories: “no position” and “position-related.” “No position” means that the system cannot give exact information regarding the fault location, or that there are several fault locations which lead to the status message “no position.” “Position-related” means that the system can determine the fault location exactly and only this location can be responsible for causing the fault. Priority 1 Messages are displayed under the following conditions: • The actual tire pressure drops below alarm threshold 2. • The actual tire pressure drops below alarm threshold 3. • The pressure loss gradient is greater than 0.2 bar per minute (2.9 psi per minute (20 kPa per minute)). Whenever “Save pressures!” is executed, the tire pressure monitoring system is turned on automatically. 49 Tires — Tire Pressure Monitoring Priority 1 messages are displayed immediately after an evaluation has been made by the system. A priority 1 message is always displayed as from alarm threshold 3! Specified tire pressure stored using the DIS menu. Actual tire pressure. Alarm threshold 1 . . . . . . is 0.2 bar (2.9 psi (20 kPa)) below the specified tire pressure stored using the DIS menu. Alarm threshold 2 . . . . . . is 0.4 bar (5.80 psi (40 kPa)) below the specified tire pressure stored using the DIS menu. 20 4 6 8 10 12 14 SSP219/021 P re ss u re 2 bar (29.02 psi (200 kPa)) 1 bar (14.51 psi (100 kPa)) Time in Seconds Case 2 Rapid pressure loss gradient > 0.2 bar/min (2.9 psi/min (20 kPa/min)), [Tire pressure loss gradient in the example is 0.4 bar/min (5.80 psi/min (40 kPa/min)).] Case 1 Sudden rapid pressure loss. 2.3 bar (33.37 psi (230 kPa)) 2.1 bar (30.47 psi (210 kPa)) 1.9 bar (27.57 psi (190 kPa)) 1.7 bar (24.67 psi (170 kPa)) Alarm threshold 3 . . . . . . is the lower pressure limit calculated from the encoded tire pressure for the partly loaded condition. For example, according to the coding table for an Audi A8 under partial load, the lower pressure limit is 1.7 bar (24.67 psi (170 kPa)) at a specified inflation pressure of 2.2 bar (31.91 psi (220 kPa)). Color Coding Rapid loss of pressure — priority 1 50 Tires — Tire Pressure Monitoring The following priority 1 messages can be displayed: This priority 1, no position status message appears when at least one of the conditions for priority 1 is fulfilled and a definite wheel position cannot be assigned. One or more wheels may be affected. This status message may also pertain to the spare wheel in certain conditions (for more detailed information, please refer to Spare Wheel). 6 7 30 50 40 20 Check tire pressure SSP219/031 This priority 1, position-related status message includes the wheel position of the fault as determined by the system. 6 7 30 50 40 20 Tire pressure, front left Tire pressure, front right Tire pressure, rear left Tire pressure, rear right SSP219/032 51 Tires — Tire Pressure Monitoring This message is displayed when the “Check” key is pressed while a priority 1 status message is indicated. If the navigation system is active, all priority 1 messages are indicated by this smaller symbol at the top of the DIS display after an initial short-term full-screen display so that route guidance can continue. The priority 1 messages are cancelled if: • all Sensors for Tire Pressure receive a tire pressure over alarm threshold 1 — 0.2 bar (2.9 psi (20 kPa)) under the stored specified tire pressure, and • the tire pressures are stored again using the DIS menu. 6 7 30 50 40 20 Check tire pressures SSP219/033 6 7 30 50 40 20 SSP219/034 52 Slow loss of pressure — priority 1, wrong pressure setting stored using the DIS menu Tires — Tire Pressure Monitoring SSP219/022 Color Coding Specified tire pressure stored using the DIS menu. Actual tire pressure. Alarm threshold 3 . . . . . . is the lower pressure limit calculated from the encoded tire pressure for the partly loaded condition. For example, according to the coding table for an Audi A8 under partial load, the lower pressure limit is 1.7 bar (24.67 psi (170 kPa)) at a specified inflation pressure of 2.2 bar (31.91 psi (220 kPa)). X X X0 Normal loss of pressure (through diffusion) 1.9 bar (27.57 psi (190 kPa)) Filling Filling P re ss u re Time in Months 2 bar (29.02 psi (200 kPa)) 1 bar (14.51 psi (100 kPa)) 1.7 bar (24.67 psi (170 kPa)) A priority 1 message is always displayed as from alarm threshold 3! This diagram shows a wrong pressure setting stored using the DIS menu. Alarm threshold 3 is established by the encoded tire pressure for the partly loaded condition. In this example, a priority 1 message is displayed when the tire pressure drops below the lower pressure limit of 1.7 bar (24.67 psi (170 kPa)). 53 Tires — Tire Pressure Monitoring Priority 2 Messages are displayed under any of the following conditions: • The actual tire pressure drops below alarm threshold 1. • The pressure differential at the wheels on the same axle is greater than 0.4 bar (5.80 psi (40 kPa)). Specified tire pressure stored using the DIS menu. Actual tire pressure. Alarm threshold 1 . . . . . . is 0.2 bar (2.9 psi (20 kPa)) below the specified tire pressure stored using the DIS menu. Alarm threshold 2 . . . . . . is 0.4 bar (5.80 psi (40 kPa)) below the specified tire pressure stored using the DIS menu. Slow loss of pressure — priority 2 • The system is turned off or unavailable due to faults. If position recognition has not been performed by the system, no priority 2 messages registering actual pressure drop or pressure differential will be displayed. Alarm threshold 3 . . . . . . is the lower pressure limit calculated from the encoded tire pressure for the partly loaded condition. For example, according to the coding table for an Audi A8 under partial load, the lower pressure limit is 1.7 bar (24.67 psi (170 kPa)) at a specified inflation pressure of 2.2 bar (31.91 psi (220 kPa)). X0 X X Time in Months Normal loss of pressure (through diffusion) P re ss u re 2.3 bar (33.37 psi (230 kPa)) 2.1 bar (30.47 psi (210 kPa)) 1.9 bar (27.57 psi (190 kPa)) 1.7 bar (24.67 psi (170 kPa)) Filling Filling SSP219/020 2 bar (29.02 psi (200 kPa)) 1 bar (14.51 psi (100 kPa)) Color Coding 54 Priority 2 messages displayed when the actual tire pressure drops below alarm threshold 1 These messages are displayed when the actual tire pressure in a wheel is 0.2 bar (2.9 psi (20 kPa)) less than the specified tire pressure stored using the DIS menu (alarm threshold 1). At the same time, the Tire Pressure Monitoring Control Module J502 must know the positions of the Sensors for Tire Pressure (priority 2, position-related). In addition, a difference of more than 0.1 bar (1.45 psi (10 kPa)) between actual tire pressure and the stored specified tire pressure must not be received from any of the other three Sensors for Tire Pressure. Tires — Tire Pressure Monitoring 6 7 30 50 40 20 6 7 30 50 40 20 Front left Front right Rear left Rear right Front left Front right Rear left Rear right SSP219/035 SSP219/036 If a wheel reaches alarm threshold 1 and if one or more of the other wheels is 0.1 bar (1.45 psi (10 kPa)) below the stored specified tire pressure, the DIS displays the yellow status message symbol and all four positions. No single position is isolated as the location of the fault. In this way, the driver is prompted to check the tire pressures of all the wheels and correct them as needed. This ensures optimum tire pressure maintenance and reduces the number of system alarms. 55 Further conditions relating to actual tire pressure drops below alarm threshold 1 The temperature value transferred by the Sensors for Tire Pressure must not be more than 27°F (15 °C) above the ambient temperature when the ignition is turned on. If this temperature threshold is exceeded, the alarm message is suppressed. The alarm messages concerning actual tire pressure drops below alarm threshold 1 are not displayed until the ignition is turned on again. The alarm messages concerning actual tire pressure drops below alarm threshold 1 are cancelled if: • a tire pressure which deviates from the stored specified tire pressure by less than 0.1 bar (1.45 psi (10 kPa)) is received from all Sensors for Tire Pressure, and • the pressures are stored again using the DIS menu. Priority 2 messages displayed when the pressure differential between wheels on the same axle is greater than 0.4 bar (5.80 psi (40 kPa)) These messages are displayed when the pressure differential between the wheels on an axle (front axle, rear axle or on both axles) is greater than 0.4 bar (5.80 psi (40 kPa)). This can occur if tire pressure correction is not performed properly, such as if a wheel has been omitted from the checking and correction routine. If this happens, the driver must recheck and correct the tire pressures and repeat the “Save pressures!” function using the DIS menu. Tires — Tire Pressure Monitoring The alarm messages concerning the condition that the pressure differential between wheels on the same axle is greater than 0.4 bar (5.80 psi (40 kPa)) are displayed immediately after the evaluation is performed. 6 7 30 50 40 20 SSP219/037 Front left Front right Rear left Rear right Front left Front right Rear left Rear right 56 Further conditions relating to the pressure differential between wheels The temperature values determined by the Sensors for Tire Pressure must not be more than 54°F (30°C) above the ambient temperature. The alarm message is suppressed when this temperature threshold is exceeded. The alarm messages concerning the condition that the pressure differential between wheels on the same axle is greater than 0.4 bar (5.80 psi (40 kPa)) are cancelled if the pressures are stored again using the DIS menu. Priority 2 messages displayed when the system is turned off or unavailable due to faults The tire pressure monitoring system can be deactivated by the driver using the DIS menu. This is expedient when wheels with Sensors for Tire Pressure are transported in the luggage compartment or when wheels without Sensors for Tire Pressure are mounted (winter wheels with snow tires for example). This status message is displayed briefly as information for the driver whenever the ignition is turned on. Tires — Tire Pressure Monitoring 6 7 30 50 40 20 SSP219/038 OFF 57 If the system is not available due to radio frequency interference, these yellow status message symbols will appear on the DIS display. This can occur when the Antennas for Tire Pressure Check receive no data messages due to interference from electromagnetic fields. Possible interference factors include stray ignition shorts to ground (spark plug wire not installed correctly) or the use of infrared headphones. The message is cancelled when the radio frequency interference is no longer present and the data messages from the Sensors for Tire Pressure have been received. This message is only indicated at vehicle road speeds greater than 3.1 mph (5 km/h). This yellow status message symbol appears on the DIS display in the event of other system disturbances, indicating that the tire pressure monitoring system is not available. (See also “Temperature cut-out.”) Examples of other system disturbances include: • Fault in the system such as an open circuit, defective Tire Pressure Monitoring Control Module J502, etc. • No radio signals are received from the Sensors for Tire Pressure such as after installing snow chains or wheels without Sensors for Tire Pressure. • The own wheel recognition and position recognition operations were not completed by the system within a driving time of 30 minutes. Tires — Tire Pressure Monitoring 6 7 30 50 40 20 6 7 30 50 40 20 SSP219/039 SSP219/040 • If data messages are received from more than five Sensors for Tire Pressure while travelling such as during the transportation of wheels with Sensors for Tire Pressure in the luggage compartment. • If the Tire Pressure Monitoring Control Module J502 has detected an erroneous code or is not properly encoded. 58 Own Wheel Recognition Each of the Sensors for Tire Pressure has its own ID code in the form of a 10-digit number. The ID codes are included in the data messages from the Sensors for Tire Pressure and are transferred continuously to the Tire Pressure Monitoring Control Module J502. The Tire Pressure Monitoring Control Module J502 defines and stores the ID codes for the Sensors for Tire Pressure belonging to the vehicle under specific conditions. This process is referred to as “own wheel recognition.” Up to five Sensors for Tire Pressure can be managed by the system (including the Sensor for Tire Pressure, Spare Tire G226). The ID codes received are compared continuously with the ID codes stored in the memory, and only the data messages of the stored sensors are processed. This ensures that signals from non-system sensors located within radio reception range do not affect the system. The own wheel recognition system is an adaptive system. The Tire Pressure Monitoring Control Module J502 recognizes when wheels with different Sensors for Tire Pressure are mounted. The “new” Sensors for Tire Pressure are recognized and stored under specific conditions through algorithmic evaluation. Tires — Tire Pressure Monitoring Sensors for Tire Pressure are only adapted to the system while the vehicle is moving. This protects the system against interference from the tire pressure monitoring systems of other vehicles parked in the vicinity, for example. When the function “Save pressures!” is invoked from the DIS menu, the Tire Pressure Monitoring Control Module J502 is requested to repeat the own wheel recognition and position assignment processes in addition to storing the new tire pressures. Transporting wheels with Sensors for Tire Pressure inside the vehicle is a source of RF interference and may cause the system to generate erroneous information. The ID codes of the individual Sensors for Tire Pressure can be displayed under various display groups with the Vehicle Diagnosis, Test and Information System VAS 5051, using function 08 — Read measured value block. 59 Tires — Tire Pressure Monitoring SSP219/041 List of own wheels (ID code) 1 ... 0000578100 2 ... 0000597200 3 ... 0000598100 4 ... 0000602300 5 ... 0000755100 List of wheel positions (ID code) Left Front ... 0000755100 Right Front ... 0000597200 Left Rear... 0000602300 Right Rear ... 0000578100 Spare ... 0000598100 ID codes MENUE RETURN INFO Tire Pressure Monitoring Control Module J502 0000602300 0000597200 0000755100 0000578100 0000598100 60 Tires — Tire Pressure Monitoring Position Recognition To be able to display position-related alarm messages to the driver, the Tire Pressure Monitoring Control Module J502 must know the locations of the Sensors for Tire Pressure on the vehicle. Position recognition is an additional function performed by the Tire Pressure Monitoring Control Module J502. It assigns the Sensors for Tire Pressure automatically and independently to the installed locations of the wheels on the vehicle at the front left, front right, rear left and rear right, as well as the spare wheel. This is made possible by the use of four receiver Antennas for Tire Pressure Check and evaluating the reception signals of varying strength from the individual Sensors for Tire Pressure. The Tire Pressure Monitoring Control Module J502 determines the theoretical positions of the Sensors for Tire Pressure (installed locations of the wheels at the front left, front right, rear left and rear right, as well as the spare wheel) using algorithmic calculations and statistics. Because of the many factors that can affect signal strength in radio transmission (e.g. shielding by metal parts, distance from transmitter to antenna, environmental influences etc.), the system cannot always determine the position of each Sensor for Tire Pressure with 100% certainty. Therefore, the term “theoretical position” is used. Monitoring function when the vehicle is stationary To ensure that the monitoring function also works when the vehicle is stationary, the Tire Pressure Monitoring Control Module J502 remains active after the ignition has been turned off. The Tire Pressure Monitoring Control Module J502 enters energy-saving mode. It self-activates at regular intervals shortly before the data messages are transmitted by the Sensors for Tire Pressure at each wheel. This function helps to preserve the vehicle battery charge and ensures that a flat tire is indicated on the DIS display before the vehicle is moved. MENUE RETURN INFO 0000602300 0000597200 0000755100 0000578100 0000598100 61 Tires — Tire Pressure Monitoring Tire Pressure Monitoring Control Module J502 List of own wheels (ID code) 1 ... 0000578100 2 ... 0000597200 3 ... 0000598100 4 ... 0000602300 5 ... 0000755100 List of wheel positions (ID code) Left Front ... 0000755100 Right Front ... 0000597200 Left Rear... 0000602300 Right Rear ... 0000578100 Spare ... 0000598100 ID codes SSP219/042 62 Spare Wheel The spare wheel has a special status in the tire pressure monitoring system. It is equipped with a Sensor for Tire Pressure, Spare Tire G226. Unlike the other wheels, the tire pressure monitoring system does not have a separate Antenna for Tire Pressure Check for spare tire pressure monitoring. The Antennas for Tire Pressure Check at each of the four wheel housings receive the data message radio signals from the Sensor for Tire Pressure, Spare Tire G226, and send these signals to the Tire Pressure Monitoring Control Module J502. The own wheel and position recognition functions identify the “fifth wheel” as a spare wheel, and it is registered as such in the Tire Pressure Monitoring Control Module J502. Tires — Tire Pressure Monitoring The tire pressure in the spare wheel can be monitored using the Vehicle Diagnosis, Test and Information System VAS 5051, using Address Word 65, Function 08, Read measured value block, Display group 13. The prerequisite for this is that the position recognition process has been completed. This is the case when “015” is displayed under Display group 19. Although the Tire Pressure Monitoring Control Module J502 “manages” the spare wheel, system alarm messages pertaining to the spare wheel are suppressed and not indicated. A priority 1, “no position” status message may be caused by the spare wheel if the tire inflation pressure is below alarm threshold 3 and position recognition has not yet been performed by the system. This could occur after “Save pressures!” has been initiated using the DIS menu or after a wheel change, but before the vehicle has been driven long enough for the system to complete the own wheel recognition and position assignment processes. The message is cancelled once position recognition has been completed by the system and the spare wheel is recognized as such. SSP219/043 63 Convenience CAN Data Bus Interface Information interchange between the Tire Pressure Monitoring Control Module J502 and the vehicle is performed by the Instrument Cluster Combination Processor J218 through the convenience CAN data bus. Information received by the Tire Pressure Monitoring Control Module J502 Tires — Tire Pressure Monitoring 3 2 1 4 5 6 0 7 10 30 50 70 100 140 180 220 260 20 40 60 80 160 200 240 120 1/2 1/1 R 0 0 890 °C 50 120 280 - + 10:02 18.01.1999 0.0 12.345 km SSP219/025 SSP219/013 Instrument Cluster Combination Processor J218 Ignition “on” For requesting that available messages be sent immediately, and for the diagnosis of terminal 15. Engine speed For suppressing the voltage diagnosis function at engine speeds below 500 rpm. System controls For activating the tire pressure monitoring function. “Save pressures!” request Initiated by the driver from the DIS menu. Road speed For enabling the own wheel recognition and position recognition functions. Ambient temperature For filtering the messages. Tire Pressure Monitoring Control Module J502 System active Information for the self-diagnosis. Signal status For displaying the various system messages. System state Answer to system conditions. Convenience CAN Data Bus Information sent by the Tire Pressure Monitoring Control Module J502 64 Tire Pressure Monitoring Functional Diagram Tires — Tire Pressure Monitoring 15+ 30+ 31 G222 G223 G224 G225 G226 TV14 CAN-HIGH CAN-LOW S S J502 R62R61R60R59 INFO 65 Tires — Tire Pressure Monitoring SSP219/019 Input Signal Output Signal Positive Ground Convenience CAN Data Bus Components E272 Function Selector Switch II G222 Sensor for Tire Pressure, Front Left G223 Sensor for Tire Pressure, Front Right G224 Sensor for Tire Pressure, Rear Left G225 Sensor for Tire Pressure, Rear Right G226 Sensor for Tire Pressure, Spare Tire J218 Instrument Cluster Combination Processor J502 Tire Pressure Monitoring Control Module R59 Antenna for Tire Pressure Check, Front Left R60 Antenna for Tire Pressure Check, Front Right R61 Antenna for Tire Pressure Check, Rear Left R62 Antenna for Tire Pressure Check, Rear Right TV14 Data Link Connector (DLC) Wire Connector X Terminal 58s Gold Contact Color Codes 3 2 1 4 5 6 0 7 10 30 50 70 100 140 180 220 260 20 40 60 80 160 200 240 120 1/2 1/1R0 0 890 °C 50 120 280 - + 10:02 18.01.1999 0.0 12.345 km 30+ 15+ X S S J218 E272 0 1 S MENUE RETURN 66 Steering — Servotronic II Servotronic II Variable Effort Power Steering The Servotronic II variable effort power steering system uses the proven basic steering valve design and the same principles to vary the steering wheel effort, but incorporates several improvements in the feedback mechanism over the previous design. The basic valve is a rotary steering valve with a roller bearing encased in a steering box. The principles used to vary the steering wheel effort still include active hydraulic feedback from the feedback mechanism: • Valve resistance increases with vehicle speed. Therefore, the effort required to move the steering wheel is increased to enhance straight-line stability at higher speeds. • Power steering assist to the mechanism at the steering gear is not limited at high vehicle speeds. Feedback Mechanism The feedback mechanism converts the rotation of the steering valve into axial feedback piston movement. The ball screw feedback mechanism used in the previous design requires: • A piston stroke in two directions, depending upon the rotation direction of the steering valve. • Two feedback chambers. The Servotronic II uses a feedback mechanism with centering lugs to convert steering valve rotation into feedback piston axial movement. In this design the piston stroke is always in the same direction regardless of the rotation direction of the steering valve. The benefits of this design include: • Only one feedback chamber is required. • Greater feedback piston surface area. • Simplified hydraulic switching. • Increased resistance to contamination. • Wider spread of the variation of effort curve is possible. Steering — Servotronic II 67 Servotronic II System Overview R T + - Speedometer Vehicle Speed Sensor (VSS) G22 Control Module with Indicator Unit in Instrument Panel Insert J285 Pump Rotary Slide Valve Torsion Bar Steering Box Centering Unit Torsion Bar Electro-Hydraulic Converter 78500001 CAN Data Bus Networking Overview The ignition switch, and multifunction and Tiptronic steering wheel control signals are registered through Steering Column Electronic Systems Control Module J527. Diagnosis System J220 J217 J104 J234 J527 G85 J519 E87 J393 J388 J386 J387 J389 J446 J136 J527 J453 R J401 Gate- way TRACK SEEK CD CDC AM FM 1 DOLBY SYSTEM 2 1 2 TAPE PLAY SDE BASS MIDDLE TREBLE BALANCE FADER 1 2 3 4 5 6 EJECT Audi symphony AS TP RDS RANDOM FR FF TUNE SCAN EJECT R T + - J285 78500015 Electrical System 68 Extended CAN Data Bus System The new Audi A4 and A6 are equipped with a widely extended CAN data bus system. Due to the ever increasing number of control modules installed in the vehicle and the associated requirement for data exchange, the importance of the CAN data bus system increases significantly. For communication between the installed control modules and the diagnostic tester, two diagnosis wires (K and L) are available. The newly developed adapter VAS 6017A enables communication with all control modules. SSP254/112 Components E87 A/C Control Head G85 Steering Angle Sensor J104 ABS Control Module with EDL/ASR/ESP J136 Memory Seat Control Module (Optional) J217 Transmission Control Module J220 Motronic Engine Control Module J234 Airbag Control Module J285 Control Module with Indicator Unit in Instrument Panel Insert J386 Door Control Module, Driver’s Side J387 Door Control Module, Passenger Side J388 Door Control Module, Rear, Left J389 Door Control Module, Rear, Right J393 Central Control Module for Comfort System J401 Control Module for Navigation with CD Mechanism J446 Control Module for Parking Aid J453 Control Module for Multi-Function Steering Wheel J519 Vehicle Electrical System Control Module J527 Steering Column Electronic Systems Control Module R Radio Color Coding Drivetrain CAN Data Bus Convenience CAN Data Bus Infotainment CAN Data Bus Diagnosis Connection K Wire Diagnosis Connection L Wire (2nd K wire) Electrical System 69 Electrical System 70 Compass The compass and its control button are integrated into the inside rear view mirror housing. When the ignition switch is on, the direction of vehicle travel is displayed. 78500016 The compass is capable of distinguishing eight primary directions: • North (N) • Northeast (NE) • East (E) • Southeast (SE) • South (S) • Southwest (SW) • West (W) • Northwest (NW) For the most accurate readings, the compass must be calibrated and adjusted to match the compass set zone for the area in which the vehicle is operated. Electrical System 71 Calibrating the Compass 1. Turn the ignition switch to position II. The rearview mirror display should show the letter “C.” 2. If “C” is not displayed, use a ballpoint pen or similar tool to press the button on the bottom of the mirror for about 6 seconds until “C” is displayed, then release the button. 3. Calibrate the compass by driving the vehicle in circles at a speed of 5 mph (8 km/h) or less until the mirror display shows a direction symbol (N, NE, etc.). Normally this will take about two circles. Calibration The compass is self-calibrating. It will display “C” until it calibrates itself during vehicle operation or is calibrated manually. The compass may require calibration if: • The vehicle has been involved in a collision or experiences a jarring force that is sufficient to disturb the inherent magnetic field of the vehicle. • The vehicle has been operated near a high magnetic field such as a car wash or overhead train. • The vehicle battery has been disconnected for a long period of time. The compass will eventually correct itself for these conditions during normal vehicle use. Manual calibration will speed the process. 78500017 Recessed Control Button 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Compass Set Zones Variations in the earth’s magnetic field will cause changes in the compass readout when the vehicle is driven from one compass set zone to another. However, since the magnetic variation between adjacent zones is only 4 degrees, for most driving situations, resetting the compass should only be necessary if the vehicle has crossed more than one zone. The precise points at which the set zones change cannot be accurately plotted. Vehicles operated in an area where zones converge should not normally need to have the compass reset every time the vehicle crosses from one zone to another. Setting the Compass Zone 1. Determine the appropriate compass set zone for your location from the illustration. 2. Turn the ignition switch to position II. 3. Using a ballpoint pen or similar tool, press and hold the button on the bottom of the rearview mirror for about 3 seconds until a zone number appears on the display, then release the button. The compass automatically defaults to zone 8. 4. Alternately press and release the button until the desired zone number appears. 5. About 10 seconds after releasing the button, the directional display will appear, completing the zone setting process. 78500002 78500017 Electrical System 72 Recessed Control Button Electrical System 73 Bi-Xenon Headlights Components The headlight modules consist of the following components: • Ballast Unit for Gas-Discharge Headlight, Left J426; or Ballast Unit for Gas-Discharge Headlight, Right J427 • Left Headlight Beam Adjusting Motor V48 or Right Headlight Beam Adjusting Motor V49. • Left High Beam Lamp L125 or Right High Beam Lamp L126 (normal H7 lamps). • High-Intensity Gas-Discharge Lamp L13. • Housing with laminated clear glass lens. Both headlamps can be switched from asymmetrical to symmetrical low beam for traveling in countries where driving is on the left side of the road. Right Front Turn Signal Light M7 High-Intensity Gas-Discharge Lamp L13 (Low and High Beam) Right High Beam Lamp L126 (Normal H7 Lamp — Additional High Beam, Headlight Flasher) Housing with Laminated Clear Glass Lens 78500003 Functional Principles High beam When the bi-xenon headlights are set to high beam, the entire light cone reflected from each High-Intensity Gas-Discharge Lamp L13 is effective. In addition, the Left High Beam Lamp L125 and Right High Beam Lamp L126 (normal H7 lamps) are turned on. Low beam When the bi-xenon headlights are set to low beam, an electro-magnetically actuated screen is moved into position in front of the reflector, to block out part of the light cone. High-Intensity Gas-Discharge Lamp L13 Reflector ElectromagnetScreen Lens 78500004 74 Electrical System High Beam Low Beam 75 Electrical System Audi Telematics by OnStar Audi Telematics by OnStar is an in-vehicle communication system using cellular telephone, internet, and global positioning system (GPS) technologies to provide safety, security, and convenience services at the touch of a button. New services will be added as the technology advances and the market demands. Refer to the OnStar user’s instructions for details on features and their availability. GPS is an array of 24 satellites that orbit the earth and constantly broadcast radio signals. The OnStar Telephone/Telematic Control Module J526 in the vehicle receives the GPS data, decodes it, and transmits the vehicle location to the OnStar call center using cellular technology. OnStar Design Principles • Minimize the time the driver spends with eyes off the road, or hands off the wheel. • Minimize the number of steps required to perform a task. • Create a common interface for interaction with the system. • Preclude the use of systems that make excessive demands of the driver. OnStar System Components 78500012 Auxiliary Antenna (Telematic) R90 Telematic Control Head E264 Telephone/Telematic Control Module J526 Multi-Function Steering Wheel Driver Information System Display 76 Electrical System 77 Electrical System How OnStar Works OnStar relies on the cellular telephone network for communication between the vehicle and the OnStar advisor, and uses GPS data to determine the vehicle location. • When the OnStar button is pushed, GPS vehicle location longitude and latitude data is transmitted along with the vehicle station identification code. • The receipt of this information at the OnStar call center triggers a display of the customer account information and GPS map location to the OnStar advisor. • OnStar modems switch the vehicle from data to voice transmission. Voice and data are not transmitted simultaneously. Most areas in the United States and Canada have two cellular service providers, assigned to either band A or band B. With a single OnStar button press, the system will attempt to connect four times, alternating between these bands with each attempt. The fourth call attempt will route to a different number, will not transmit data, and will yield a “Fail to Voice” result with no airtime charges for the call. An emergency button press or an air bag deployment notification will retry for a connection continuously. For further information about OnStar, please refer to the Self-Study Program Audi Telematics by OnStar, Course Number 993203. 78500013 GPS Satellites Mobile Telephone Switch Long Distance Carrier Switch OnStar Call Center OnStar Advisor PC Application Cellular Network In-Vehicle OnStar System: • Telephone/Telematic Control Module J526 • Inside Microphone R74 • Telematic Control Head E264 • Auxiliary Antenna (Telematic) R90 (Includes GPS and Cellular Antennas) 78 Electrical System 78500014 Audi Digital Phone by Motorola A new Audi hands-free digital phone by Motorola is available for vehicles equipped with Audi Telematics. This V-series portable telephone can be used as a stand-alone cellular phone or as a hands-free phone when installed in the vehicle cradle. The following features are available with this option: • Phone cradle in front center armrest. • Concealed microphone, antenna, and dedicated speaker. • FM stereo. • Wireless web communication enabled by WAP 1.1 browser. • Voice recognition for voice-activated dialing and voice notes to record personal messages. • Multi-language support. • Digital phone book with capacity for up to 400 names. • Up to 20 phone numbers can be stored for recall through voice-recognition activation. • Telephone numbers are displayed on the Driver Information System screen. • Personal information management system. • Turbo dialing. • 96 by 64 graphic display. • Integrated headset jack. • Ring sound style can be changed to one of 32 different tones. • 180 minutes talk time and 300 hours standby time. • CDMA operation: 800/1900 CDMA, 800 amps. • TDMA operation: 800/1900 TDMA, 800 amps. When the Audi digital phone by Motorola is mounted in the vehicle phone cradle, the Telephone/Telematic Control Module J526 mutes the radio whenever the phone is placing or receiving calls. This allows hands- free operation. 79 Electrical System Symphony II Radio Transport Mode New Audi vehicles equipped with Symphony II radios are shipped from the factory with their radios in transport mode. This reduces the parasitic voltage drain on vehicle batteries during shipping and storage. Normally, the Symphony II radio transport mode is deactivated during the new vehicle pre-delivery inspection process, prior to delivery of the vehicle to the customer. If the radio is in transport mode, pressing any radio button when the ignition switch is on will cause “TRANSPORT” to come up on the radio display. Deactivating Transport Mode The transport mode can be deactivated using the Vehicle Diagnosis, Test and Information System VAS 5051 and K-lead adapter VAS 6017A. The transport mode deactivation sequence is accessed through Address Word 56 – Radio. Refer to Audi Technical Bulletin C 91-01-07 for more information. 78500018 80 Notes 81 An on-line Knowledge Assessment (exam) is available for this Self-Study Program. This Knowledge Assessment may or may not be required for Certification. You can find this Knowledge Assessment in the Learning Management Center at: www.accessaudi.com For assistance please call: Certification Program Headquarters 1-877-CU4-CERT (1-877-284-2378) (8:00 a.m. to 8:00 p.m. EST) Knowledge Assessment