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
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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.
Reference
The Self-R
Note
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.
Notes
ii
Introduction
Audi R8 Overview
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.
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.
Notes
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)
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)
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.
Body
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.
Notes
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.
10
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).
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.
12
–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.
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.
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.
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.
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:
Main features which are unique to the R8 engine include
the following systems:
– Fuel Straight Injection.
– Roller Cam Rocker Arms with Hydraulic Lifters.
– Chain Drives for Camshafts and Accessories.
– Variable Camshaft Adjustment for Intake and Exhaust
Camshafts.
– Dry Sump Lubrication.
– Crankcase Ventilation.
– Cooling.
– Air Intake.
– Exhaust.
4.2L V8 FSI Engine
14
Engine
4.2L V8 FSI Engine
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.
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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.
Cyclone in
the Oil Tank
Crankcase
Ventilation
Oil-Free
Blow-By
Gases
Crankcase
Ventilation
Oil Return Feed
16
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.
Engine
Oil System
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
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
Engine Oil
Circuit
Oil Pump
Oil Tank
Oil Cooler
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 Pan Screws
Oil Tank Screw
18
Engine
Cooling System
Coolant
Equalization
Tank
Auxiliary
Water Pump
Radiator, Right
Pump
Valve Unit
Coolant
Pump
Oil Cooler
Radiator, Center
Radiator, Left
Supply circuit
Return circuit
19
Engine
Air Intake
The air intake system of the R8 engine begins at both
the right and left sideblades.
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.
Audi R8 Intake System
Mass Air Flow
Sensors
Throttle
Valve Control
Modules
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 N290
Fuel Metering
Valve 2 N402
High-Pressure
Fuel Pump 1
High-Pressure
Fuel Pump 2
Low Fuel Pressure
Sensor G410
Leakage Line
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.
High Pressure
Low Pressure
Depressurized
22
Engine
Fuel Pressure Sensor G247
Fuel (Rail) 2
To Fuel Injectors N83 - N86
(Cylinders 5-8)
Pressure Limiting Valve (136 Bar)
Fuel (Rail) 1
Fuel Injectors N30 - N33
(Cylinders 1-4)
Return Line
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.
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.
Audi R8 Exhaust System
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
PowerTrain CAN
Data Bus
Engine Control
Module (ECM) J623
Engine Control
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
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
Throttle Valve Control Module J338
Throttle Drive (for Electronic Power Control (EPC)) G186
Coolant Circulation Pump Relay J151
After-Run Coolant Pump V51
Diagnostic
Connection
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.
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.
Most sensors are connected to the ECM.
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.
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
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.
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.
Viscous
Coupling
Limited Slip
Differential
Transmission
30
Transmissions/Driveline
Transmissions
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.
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
Pump
Thermostat
32
Transmissions/Driveline
Manual Shift
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.
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.
Manual Transmission Shift Gate
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
34
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.
Transmissions/Driveline
R-tronic Transmission
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
Hydraulic Pump
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.
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
Transmissions/Driveline
Viscous Coupling
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
Viscous
Coupling
Drive Shaft
Center Bearing
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.
38
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.
Running Gear
Front Axle
The front axle of the Audi R8 includes the following:
– 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 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.
Front Brake
Rear Brake
40
Running Gear
Audi Magnetic Ride
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
Dampening Adjustment
Valves N336 - N339
Reference
For details of the design and function
of the Audi Magnetic Ride, see The
2008 Audi TT Running Gear, Self-Study
Program 993703.
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.
Reference
For more detailed information about the
tire pressure monitoring system, see
The 2008 Audi TT Running Gear, SelfStudy Program 993703.
J285
J533
J502
G222
G223
J285
Instrument Cluster Control Module
J285
Instrument Cluster Control Module
J533 J533
Data BusData
On Board
Interface
Bus OnDiagnostic
Board Diagnostic
Interface
J502 J502
Tire Pressure
Monitoring
ControlControl
Module
Tire Pressure
Monitoring
Module
Tire Pressure
Monitoring
E492 E492
Tire Pressure
Monitoring
DisplayDisplay
ButtonButton
G222-225
Tire Pressure
Monitoring
Sensors
G222-225
Tire Pressure
Monitoring
Sensors
42
G224
G225
Instrument Cluster CAN
Powertrain CAN
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
Electronic Damping
Control Module J250
Airbag Control
Module J234
ABS Control
Module J104
ESP Sensor Unit
G419
Steering Angle
Sensor G85
Steering
Column Electronic
Systems Control
Module J527
Multi-function
Steering Wheel
Control Module J453
44
CAN Drive
CAN Diagnostics CAN Bus
CAN Infotainment
LIN Bus
CAN Comfort
Sub-Bus System
CAN Combi
Panasonic Bus
Electrical
Data Link
Connector
Instrument Cluster
Control Module J285
Telephone
Transceiver
R36
Diagnostic Interface
For Data Bus J533
Driver’s Door
Control Module
J386
Satellite Radio
R146
Passenger’s Door
Control Module
J387
Digital Sound
System Control
Module J525
Parking Aid
Control Module
J446
Fresh Air Blower
Control Module
J126
Radio
R
Climatronic
Control Module
J255
A/C
Pressure/Temperature
Sensor G395
Radio/Navigation
Display Unit
Control Module J503
Anti-Theft
Alarm Sensor
G578
Comfort System
Central Control
Module J393
Alarm Horn
H12
Vehicle Electrical
System Control
Module J519
Wiper Motor
Control Module
J400
Tire Pressure
Monitoring
Control Module
J502
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.
46
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.
Electrical
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)
– Vehicle Electrical System Control Module
(Front Passenger Footwell)
– Additional Relay Panel (Right Rear Window Shelf)
Main Fuse Panel - SD
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.
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.
Indicator
Main Beam and Low
Beam Headlights
Bi-xenon
Daytime Running Light
or Navigation Light
(Dimmed)
48
Electrical
Rear Lights
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.
The wiper control modules are integrated into the wiper
motors.
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.
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
Data Line
Wiper Motor
Control Module
J400
Vehicle Electrical System
Control Module J519
LIN
Rain/Light
Recognition Sensor
G397
50
Electrical
Infotainment
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
3
7
6
5
4
52
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.
Note
The Audi R8 does not have an Air Quality
Sensor G238.
54
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.
Air Conditioning
Climatronic Control Module J255
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
Left Seat Heater
Function Key
Defrost
Function Key
AUTO
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.
Air Flow
Rotary Knob
Rear Window
Defroster
Function Key
Air Recirculation
Function Key
AC Function Key
Air
Distribution
Rotary Knob
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.
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).
J533
G89
G107
Combi CAN
J126
J285
J255
Comfort CAN
LIN Bus
G395
G17
56
G344
G345
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
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
For assistance, please call:
Audi Academy
Learning Management Center Headquarters
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