Audi R8 2008 User Manual

Service Training

The 2008 Audi R8
Vehicle Introduction

Self-Study Program 99B703

Audi of America, Inc.
Service Training
Printed in U.S.A.
Printed 9/2007
Course Number 99B703

©2007 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 latest electronic repair
literature 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.

Table of Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . .1

Body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Occupant Protection . . . . . . . . . . . . . . . . . . . . 10

Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Transmissions/Driveline . . . . . . . . . . . . . . . . . . 30

Running Gear . . . . . . . . . . . . . . . . . . . . . . . . 38

Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Air Conditioning. . . . . . . . . . . . . . . . . . . . . . . 54

Self-Study Programs . . . . . . . . . . . . . . . . . . . . 58

Knowledge Assessment . . . . . . . . . . . . . . . . . . 59

The Self-Study Program teaches the design and function of new vehicle models,
automotive components or technologies.

The Self-Study Program is not a Repair Manual!
The values given are intended as a guideline only and refer
to the software version valid at the time of publication of the SSP.

For maintenance and repair work, always refer to the current technical literature.

Reference

The Self-R

Note

i

Notes

ii

Audi R8 Overview

Introduction

Audi made motor sport history with the Audi R8 race
car - a formula that stirred the enthusiasm of people
throughout the world. This vehicle has now found its
way into production in the Audi R8 high-performance
sports car. Among many other attributes, the Audi
R8 accelerates from 0-60 MPH in 4.4 seconds, has no
electronically governed top speed, is designed with an
optimized front-to-rear weight distribution of 44:56, and
has very high directional stability.

Some main features of the Audi R8 include the following:

– Audi Space Frame ASF.
– 4.2L FSI High-Revving Engine.
– R-tronic Transmission.
– Front Viscous Coupling.
– Limited Slip Differential.
– Audi Magnetic Ride.
– Hi-Performance Brakes.

1

Introduction

Audi Neckarsulm

The Audi R8 is assembled in Neckarsulm,

Germany. Vehicles are produced largely by

hand with a small-scale production of 20

vehicles per day.

Over 250 employees with a high level of

workforce qualification, skill, and in-depth

experience work at the R8 production

facility. More than 39 million dollars were

invested in the site.

2

Notes

3

Body

Dimensional Overview

The luggage compartment of the Audi R8 accommodates
almost 3.5 cu. ft. (DIN) and approximately 3.2 cu. ft. (DIN)
of additional space is provided behind the seats.

Weights

Unladen Weight 3605 lb (1635 kg) - with Manual Transmission

3616 lb (1640 kg) - with R-tronic Transmission

Permissible Laden Weight 4101 lb (1860 kg) - with Manual Transmission

4112 lb (1865 kg) - with R-tronic Transmission

Turning Circle Diameter 37.8 ft (11.80 m)

Fuel Tank 24 Gallons

Motor Oil Quantity 15 qt (14.2 l) (Including Filter Replacement)

4

Body

Body Dimensions

Length 174 in (4431 mm)

Width 74.9 in (1904 mm)

Height 49.1 in (1249 mm)

Wheelbase 104 in (2650 mm)

Front Track Width 64.2 in (1632 mm)

Rear Track Width 62.7 in (1558 mm)

5

Body

Audi Space Frame (ASF)

The body design of the R8 incorporates Audi Space
Frame technology; the result is an extremely rigid,
lightweight aluminum body offering the following
benefits:

– Significant Weight Reduction.
– High Strength.
– High Static and Dynamic Torsional Rigidity.

6

Body

7

Body

Underbody

Always use the lifting position mounting points specified
above. Do not position jack or lift at any other point.
Numerous ventilation points ensure sufficient cooling of
the engine and other components.

The diffusers at front and rear enhance driving stability.
An intact underbody is essential for correct function of
the Audi R8.

8

Notes

9

Occupant Protection

Occupant Protection System
in the Audi R8

The Audi R8 is a high-end luxury sports car. The
occupant protection system is in keeping with vehicle
driving dynamics and occupant safety needs.

The occupant protection system of the Audi R8 includes
the following components and systems:

– Airbag Control Module.
– Front Dual-Stage Airbags.
– Side Airbags.
– Knee Airbags.
– Front Crash Sensors.
– Side Crash Sensors.
– Safety Belt Tensioners and Belt Force Limiters.
– Audi Backguard.
– Battery Interrupt Igniter.
– Safety Belt Switch.
– Latch Child Seat Fixture.
– Passive Occupant Detection System (PODS).

10

Occupant Protection

E24 – Driver’s Safety Belt Switch
E25 – Front Passenger’s Safety Belt Switch
G179 – Driver’s Side Airbag Crash Sensor
G180 – Front Passenger’s Side Airbag Crash Sensor
G283 – Driver’s Front Airbag Crash Sensor
G284 – Front Passenger’s Front Airbag Crash Sensor
G452 – Seat Occupied Recognition Pressure Sensor
G453 – Seat Occupied Recognition Safety Belt Force
Sensor
G551 – Driver’s Belt Force Limiter
G552 – Front Passenger’s Belt Force Limiter
J234 – Airbag Control Module
J285 – Instrument Cluster Control Module
J393 – Comfort System Central Control Module
J533 – Data Bus On Board Diagnostic Interface
J623 – Engine Control Module (ECM)

J706 – Seat Occupied Recognition Control Module
K19 – Safety Belt Warning Lamp
K75 – Airbag Malfunction Indicator Lamp (MIL)
K145 – Front Passenger’s Airbag Disabled
Indicator Lamp
N95 – Driver’s Airbag Igniter
N131 – Front Passenger’s Airbag Igniter 1
N132 – Front Passenger’s Airbag Igniter 2
N153 – Driver’s Safety Belt Tensioner Igniter 1
N154 – Front Passenger’s Safety Belt Tensioner Igniter 1
N199 – Driver’s Side Airbag Igniter
N200 – Front Passenger’s Side Airbag Igniter
N250 – Driver’s Airbag Igniter 2
N253 – Battery Interrupt Igniter
N295 – Driver’s Knee Airbag Igniter
N296 – Front Passenger’s Knee Airbag Igniter

11

Occupant Protection

Airbag Control Module J234

The electronics integrated into the Airbag Control Module
detect and evaluate vehicle acceleration and deceleration
in order to identify a vehicle collision. In addition
to internal sensors in the control module, external
sensors are also used to detect vehicle acceleration and
deceleration during a collision.

J234 recognizes a collision only from the information
provided by the sensors, deciding when and which safety
components to activate once all sensor information has
been evaluated. Front, side and rear impact collisions can
be recognized by J234.

Another purpose of J234 is to activate the corresponding
restraint systems (safety belt tensioner or safety belt
tensioner and airbag), depending on the type and
severity of the impact, and to report the crash event to
other vehicle systems.

J234 has the following main tasks:
– Crash Recognition (Front, Side, Rear).
– Defined Triggering of Safety Belt Tensioners, Airbags

and Battery Interrupt.

– Defined Triggering of the Second Front Airbag Stage.
– Evaluation of All Input Information.
– Continuous Monitoring of the Entire Airbag System.
– Independent Power Supply with a Capacitor for a

Defined Period of Time (Approximately 150 ms).

– Fault Display by a Failure Warning Lamp.
– Reporting of a Crash Event to Other System

Components through the Powertrain CAN-Bus or
Discrete Crash Output (Conventional Wiring).

– Activation of the Safety Belt Warning Lamp.
For information on which components must be replaced

after an accident, please refer to the appropriate repair
manual.

J234 can only be replaced using a VAS scan tool with
online capabilities, using the Guided Fault Finding or
Guided Functions.

J234 must be coded and adapted according to the
respective vehicle. If the coding and/or adaptation is not
performed properly, malfunctions could occur in other
vehicle systems, for example, in the ESP.

12

Occupant Protection

Data Transfer

Airbag Control Module J234 is a member of the
Powertrain CAN-bus.

J234 relays information over the Powertrain CAN-bus:
– Activation of Airbag Malfunction Indicator Lamp K75.
– Activation of the Safety Belt Warning System.
– Diagnostic Data.
– Crash Signal.
– ESP Data.
– Passenger’s Front Airbag Active / Inactive Status.

J234 evaluates the following information from the data
bus:

– Dimming for the Passenger’s Airbag Disabled
Indicator Lamp.

The information that a crash has occurred is transmitted
on the CAN-bus to other control modules to unlock the
vehicle doors, shut OFF the fuel pump, and activate the
emergency flasher system.

Airbag Malfunction Indicator
Lamp K75

K75 is located in Instrument Cluster Control Module J285
and is illuminated via the CAN-bus.

Rear Impact Recognition

During a rear impact collision, the vehicle is strongly
accelerated in the driving direction.

Crash sensors in J234 and Crash Sensors G283 and G284
recognize this vehicle acceleration and send their signals
to J234.

If the signals exceed a specified value, the pyrotechnic
safety belt tensioners the battery interrupt igniter are
activated.

Reference

For more information about the
Occupant Protection System, refer to
the 2008 Audi TT Vehicle Introduction,
Self Study Program 991703.

13

Engine

Technical Features

The following are some commonalities between the RS4
engine and the R8 engine:

– Fuel Straight Injection.
– Roller Cam Rocker Arms with Hydraulic Lifters.
– Chain Drives for Camshafts and Accessories.
– Variable Camshaft Adjustment for Intake and Exhaust

Camshafts.

4.2L V8 FSI Engine

Main features which are unique to the R8 engine include
the following systems:

– Dry Sump Lubrication.
– Crankcase Ventilation.
– Cooling.
– Air Intake.
– Exhaust.

14

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Technical Data

Reference

For more detailed information about the

4.2L FSI engine, refer to the Audi 4.2­liter V8 FSI Engine, Self-Study Program

924603.

Engine

Specifications

Engine ID Letters BYH

Type V8 Engine with 90° V Angle

Cylinder Capacity in cm3 4163

Power in Hp (kW) 420 (309) at 7800 rpm

Torque in Lb-ft (Nm) 317 (430) at 4500-6000 rpm

Bore in Inches (mm) 3.3 (84.5)

Stroke in Inches (mm) 3.7 (92.8)

Compression 12.5:1

Cylinder Spacing in Inches (mm) 3.5 (90)

Ignition Sequence 1-5-4-8-6-3-7-2

Engine Weight in lbs (kg) 491

Engine Management Bosch MED 9.1

Exhaust Gas Recirculation Internal

Exhaust Gas Cleaning 3-Way Catalytic Converter, Secondary Air System

Emission Standard EU IV / LEV II

15

Engine

Crankcase Ventilation

The crankcase is ventilated through both cylinder heads.
A large settling chamber is located in the oil tank. The
tank acts as a gravity oil separator. A fine oil separator is
connected with plastic hoses behind the oil tank.

Crankcase

Ventilation

Oil-Free

Blow-By

Gases

When blow-by gas has passed through the fine oil
separator, oil-free gas can then be delivered to the intake
downstream of the throttle. Separated oil is returned
through the oil return line.

Cyclone in

the Oil Tank

Oil Return Feed

Crankcase

Ventilation

16

Oil System

Engine

The R8 engine uses a dry sump lubrication system. This
system includes an external oil pump, cooler, and tank.
There are a few advantages of having an external pump:
the engine is placed lower in the vehicle because the
oil pan is smaller, oil starvation does not occur, and the
pump can be replaced much more easily than one of a
wet sump system.

Oil Filter

Module

Engine Oil

Circuit

The oil filter module is easily accessible, positioned in
the inner V of the engine. The filter insert can be easily
replaced without special tools.

Oil Filter Neck

Oil Cooler

Oil Pump

Oil Tank

17

Engine

Service

There are four screws which must be removed in order to
drain the oil from the engine; three from the oil pan, one
from the oil tank.

Do not loosen the two screws specified in the illustration
below.

Caution: Do not loosen or remove these

screws, as this is the pressure oil connection

of the oil pump.

Oil Tank Screw

Oil Pan Screws

18

Cooling System

Supply circuit

Return circuit

Engine

Coolant

Equalization

Tank

Auxiliary

Water Pump

Radiator, Right

Radiator, Center

Pump

Valve Unit

Coolant

Pump

Oil Cooler

Radiator, Left

19

Engine

Air Intake

The air intake system of the R8 engine begins at both
the right and left sideblades.

Audi R8 Intake System

Throttle

Valve Control

Modules

From there air rushes through both air filters, both Mass
Air Flow (MAF) sensors, both throttles, and the single
length runners; past the manifold flaps; and into the
combustion chambers.

Mass Air Flow

Sensors

Air Intake from the

Right-Hand Sideblade

Air Intake from

the Left-Hand

Sideblade

Intake Manifold Flaps

20

Notes

21

Engine

Fuel System

Fuel Metering

Valve 2 N402

Fuel Metering

Valve N290

High-Pressure

Fuel Pump 2

High-Pressure

Fuel Pump 1

Low Fuel Pressure

Sensor G410

Reference

For a description of the system’s
operating mode, refer to SSP 924603

- The Audi 4.2L V8 FSI Engine. The main
difference with this system is that it
uses two high-pressure pumps.

Leakage Line

22

High Pressure

Low Pressure

Depressurized

Fuel (Rail) 2

Engine

Fuel Pressure Sensor G247

To Fuel Injectors N83 - N86

(Cylinders 5-8)

Pressure Limiting Valve (136 Bar)

Fuel (Rail) 1

Return Line

Fuel Injectors N30 - N33

(Cylinders 1-4)

Fuel Tank

Transfer Fuel

Pump (FP) G6

Fuel Pump (FP)

Control Module J538

23

Engine

Exhaust System

The Audi R8 has a very unique downstream exhaust
design. During the development of the exhaust system,
special emphasis was placed on optimizing flow
resistance. The rear exhaust incorporates both post
converters and mufflers in the same assembly.

Audi R8 Exhaust System

Another new aspect of this system is that the exhaust
from both banks enter the assembly from their
respective sides but then cross over through assembly
and exit from the opposite side they entered.

Bank 1

Primary Catalytic

Converter

Bank 2

Exhaust Flap

Bank 2

Primary Catalytic

Converter

Secondary

Catalytic

Converters

Bank 1

Exhaust Flap

24

Notes

25

Engine

Engine Management System Overview

Sensors

Mass Air Flow (MAF) Sensor G70

Intake Air Temperature (IAT) Sensor G42

Throttle Position (TP) Sensor G79

Accelerator Pedal Position Sensor 2 G185

Engine Speed (RPM) Sensor G28

Knock Sensors (KS) 1+2 G61, G66

Fuel Pressure Sensor G247

Camshaft Position (CMP) Sensor G40

Camshaft Position (CMP) Sensor 3 G300

Throttle Valve Control Module J338

Throttle Drive Angle Sensors 1+2 for Electronic

Power Control (EPC) G187, G188

Clutch Pedal Switch F36

Clutch Pedal Starter Interlock Switch F194

Engine Coolant Temperature (ECT) Sensor G62

Low Fuel Pressure Sensor G410

Intake Manifold Runner Position Sensor G336

Heated Oxygen Sensor (HO2S) G39

Oxygen Sensor (O2S) Behind Three Way Catalytic

Converter (TWC) G130

Brake Booster Pressure Sensor G294

Brake Light Switch F

Brake Pedal Switch F47

PowerTrain CAN

Data Bus

Engine Control

Module (ECM) J623

Engine Control

Additional signals:

Cruise Control System On / Off

Terminal 50

Door Contact Wake-Up from Comfort System Central

Control Module J393

Camshaft Position (CMP) Sensor 2 G163

Camshaft Position (CMP) Sensor 4 G301

Engine Speed (RPM) Sensor G28

Knock Sensors 3+4 G198, G199

Heated Oxygen Sensor (HO2S) 2 G108

Oxygen Sensor (O2S) 2 Behind Three Way Catalytic

Converter (TWC) G131

Intake Manifold Runner Position Sensor 2 G512

Additional signals:

Door Contact Wake-Up from Comfort System Central

Control Module J393

26

Engine Control

Module (ECM) 2

J624

Engine

Actuators

Fuel Pump Control Module J538
Transfer Fuel Pump (FP) G6

Ignition Coils 1-4 with Power Output Stage
N70, N127, N291, N292

Fuel Metering Valve N290

Evaporative Emission (EVAP) Canister Purge Regulator Valve N80

Right Electro-Hydraulic Engine Mount Solenoid Valve N145

Intake Manifold Runner Control (IMRC) Valve N316

Starter Relay J53, Starter Relay 2 J695
Exhaust Flap Valve 1 N321
Leak Detection Pump (LDP) V144

Fuel Injectors, Cylinders 1-4 N30-N33

Camshaft Adjustment Valve 1 N205
Camshaft Adjustment Valve 1 (exhaust) N318

Diagnostic

Connection

Throttle Valve Control Module J338
Throttle Drive (for Electronic Power Control (EPC)) G186

Coolant Circulation Pump Relay J151
After-Run Coolant Pump V51

Oxygen Sensor (O2S) Heater Z19
Oxygen Sensor (O2S) 1 (behind Three Way Catalytic Converter
(TWC)) Heater Z29

Intake Air Switch-Over Valve N335

Secondary Air Injection (AIR) Pump Relay J299
Secondary Air Injection (AIR) Pump Motor V101
Secondary Air Injection (AIR) Solenoid Valve N112

Brake Booster Relay J569
Brake System Vacuum Pump V192

Engine Component Power Supply Relay J757

Motronic Engine Control Module (ECM) Power Supply Relay
J271

Additional signals:

Engine speed
Coolant Fan Control (FC) Control Modules 1 + 2 J293, J671
Ignition Coils 5-8 with Power Output Stage N323-N326

Camshaft Adjustment Valve 2 N208
Camshaft Adjustment Valve 2 (exhaust) N319

Cylinders 5-8 Fuel Injectors N83-N86

Oxygen Sensor (O2S) 2 Heater Z28
Oxygen Sensor (O2S) 2 (behind Three Way Catalytic Converter
(TWC)) Heater Z30

Fuel Metering Valve 2 N402

Left Electro-Hydraulic Engine Mount Solenoid Valve N144

Throttle Valve Control Module J338

27

Engine

Control Module Communications

The Engine Control Module J623 (ECM, master)
computes and controls the signals from the actuators
for cylinder bank 1.

Most sensors are connected to the ECM.

Both control modules are connected to the CAN data
bus; the slave control module is used as a receiver only.

The load signals required to compute and control
the signals for the actuators of cylinder bank 2 are
transmitted via private bus.

Engine Control Module

(ECM) J623

The slave control module acts as the misfire detector for
each of the eight cylinders. It also processes the signal
from the Engine Speed (RPM) Sensor G28.

Master and slave control modules are identical in design
and have the same part number. A voltage code in the
control module determines whether the control module
in the master or the slave.

If battery positive is applied to the encoding pin, the
control module is the master.

Engine Control Module

(ECM) 2 J624

Private Bus

CAN Data Bus

28

Notes

29

Transmissions/Driveline

Transmission and Driveline

The Audi R8 is equipped a 6-speed transmission (manual
or R-tronic) which delivers a torque output of up to 443
Lb-ft (600 Nm). Both transmissions use a double-disc dry
clutch. The clutch assembly (pressure plate and discs)
can only be replaced as a single unit due to balancing
and riveting. Clutch control has some variation between
the two transmission versions.

Viscous

Coupling

The difference between the two is the manual system
uses a clutch pedal, clutch master cylinder, and lines to
the slave cylinder; however, the R-tronic system uses
an electro-hydraulic unit (controlled by Transmission
Control Module J217) which replaces the clutch pedal
and the clutch master cylinder.

The R8 driveline includes a limited slip differential and a
viscous clutch.

Limited Slip

Differential

30

Transmission

Transmissions

Transmissions/Driveline

The manual and R-tronic units are fully synchronized 6­speed transmissions, are internally identical, and have a
torque output of up to 443 Lb-ft (600 Nm).

The gear oil of the transmission requires no regular
maintenance. Either transmission can be removed and
installed without removing the engine.

31

Transmissions/Driveline

Transmission Cooling System

The manual and R-tronic transmissions use a
thermostatically controlled cooling system. The system
is comprised of a pump, thermostat, and cooler.

Pump

Transmission cooling system capacity is 4.2 qt
(4.0L). Approximately 3.7 qt (3.5L) is circulated in the
transmission while 0.53 qt (0.5L) is in the cooler.

Cooler

32

Thermostat

Manual Shift

Transmissions/Driveline

On manual transmission vehicles, shifting is done
through a cable operated linkage system after pushing
the clutch pedal. As with all current Audi models
equipped with manual transmissions, the clutch pedal
must be depressed when starting the engine.

Manual Transmission Shift Gate

The shifter is connected to the transmission by two
Bowden cables. The length of the cables can be adjusted
by means of two quick-release fasteners. The cables are
spring loaded for easy length adjustment.

Spring Loaded

Cable Adjusters

33

Transmissions/Driveline

R-tronic Shift

The gears in the R-tronic transmission shift without
a mechanical connection to the selector lever.
Transmission Control Module (TCM) J217 drives electro­hydraulic valves inside a hydraulic unit according to the
signals received. The shift control selector lever has two
stable fixed-lock positions: left and right.

From the left position, the Automatic mode as well as
upshifting and downshifting can be selected by tapping
the lever accordingly (A, +, or -). From the right position,
reverse can be selected. In order to shift into reverse,
the engine should be at idle when at a stop with the
brake pedal pressed while tapping the lever to the R
position.

R-tronic Transmission Shift Control Selector

The transmission shifts into neutral whenever the lever
is moved from one fixed lock position to the other fixed
lock position.

The Sport function (S mode) is selected by pressing the
Sport button located next to the selector lever. Selecting
the S mode in the Audi R8 allows for even more sportily
tuned driving and shifting characteristics; shifting speed
is reduced, and the shifting point is set at a higher
engine speed range.

34

R-tronic Transmission

Transmissions/Driveline

Hydraulic

Unit

The R-tronic transmission has an electro-hydraulic
unit which is located on top and a pressure reservoir
and hydraulic pump which are on the right side. The
hydraulic unit contains four valves for shifting gears, two
gear detection sensors, and a pressure sensor. The gears
are shifted and the clutch is controlled by an electro­hydraulic system in the R-tronic. The system uses a
hydraulic circuit with a system pressure of 40 to 50 bar.

Pressure

Reservoir

A pump driven by an electric motor runs for a few
seconds after about three gear changes or after one
minute of idling. The pump is almost inaudible while the
engine is running. If the car has not been driven for a
long period of time and the system pressure has dropped
below 580 psi (40 bar), the transmission hydraulic pump
and the fuel pump automatically turn on when the
driver’s door is opened.

Hydraulic Pump

35

Transmissions/Driveline

Rear Differential

The mid-engine design of the R8 required a new quattro
drive concept. The transmission and rear differential are
mounted longitudinally behind the engine. Power flows
from the engine to the transmission through a double­disc dry clutch assembly. Power to the rear wheels is
delivered through an asymmetric limited slip differential.

The limited-slip differential helps optimize balanced
handling. The locking ratio is 25 percent during
acceleration and 45 percent while coasting. This design
helps avoid abrupt load reversal reactions which may
occur if the driver switches from accelerating to braking
during a cornering maneuver.

Asymmetric

Limited Slip

Rear Differential

36

Viscous Coupling

Transmissions/Driveline

Power to the front wheels is through a two-piece, center
bearing supported driveshaft. The driveshaft runs from
the transmission through the engine oil pan to the front
differential. From there, a viscous coupling distributes
power between the rear and front wheels.

The system was adapted to the mid-engine layout, with
its ideal axle load distribution of 44:56 percent. The
viscous coupling directs between 10 and 35 percent of
the engine power to the front wheels.

Front Differential

Drive Shaft

Center Bearing

Viscous

Coupling

Two Piece

Drive Shaft

37

Running Gear

Overview

The Audi R8 has four-link independent suspension at
both sets of wheels. High performance shock absorbers
contribute to the agile handling and sporty road
dynamics of the R8.

The anti-lock brake system incorporates electronic
brake-force distribution and hydraulic brake assist. The
R8 is equipped with large 8-piston fixed caliper brakes at
the front and 4-piston fixed-caliper brakes at the rear.

The Audi magnetic ride adaptive damping system allows
the suspension settings to be individually preconfigured
between Normal and Sport. The system benefits
include continuous damping, short response time, and
continuous real-time regulation.

Tire pressure changes are directly displayed in the
driver information system as part of the tire pressure
monitoring system. One sensor on each wheel
constantly monitors the tire pressure.

38

Front Axle

The front axle of the Audi R8 includes the following:

Running Gear

– Double Transverse Control Arm Axle.
– Steel Springs with Hydraulic Shock Absorbers.
– Hydraulic Rack and Pinion Steering.

– Alloy Wheels 8.5 J x 19.
– Tires 235/35.

Rear Axle

The rear axle includes the following:

– Double Transverse Control Arm Axle.
– Steel Springs with Hydraulic Shock Absorbers.

– Alloy Wheels 11 J x 19.
– Tires 295/30.

39

Running Gear

Brake System

Unique Components

Unique brake components for the Audi R8 include 8­piston, 4-pad front calipers; 4-piston, 2-pad rear calipers;
and separate mechanically activated parking brake
calipers.

Front Brake

Front and rear rotors are of a two-piece design and are
cross-drilled for ventilation. The Audi R8 has an ESP
wet braking feature: slight, intermittent disc movement
wipes off water from rotors.

40

Rear Brake

Audi Magnetic Ride

Running Gear

The Audi R8 utilizes “Audi magnetic ride,” a new semi­active suspension system with magneto-rheologically
controlled dampers. The sport mode can be activated
and deactivated at the touch of a button.

Dampening Adjustment

Button E387

Audi magnetic ride improves driving dynamics and
driving comfort for the following reasons:

– Reduced Body Movement (Pitch and Roll).
– Optimized Vibration Behavior.
– Optimized Road-Holding.
– Optimized Handling.

Electronic Damping

Control Module J250

Dampening Adjustment

Indicator Lamp K189

Reference

For details of the design and function
of the Audi Magnetic Ride, see The
2008 Audi TT Running Gear, Self-Study
Program 993703.

Dampening Adjustment

Valves N336 - N339

41

Running Gear

Tire Pressure Monitoring System

The Audi R8 uses a revised version of the system used
on the Audi A6. It is a direct pressure measuring system
with tire pressure sensors in the wheels.

J285

J533

Reference

For more detailed information about the
tire pressure monitoring system, see
The 2008 Audi TT Running Gear, Self­Study Program 993703.

J502

G222 G223 G225G224

J285 Instrument Cluster Control Module

J533 Data Bus On Board Diagnostic Interface

J502 Tire Pressure Monitoring Control Module

E492 Tire Pressure Monitoring Display Button

G222-225 Tire Pressure Monitoring Sensors

42

Instrument Cluster CAN

Powertrain CAN

Notes

43

Electrical

Topology and Networking

Engine Control

Module (ECM)

J623

Engine Control

Module 2

J624

Transmission

Control Module

J217

Selector Lever

Sensor System

Control Module J587

Airbag Control

Module J234

ABS Control

Module J104

ESP Sensor Unit

G419

Steering Angle

Sensor G85

Electronic Damping

Control Module J250

44

Steering

Column Electronic

Systems Control

Module J527

Multi-function

Steering Wheel

Control Module J453

CAN Drive

CAN Infotainment

CAN Comfort

CAN Combi

CAN Diagnostics CAN Bus

LIN Bus

Sub-Bus System

Panasonic Bus

Data Link

Connector

Electrical

Instrument Cluster

Control Module J285

Diagnostic Interface

For Data Bus J533

Driver’s Door

Control Module

Passenger’s Door

Control Module

Control Module

Control Module

J386

J387

Parking Aid

J446

Climatronic

J255

Fresh Air Blower

Control Module

J126

A/C

Pressure/Temperature

Sensor G395

Telephone

Transceiver

R36

Satellite Radio

R146

Digital Sound

System Control

Module J525

Radio

R

Radio/Navigation

Display Unit

Control Module J503

Comfort System

Central Control

Module J393

Vehicle Electrical

System Control

Module J519

Tire Pressure

Monitoring

Control Module

J502

Anti-Theft

Alarm Sensor

G578

Alarm Horn

H12

Wiper Motor

Control Module

J400

Rain/Light

Recognition Sensor

G397

CD Changer

R41

Passenger’s

Windshield Wiper

Motor Control

Module J584

45

Electrical

Battery

In the Audi R8, the battery is located at the front
in the luggage compartment, behind the luggage
compartment cover. The battery terminals are
accessible by removing the battery compartment cover.

To remove the battery, it is necessary to remove the
luggage compartment well cover and then the luggage
compartment well itself. The R8 does not have any
special jump start points.

46

Fuses and Relays

Fuse Locations Relay Locations

– 2 Main Fuse Panels (Right A-Pillar Footwell)
– Fuse Box (Passenger Footwell)
– Additional Fuse Panel (Under Right Rear Window Shelf)

Main Fuse Panel - SD

– Vehicle Electrical System Control Module
(Front Passenger Footwell)

– Additional Relay Panel (Right Rear Window Shelf)

Electrical

Fuse Box - B

Additional Fuse Panel - C

47

Electrical

Front Lights

The Audi R8 is equipped with Bi-xenon headlights.
Twelve LEDs run as daytime running lights or dimmed
as a navigation light. PWM dimming turns the daytime
running lights into a navigation light.

Indicator

A 24-watt filament bulb (P24W Silver Vision) is used for
the indicator light. To replace the bulb, it is necessary
to remove the headlight.

Main Beam and Low

Beam Headlights

Bi-xenon

48

Daytime Running Light

or Navigation Light

(Dimmed)

Rear Lights

Electrical

The tail lights, brake lights, and indicators of the Audi
R8 are equipped with LEDs. The tail lights use 40 LEDs.
The LEDs are lit more intensely during braking. (The
third brake light is an LED strip installed in the roof.)

Reverse

Light

The reverse light is equipped with a conventional 21­watt halogen lamp. The reverse lights can be replaced
when the tail light assembly has been removed.

Brake Light

Tail Light

Turn Signal

Tail Light

49

Electrical

Wiper System

The wiper system consists of two wiper motors with
integrated electronics.

Onboard supply control module J519 is part of the
Comfort CAN within the vehicle network. It takes over
the function of the LIN master for the control module
of wiper motor J400. This control module regulates the
wiper processes and controls front passenger side wiper
motor control module J584.

Data Line

The wiper control modules are integrated into the wiper
motors.

The wipers can be put into the service position using the
“Set” menu item in the extended comfort menu. This
position can also be used in winter when covering the
front window to protect it from icing up.

Passenger’s Windshield

Wiper Motor Control

Module J584

Vehicle Electrical System

Control Module J519

Wiper Motor

Control Module

J400

LIN

Rain/Light

Recognition Sensor

G397

50

Infotainment

Electrical

Standard Audi Sound 140W (5 channels)

- 4 loudspeakers in the doors

- 2 tweeters in a mirror triangle

- Center

Optional Bang & Olufsen Sound
465W (10 channels)

- 4 loudspeakers in the doors

- 2 tweeters in a mirror triangle

- 2 loudspeakers and 2 tweeters at rear

- Center

- Subwoofer

51

Electrical

Infotainment Antennas

1. Antenna Amplifier R112 / FM2

2. Satellite Antenna R170 / SDARS

3. Antenna for Radio and Telephone R51

4. Antenna Amplifier R24 / AM / FM1

5. Antenna Amplifier R111 / FZV

6. Control Device for Antenna Selection J515

7. Navigation Antenna R50

1

2

52

3

7

6

5

4

Notes

53

Air Conditioning

Overview

The Audi R8’s automatic air conditioning system is
configured as a single-zone air conditioning system.
The R8 has only one climate zone with no temperature
differential between the driver and passenger sides.

Climate Control Module J255 has a rotary knob for
temperature selection, but no digital display. The system
has an air recirculation function, which can be activated
either by the occupants or automatically as soon as the
“ON” conditions for air recirculation have been met.

54

Note

The Audi R8 does not have an Air Quality
Sensor G238.

Climatronic Control Module J255

Air Conditioning

The setpoint for the temperature flap is set using the
“Temperature” rotary knob. The rotary knob is infinitely
variable and activates the “Maximum Cool” function in
the lowest setting and the “Maximum Heat” function in
the highest setting.

Automatic mode of the air conditioning system can
be deactivated with the “Air Flow” or “Air Distribution”
rotary knob or by pressing the DEFROST or AC button.

The air conditioner compressor can be switched ON
or OFF by pressing the AC button. The system is active
without cooling function when the air conditioner
compressor is OFF.

Temperature

Rotary Knob

Defrost

Function Key

The seat heater is optional equipment with the Audi R8.
The three heater settings can be set by pressing the
function keys.

In setting 0 the seat heater is OFF. Setting 0 cannot
be selected directly from setting 3 — it can only be
activated by pressing the “Minus” key several times.

The function keys are backlit, with currently “active”
functions indicated by integrated LEDs. Instrument
Cluster Control Module J285 provides the dimming
signals terminal 58d for the function LEDs and terminal
58s for the key backlighting through the CAN bus.
The LEDs of the function buttons and the button
backlighting cannot be switched individually.

Rear Window

Air Flow

Rotary Knob

Defroster

Function Key

Air

Distribution

Rotary Knob

Left Seat Heater

Function Key

AUTO

Function Key

Air Recirculation

Function Key

AC Function Key

Right Seat

Heater Function

Key

55

Air Conditioning

System Communication

Various sensors provide input to Climatronic Control
Module J255. Outside Air Temperature Sensor G17 is
located in front of the condenser on the right side of the
vehicle. The sensor signal is evaluated by Instrument
Cluster Control Module J285. The signal is then sent
to other control modules, as well as Climatronic
Control Module J255 via the comfort CAN system. The
temperature value of the sensor is recalculated in
Climatronic Control Module J255 since the actual value
is not always measured due to the location of Outside
Air Temperature Sensor G17. Dash panel temperature
sensor G56 is received by Climatronic Control Module
J255, and the sensor is part of the module.

J533

Combi CAN

J285

Comfort CAN LIN Bus

Data is transferred between Fresh Air Blower Control
Module J126 and Climatronic Control Module J255 using
the LIN data bus system of the air conditioning system.
A/C Pressure/Temperature Sensor G395 also transfers
data to Climatronic Control Module J255 using the
LIN data bus. The following sensors use discrete wire
communication to Climatronic Control Module J255:
Fresh Air Intake Duct Temperature Sensor G89 (located
in the air intake unit), Sunlight Photo Sensor G107 (used
to take into account when actuators are operated), and
Seat Temperature Sensors G344 (left) and G345 (right).

G89

J255

G107

J126

G17

G344

G395

G345

56

Notes

57

Self-Study Programs

SSP 991703 - The 2008 Audi
TT Vehicle Introduction

– Body

– Occupant Protection

– Engine

– Suspension System

– Electrical System

– Air Conditioning

– Infotainment

SSP 993703 The 2008 Audi TT
Running Gear

– Axles

– Brake System

– Steering System

– Audi Magnetic Ride

– Other Features

SSP 994703 The 2008 Audi TT Body

– Audi Space Frame (ASF)

– Joining Techniques and
Production Processes

– Vehicle Safety Concept

– Dimensions

SSP 921603 - The Audi 4.2L V8 Engine

– Engine Mechanical

– Oil Circulation System

– Cooling System

– Air Circulation System

– Fuel System

– Exhaust System

-– Engine Management

58

Knowledge Assessment

An on-line Knowledge Assessment (exam) is available for this SSP.

The Knowledge Assessment may or may not be required for Certification.

You can find this Knowledge Assessment at:

www.accessaudi.com

From the accessaudi.com homepage:

Click on the “ACADEMY” Tab –
Click on the “Academy Site” Link –
Click on the ”CRC Certification” Link –

Knowledge Assessment

For assistance, please call:

Learning Management Center Headquarters

Audi Academy

1-877-AUDI-LMC (283-4562)

(8:00 a.m. to 8:00 p.m. EST)

iii

99B703

All rights reserved.
Technical specifications
subject to change without
notice.

Audi of America, Inc.
3800 Hamlin Road
Auburn Hills, Michigan 48326