Audi A4 Service Training

Self Study Programme 646

For internal use only

Audi A4 (Type8W)

Vehicle electrics and electronics

Audi

Service Training

The AudiA4(type8W) is the second representative of the MLBevo

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(Modular Longitudinal Platform evolution) after the
AudiQ7(type4M). A fully equipped AudiA4(type8W) has around
90control units on board, many of which exchange data with one
another. Such close co-operation would not be possible without an
entirely new electronics architecture compared with the
AudiA4(type8K) – especially when it comes to the driver assist­ance systems.

The new FlexRay bus system in the AudiA4 networks multiple
control units and ensures that data is transmitted extremely
quickly and securely. The key components are the engine, the
automatic gearbox, the central suspension control unit, the Elec­tronic Stability Control (ESC) system, the power steering control
unit, the Stop&Go adaptivecruisecontrol system including trac
jam assist, the video camera and the airbag control unit which
manages the safety systems.
There are further data networks in addition to the FlexRay bus.
CAN bus systems (CAN = controller area network) integrate the air
conditioning system and several assistance systems such as
Audisideassist and the surround cameras.

They also facilitate communication between the comfort/conven­ience control units, the infotainment modules and central display
and operating components such as the MMI and Audi virtual
cockpit.
So-called LIN buses (LIN = local interconnect network) comple­ment the CAN buses by serving less complex subscriber systems
such as the interior lighting.
The Bang&OlufsenSoundSystem with 3D sound uses a MOST bus
(MOST = media oriented systems transport). As in other Audi
models, the AudiA4 now also has aluminium high-current wires
with diameters of 16mm2, 35mm2 and 50mm2.
However, the AudiA4 is the first Audi to use aluminium wires with
diameters of 2.5mm2, 4mm2 and 6mm2. Thanks to these modifi­cations, the electronics in the new Audi mid-range models contrib­ute to a lightweight design. The weight of the vehicle in this area
has been reduced by 6 kg compared with the previous model.

Learning objectives of this self study programme:

Once you have completed this self study programme you will be
able to answer the following questions:

• Where are the fuse and relay panels located in the Audi A4?

• In what locations are electrical components fitted on the car?

• Which bus systems are used in the AudiA4?

• What are the tasks of the control units in the car?

646_002

• What are the versions of the exterior lighting, and how are
the individual light functions implemented?

• What are the changes with regard to headlight range adjust­ment and calibration of the Audi Matrix LED headlights?

2

Contents

Voltage supply

Car battery ___________________________________________________________________________________________________________________________________________________ 4
Jump start terminal _________________________________________________________________________________________________________________________________________ 5
Supply structure _____________________________________________________________________________________________________________________________________________ 6
Fuses and relays _____________________________________________________________________________________________________________________________________________ 7
Aluminium wires ____________________________________________________________________________________________________________________________________________ 8

Networking

Installation locations of the control units _______________________________________________________________________________________________________________ 10
Topology ____________________________________________________________________________________________________________________________________________________12
Bus systems used on the AudiA4 ________________________________________________________________________________________________________________________14

Control units

Brief descriptions __________________________________________________________________________________________________________________________________________ 16

Exterior lighting

Headlight variants _________________________________________________________________________________________________________________________________________ 42
Xenon headlight ____________________________________________________________________________________________________________________________________________ 44
LED headlight _______________________________________________________________________________________________________________________________________________46
Audi Matrix LED headlight ________________________________________________________________________________________________________________________________48
Dynamic turn signal function _____________________________________________________________________________________________________________________________50
Tail lights ____________________________________________________________________________________________________________________________________________________51
High-level brake lights / number plate lights ___________________________________________________________________________________________________________54

Audi drive select

Functional characteristics _________________________________________________________________________________________________________________________________ 56
Displays and operation ____________________________________________________________________________________________________________________________________ 56
Audi drive select function _________________________________________________________________________________________________________________________________57
Functional features ________________________________________________________________________________________________________________________________________57

Vehicle electronics

Interior lighting ____________________________________________________________________________________________________________________________________________58
Overhead module __________________________________________________________________________________________________________________________________________ 62
Anti-theft alarm ____________________________________________________________________________________________________________________________________________ 63
Central locking _____________________________________________________________________________________________________________________________________________ 64
Sensor-controlled luggage compartment release ______________________________________________________________________________________________________ 66
Garage door opener (HomeLink) _________________________________________________________________________________________________________________________68
Head-up display ____________________________________________________________________________________________________________________________________________70

Appendix

Self study programmes ____________________________________________________________________________________________________________________________________71

new automotive components or new technologies.

It is not a repair manual! Figures are given for explanatory purposes only and refer to the data valid at the
time of preparation of the SSP.
This content is not updated.

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

NoteThe self study programme teaches a basic understanding of the design and mode of operation of new models,

Reference

3

Voltage supply

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Car battery

The car battery in the AudiA4(type 8W) is housed centrally in the
spare wheel well. The main fuse panel and the battery isolation
igniter N253 are located at the positive terminal of the car battery.
In the event of a crash, N253 disconnects the main battery lead.

The battery monitoring control unit J367 is located at the negative
terminal of the car battery. This control unit, also known as the
battery data module (BDM), combines with the earth lead to form
a unit.

Battery monitor control unit
J367

Battery
A

Main fuse panel and battery
isolation igniter

The following car batteries are used in the Audi A4:

Standard batteries EFB battery AGM car batteries

95 Ah/450 A 79 Ah/420 A 58 Ah/340 A

110 Ah/520 A 93 Ah/520 A 68 Ah/380 A

75 Ah/420 A

92 Ah/520 A

105 Ah/580 A

EFB battery

An EFB (Enhanced Flooded Battery) battery is a heavy-duty wet-cell
battery. The positive plate inside the car battery is coated with an
additional polyester scrim which provides the active mass of the
car battery with additional stability on the plate. The deep-cycle
resistance of these car batteries is higher than that of conventional
batteries. An EFB battery is charged in exactly the same way as a
standard car battery.

AGM car battery

AGM (Absorbent Glass Mat) car batteries have a glass microfibre
material inside in which the electrolyte is held. In addition to
having higher deep-cycle resistance, the AGM car battery is noted
for its leak-proof design. This is of course very important for
installation of the battery inside the car. When charging, it is
important to follow the charger's operating instructions and, if
required, to program the charger for AGM car batteries.

N253

646_081

4

Jump start terminal

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The jump start terminal (positive terminal) is located in the engine
bay on the right-hand side of the vehicle, adjacent to the air filter
box, under the red plastic cover. The earthing stud (negative
terminal) is connected directly to the body fore of the right suspen­sion strut tower.

Distributor for term. 30
TV2
with fuses

These terminals should also be used for charging the car battery in
the showroom or for diagnostics in the workshop.

Jump start terminal

Terminal 30 supply

Distributor supply line

Interference suppression capacitor
C24

Sealing cap

Earthing stud

Distributor 2 for term. 30
TV22

Starter/alternator cable

Connection to radiator fan control unit J293
(4-cylinder engines)

Connection to automatic glow period control unit J179 or
secondary air pump relay J299

Connection to radiator fan control unit 2 J671

Connection to radiator fan control unit J293

The actual jump start terminal is on the terminal 30 distributor
TV22 to which the interference suppression capacitor C24 is also
attached. The red 70-mm2 cable supplies the distributor. The
3fuses on the distributor for term. 30 TV2 protect the radiator
fan, the glow plugs and the secondary air pump.

646_082

2

The black 70 mm

wire leads from distributor 2 for term. 30 TV22
to the starter. A further wire leads from here to the three-phase
ACmotor. In 4-cylinder models, the power supply of the radiator
fan control unit J293 is located adjacent to the wire leading to the
starter/3-phase AC motor.

5

Supply structure

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The following diagram summarises the supply structure of the
AudiA4. This is a schematic diagram.

SC

SB

For exact details of fuse assignment and the cable routing, please
refer to the applicable service literature.

TV22

TV2

TV1

SF

Key:

1 Connection to auxiliary air heater stage 1
2 Connection to auxiliary air heater stages 2+3
3 Connection to radiator fan control unit J293

(4-cylinder engines)

4 Connection to automatic glow period control unit J179 or

secondary air pump relay J299

5 Connection to radiator fan control unit 2 J671
6 Connection to radiator fan control unit J293

A Battery
B Starter motor
C Alternator

Main fuse panel

646_083

J367 Battery monitor control unit
J500 Power steering control unit
N253 Battery isolation igniter
SB Fuse panel B, on the footrest
SC Fuse panel C, on the dash panel
SF Fuse panel F, in luggage compartment on L/H side
TV1 Fuse and relay box at base of right A-post
TV2 Distributor for term. 30
TV22 Distributor 2 for term. 30

6

Fuses and relays

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The fuses on the main fuse panel as well as distributors TV1 and
TV22 are labelled only "S" in the current flow diagram. This also
applies to other individual fuses distributed throughout the car.

Relay and fuse panel in
plenum chamber

Distributor for term. 30 TV2 and
distributor 2 for term. 30 TV22
with fuses

Fuses "SB", "SC" and "SF" can also be accessed by the driver on the
relevant fuse panels and therefore are also described in the
Owner's Manual.

Distributor for term. 30 TV1
with fuses

Main battery lead

Fuse panel C on the dash
panel, driver side.
The fuses here are labelled
"SC" in the current flow
diagram.

Fuse panel B on the driver
side footrest.
The fuses here are labelled
"SB" in the current flow
diagram.

Fuse panel F in the luggage
compartment, rear left.
The fuses here are labelled
"SF" in the current flow
diagram.

Main fuse panel at
positive terminal of
car battery

646_084

Battery monitor control
unit at negative terminal
of car battery

7

Aluminium wires

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Main battery lead

Audi has been using aluminium electrical wires for some time now.
The AudiA4(type8W) makes no exception. The battery main lead
in the AudiA4 is made of aluminium, like the AudiA8(type4H)
where this was used for the first time. This lead begins at the main
fuse panel as a flexible round cable. On the right hand-side of the
luggage compartment well, it is welded onto a flexurally rigid
aluminium ribbon cable.

Wiring harness

A new feature of Audi vehicles, beginning with the
AudiA4(type8W), is the use of aluminium wires with diameters of

2.5mm2, 4mm2 and 6mm2 in certain areas of the wiring harness.

Repairing aluminium wires

A new tool was developed for the repair of aluminium wires –the
wires harness repair kit for aluminium wires VAS631001.
In addition to a crimping pliers, this repair kit includes a wire
stripper and a special crimp connector including heat shrink tubing
for wire diameters of 2.5mm2, 4mm2 and 6mm2.

This ribbon cable runs along the right-hand side of the vehicle
through the rear section of the vehicle and under the rear seat,
terminating in the heel panel area. Here it is welded onto a round
cable which continues along the inside of the right-hand sill and
through the engine bulkhead to the jump starting terminal in the
engine bay.
If faulty, the aluminium main battery lead can only be replaced
completely. There is no provision for repair work.

This helps save weight in the electrical system. Copper wires with
diameters from 1.5mm
areas in which wires are subject to movement, e.g. on the bonnet.

As before, copper wires can be repaired using the wiring harness
repair kit VAS1978B. Cut wires can be reconnected using crimp
connectors. Repair wires with industrial manufactured contacts are
also available.

2

to 6mm2 are also used, particularly in

Crimping pliers

Wire stripper

Heat shrink tubing

646_087

Crimp connector

8

Special crimp connectors are used for the repair of aluminium

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wires. These connectors ensure strain resistant connection of the
aluminium wires. The supplied heat shrink tubing reliably protects
the joints against moisture.

Transition zone Insulation fitting

A cut aluminium wire can be reconnected using this crimp connec­tor. If it is necessary to attach a new section of wires, the copper
repair wires from repair kit VAS 1978A can be used.

Wire crimping sleeve
with serrations and additive

Coding for wire diameter in crimping pliers

Challenges in repairing aluminium wires:

1. The crimp connector must provide a strain resistant connec­tion.

To achieve a strain resistant connection with the aluminium wires,
the oxide layers on the individual strands of the aluminium wires
must be broken. This is achieved by the serrations in the crimp
connectors. These serrations are also coated with an additive to
provide better corrosion protection.

Oxide layer

Code for wire diameter
(both sides)

646_088

2. The joint must be sealed.

As copper repair wires are used, there is an aluminium wire on one
side of the connector and a copper wire on the other side. To
prevent electrochemical corrosion, the joint must be reliably
protected against corrosion. The heat shrink tubing supplied with
the crimp connector is used for this purpose.

Heat shrink tubing

Cable strand

646_089

Oxide layer broken by
serrations in connector

Heat shrink tubing
(heat shrunk)

Reference

For a detailed description of how to repair aluminium wires, please refer to the Workshop Manual.

646_090

9

Networking

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Installation locations of the control units

Some of the control units shown in the overview are optional and/
or country-specific equipment.
For the sake of clarity, not all control units fitted in the vehicle can
be shown here.

J428

J364

J1023

A27

Refer to the current service literature for details of control unit
installation positions as well as instructions for installation and
removal.

J794

J217J500

J685

E87

J844

R242

J387

E380

J245

J587

J623

A31 J104

J1018

J850

Key:

A27 Right LED headlight power module 1
A31 Left LED headlight power module 1

E87 Front air conditioner/Climatronic operating and display unit
E265 Rear air conditioner/Climatronic operating and display unit
E380 Multimedia system operating unit

J104 ABS control unit
J136 Seat and steering column adjustment control unit with

memory

J217 Automatic gearbox control unit
J234 Airbag control unit
J245 Sliding sunroof control unit
J285 Instrument panel control unit

J764

J898

J519

J285

J527

J792

J386

J345 Trailer detector control unit
J364 Auxiliary heating control unit
J386 Driver side door control unit
J387 Front pass. side door control unit
J393 Central control unit for comfort/convenience system
J428 ACC control unit
J492 All-wheel drive control unit
J500 Power steering control unit
J519 Electrical system control unit
J521 Control unit for pass. seat adjustment with memory function
J525 Digital sound package control unit
J527 Steering column electronics control unit
J533 Data bus diagnostic interface
J587 Selector lever sensors control unit

10

J649

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J521

J927

R78

J769

J880

J492

J234

J775

J136

J648

J605 Rear hatch control unit
J608 Control unit for special vehicles
J623 Engine control unit
J648 Control unit for rear left information display and operating

unit

J649 Control unit for rear right information display and operating

unit

J685 MMI display
J764 Electrical steering column lock control unit
J769 Audi lane assist control unit
J770 Audi lane assist control unit 2
J772 Rear-view camera system control unit
J775 Suspension control unit
J792 Control unit for active steering

E265

J926

J533

J605

J525

J928

J608

J345

J393

J770

J772

J794 Information electronics control unit 1
J844 Main beam assist control unit
J850 ACC control unit 2
J880 Reducing agent metering system control unit
J898 Control unit for windscreen projection J898 (head-up display)
J926 Door control unit, rear driver side
J927 Door control unit, rear pass. side
J928 Surround camera control unit
J1018 Control unit for light control, left
J1018 Control unit for light control, right

R78 TV tuner
R242 Front camera for driver assistance systems

646_010

11

Topology

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The topology shows all control units with connectivity to the bus
systems.

Door control unit,
rear driver side
J926

Door control unit,
rear pass. side
J927

Flap control control
motors
1 –15

Driver side door
control unit
J386

Front pass. side
door control unit
J387

Seat and steering
column adjustment
control unit with
memory function
J136

Front air conditioner/Climatronic operating and display
unit
E87

Fresh air blower
control unit
J126

High pressure
sender
G65

Rear air conditioner/Climatronic operating and display
unit
E265

Electronic steering
column lock
control unit
J764

Some of the control units shown here are optional or country­specific equipment or are scheduled for rollout at a later date.

Humidity sensor in
fresh air intake
duct
G657

Air quality sensor
G238

Diagnostic port

Front pass. seat
adjustment control
unit with memory
J521

Special vehicle
control unit
J608

Sliding sunroof
control unit
J245

Rear hatch
control unit
J605

Heated windscreen
control unit
J505

Anti-theft alarm
sensor
G578

Trailer detector
control unit
J345

Alarm horn
H12

Data bus diagnostic interface
J533

Seat back fan 1,
front left
V512

Seat cushion fan 1,
front left
V514

Seat back fan 1,
front right
V516

Seat cushion fan 1,
front right
V518

Electrical system control unit
J519

Rear hatch
power opening
control unit
J938

Garage door
operating unit
E284

Garage door opener
control unit
J530

Automatic anti daz­zle rear view mirror
Y7

Roof electronics
control unit
J528

Interior light
module

Light switch
E1

Wiper motor
control unit
J400

Rain and light
detector sensor
G397

Humidity sensor
G355

Interior light
module

Central control unit for comfort/convenience system
J393

Key:

Convenience CAN

Hybrid CAN

Extended CAN

Infotainment CAN

12

Diagnostics CAN

FlexRay

Modular Infotainment Platform (MIB) CAN

LIN bus

For presentation reasons, the FlexRay topology does not mirror the

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actual configuration of the control units. This also applies to the
control units connected to the MOST bus.

Multifunction
steering wheel
control unit
J453

L/H control unit for
light control
J1018

Driver side volume
control
E67

Multimedia system
key module
E817

Battery monitor
control unit
J367

Alternator
C

Front camera for
driver assistance
systems
R242

Control unit for
rear left informa­tion display and
operating unit
J648

Control unit for
rear right informa­tion display and
operating unit
J649

Multimedia system
operating unit
E380

MMI display
J685

Selector lever sen­sors control unit
J587

Engine control unit
J623

Digital sound
package
control unit
J525

Information
electronics
control unit1
J794

sender

NO

x

control unit
J583

TV tuner
R78

Control unit in dash
panel insert
J285

Control unit for
windscreen
projection
(head-up display)
J898

Surround camera
control unit
J928

or

Rear-view camera
system control unit
J772

R/H control unit for
light control
J1023

ABS control unit
J104

Left LED headlight
power module1
A31

Right LED headlight
power module1
A27

Operating unit 1 for
drive and comfort/
convenience func­tions E791

Power steering
control unit
J500

Suspension control
unit
J775

Steering column
electronics
control unit
J527

ACC control unit
J428

All-wheel drive
control unit
J492

Radiator louvre
control motor
V544

Radiator louvre
control motor 2
V550

Active steering
control unit
J792

Airbag
control unit
J234

ACC control unit 2
J850

Automatic gearbox
control unit
J217

NO

sender

x

control unit 2
J881

Particulate sensor
G784

Front left seat
belt tensioner
control unit
J854

Front right seat
belt tensioner
control unit
J855

Seat occupancy
recognition
control unit
J706

Electrical pump2
for gearbox
V553

Reducing agent
metering system
control unit
J880

Main beam assist
control unit
J844

Audi side assist
control unit
J769

Audi side assist
control unit 2
J770

Auxiliary heating
control unit
J364

Remote control
receiver for auxil­iary heating
R64

646_003

Sub-bus systems

MOST bus

LVDS

FBAS

"OR" configuration

Ethernet port for diagnose interface VAS6154

13

Bus systems used on the AudiA4

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Bus system Cable

colour

Conguration Max. data

transfer rate

Property

Hybrid CAN Electrical two-wire bus system 500kbit/s not single wire capable

Convenience CAN Electrical two-wire bus system 500kbit/s not single wire capable

Extended CAN Electrical two-wire bus system 500kbit/s not single wire capable

Infotainment CAN Electrical two-wire bus system 500kbit/s not single wire capable

Modular Infotainment

Electrical two-wire bus system 500kbit/s not single wire capable

Platform (MIB) CAN

Diagnostics CAN Electrical two-wire bus system 500kbit/s not single wire capable

FlexRay Electrical two-wire bus system 10Mbit/s not single wire capable

MOST bus Fibre-optic bus system 150Mbit/s Ring structure:

an open circuit will
result in total system
failure

LIN bus Electrical single-wire bus system 20kbit/s single wire capable

Sub-bus system Electrical two-wire bus system 500kbit/s not single wire capable

LVDS Electrical two-wire bus system approx. 200 Mbit/s not single wire capable

FBAS Electrical single-wire bus system approx. 80 Mbit/s single wire capable

The network diagram on page12 provides a schematic overview of
the communication paths between the control units in the Audi
A4. As a further member of the MLBevo family, the
AudiA4(type8W) cannot deny its close anity to the
AudiQ7(type4M) in the area of control unit networking. The bus
systems used in the AudiA4 are identical to those of the
AudiQ7(type4M).

Infotainment topology

In the AudiA4 up to 4control units are integrated in the MOST ring
in the following order:

• Information electronics control unit 1 J794

• Control unit in dash panel insert J285

• TV tuner R78

• Digital sound package control unit J525

If we compare this with the AudiQ7(type4M), the dierence is
that the DVD changer is absent from the MOST ring in the Audi A4.
Volume control E67 is configured as the LIN slave on the control
panel E380. In models with manual gearbox, the operator control
module for multimedia system E817 is additionally connected.
Control units J648 and J649 have been added to the MIB CAN and
will be also be featured in the AudiQ7(type4M) after the launch
of the AudiA4.

Key:

Infotainment CAN
Modular Infotainment Platform (MIB) CAN
LIN bus
MOST bus

If we compare the AudiA4(type8W) with the AudiA4(Typ8K),
new features in the area of data transmission are the FlexRay,
MOST150 and LVDS buses.
In spite of the many similarities with the AudiQ7(type4M), there
are a few dierences that are not exclusively equipment-specific.
For this reason, the topologies in the areas of infotainment and
FlexRay are described below.

R78

J285

J898J587

or

J772

646_051

E67

E817

LVDS

J648

J649

E380

J685

J525

J794

J533 J928

FBAS
Ring break diagnostics line
"OR" configuration

Reference

For further information and general descriptions of the MOST150 and FlexRay buses, refer to Self Study Programme634
"AudiQ7 (type4M) Onboard Power Supply and Networking".

14

FlexRay topology

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The data bus diagnostic interface J533 is the controller for the
FlexRay bus. All FlexRay control units are connected to J533 via
various branches. In this configuration J533 is referred to as the
"active hub" or "active node". If only one control unit is connected
to a branch, this is referred to as a "point to point" connection.

ABS
control unit
J104

Engine
control unit
J623

Data bus diagnostic interface
J533

Branch4

Power steering
control unit
J500

Automatic gear­box control unit
J217

ACC
control unit2
J850

A configuration in which more than one control unit is connected
to a branch is known as a "daisy chain connection".
In the AudiA4 six branches are used: branches 1–5 and branch 8.
The pins of branches 6 and 7 are reserved in the current version of
J533, but are still not assigned.
The following figure is a schematic diagram showing how the
control units are connected.

Steering column
electronics
control unit
J527

Front camera for
driver assistance
systems
R242

Suspension
control unit
J775

Branch3Branch2Branch1

Branch8Branch5

Active steering
control unit
J792

Airbag
control unit
J234

ACC control unit
J428

The next figure shows the actual situation. In configuring of the
control units, a distinction is made between the bus positive cable
(pink) and the bus negative cable (green).
Two resistors each having a resistance of 47Ω (94Ω in total) are
always connected at the beginning and end of a branch. Each of
the so-called "centre control units" has two resistors with a resist-

ance of 1.3Ω, i.e. 2.6 Ω in total.

J104

1.3kΩ 1.3kΩ

J500

47Ω47Ω47Ω47Ω 47Ω47Ω

J217

1.3kΩ 1.3kΩ

All-wheel drive
control unit
J492

646_052

A control unit from the vehicle's standard specification is always
connected at the end of a branch. This ensures that there is a
resistance of 94 Ω at the end of each branch. Two optional control
units, which are integrated in other models as "centre control
units", are connected to branch 8 in the AudiA4. The FlexRay line
is, therefore, routed back to the data bus diagnostic interface
J533. The resistance here is 94 Ω - the value required for the
termination of branch 8.

J527

R242J623

1.3kΩ 1.3kΩ

J775

1.3kΩ 1.3kΩ

47Ω 47Ω

47Ω 47Ω

J533

Branch4

47Ω

47Ω 47Ω 47Ω

47Ω 47Ω

47Ω 47Ω 47Ω 47Ω

1.3kΩ 1.3kΩ

J850

J428 J492J234

Branch3Branch2Branch1

47Ω 47Ω

47Ω 47Ω

Branch8Branch5

1.3kΩ 1.3kΩ

J792

1.3kΩ 1.3kΩ

646_053

15

Control units

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Ξ Contents

Brief descriptions

Electrical system control unit

Connector C (54-pin)
to cockpit wiring harness

646_012

Connectors A and B (each 73-pin)
to vehicle / engine bay

16

Designation Electrical system control unit J519 /

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Ξ Contents

also referred to as BCM1 (Body Control Module 1)

Equipment Always fitted

Installation location On A post, L/H side, above bonnet release lever

(installation location is always on the L/H side, even in RHD models)

Tasks Exterior lighting master

Interior lighting master

Diagnostic gateway for the light control units

A/C functions

• Activation of seat heater and front seat ventilation

• Activation of air conditioning compressor without regulating valve N280 and solenoid cou-

pling for air conditioning system N25

Integration functions

• Parking

• Parking aid

• Park assist steering

• Activation of front and rear acoustic signal generators

• Ambient lighting

• Activation and supply of LIN interior light modules

• Headlight range adjustment

• Calculation of headlight range adjustment

• Activation of headlight range adjustment via the left and right control units for light

control J1018 and J1023.

• Read-in of the signals from the inclination sensor via the CAN line

Other functions

• Reading (senders/sensors/switches)

• Ambient temperature

• New engine coolant, windscreen washer fluid, brake fluid

• Brake pad wear

• Bonnet contact

• Seater heater temperature

• Activation (actuators/control elements)

• Relay for sockets

• Signal horn

• Headlight washer system

• Windscreen washer pump (dual pump)

• Heating the windscreen washer jets

Diagnostic address 09

• Seat heater, front

Data bus communication • Convenience CAN subscribers

• J519 is the LIN master for

• LIN 1: Light switch E1, wiper motor control unit J400, combined sensor – rain and light

detection sensor G397 and humidity sensor G355

• LIN 2: Garage door operating unitE284, garage door operation control unitJ530, auto­matic anti dazzle rear view mirror Y7, roof electronics control unitJ528

• LIN 3: Front left seat back fan 1 V512, front left seat cushion fan V514, front right seat
back fan 1 V516, front right seat cushion fan V518

• LIN 4: Operating unit 1 for drive and comfort/convenience functions E791

• LIN 5: Interior light module

• LIN 6: Interior light module

• Communicates via a sub-bus system with the L/H and R/H control units for light control

J1018 andJ1023 and left and right LED headlight power modules 1 A31 and A27

Special feature Fault finding notes:

J519 has duplicated pins at the LIN slave connection. For example, LIN1 is distributed to
3pins (A22, A23,C50), which, however, are connected internally within the control unit. This
means that the control units connected to pin A23 and C50 are also aected in the event of a
short circuit to positive or negative at pin A22 and vice versa.

17

Gateway

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Designation Data bus diagnostic interface J533

Equipment Always fitted

Installation location Under the rear seat, on the floor pan

Tasks • Network system gateway

• Controller for FlexRay bus

• Diagnostic master

• Energy management control unit

• Interface for various connect services

Diagnostic address 19

Data bus communication • Hybrid CAN, convenience CAN, Infotainment CAN, CAN-Extended and FlexRay user

• LIN master of battery monitor control unit J367 and alternator C

• LIN master for multifunction steering wheel control unit J453

Special features • Not a user of the Modular Infotainment Platform (MIB) CAN

• Not a user of the MOST bus

• Additional variant as "connected gateway"

1)

646_011

Data bus diagnostic interface
J533

1)

Optional equipment

18

Central control unit for comfort/convenience system

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Ξ Contents

Designation Central control unit for comfort/convenience system J393 /

also referred to as BCM2 (Body Control Module 2)

Equipment Always fitted

Installation location In luggage compartment on L/H side, behind luggage compartment side trim, under fuse and

relay panel
(installation location is always on L/H side, even in RHD models)

Tasks Central locking system master

Integration functions

• Terminal management system

• Entry and start authorisation

• Immobiliser (master)

• Anti-theft alarm system

Other functions

• Reading (senders/sensors/switches)

• Brake light switch

• Ignition starter button

• P signal

• Soft touch button on rear hatch

• Rear hatch contacts (prelock and full lock)

• Rear window breakage sensor

• Capacitive sensors of door handles

• Entry and start authorisation aerials

• Fuel tank sender

• Inclination sensors for headlight range adjustment

• Hall eect sensor, rear roller blind

• Activation (actuators/control elements)

• Rear hatch lock motor

• Luggage compartment release

• Fuel tank flap lock

• Rear roller blind motor (Avant only)

• Terminal 15 relay

• Heated rear window relay

• Rear wiper motor (Avant only)

• Supply voltage, rear hatch power opening control unit

• Luggage compartment lights

• Rear lighting

Diagnostic address 46

Data bus communication • Convenience CAN subscribers

• J393 is the LIN master for:

• LIN 1: Control unit for windscreen heater J505, antitheft alarm system sensorG578

• LIN 2: Alarm horn H12

• LIN 3: Rear hatch power opening control unit J938

Special features • J393 is the immobiliser system master in the AudiA4

• Central locking aerial is integrated in the control unit PCB

Central control unit for comfort/convenience system
J393

646_013

19

Door control unit

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Designation Driver side door control unit J386

Equipment Always fitted

Installation location In driver's door

Tasks Controlling the electrical and electronic components in and on the driver's door

• Reading (senders/sensors/switches)

• Switches/buttons, e.g. for window lifters, rear hatch release, electrical child lock

button, electrical door mirror, central locking, seat memory etc.

• Activation (actuators/control elements)

• Lights and components in and on the door trim, locking and safe motor, turn signals in

door mirror

Diagnostic address 42

Data bus communication • Convenience CAN subscribers

• LIN master for door control unit, rear driver side J926

Special feature The door control unit, rear driver side J926 has its own address code "BB" although it is a LIN

slave of J386.

Driver side door control unit
J386

Designation Front passenger side door control unit J387

Equipment Always fitted

Installation location In front passenger's door

Tasks Controlling the electrical and electronic components in and on the front passenger's door

• Reading (senders/sensors/switches)

• Switches/buttons, e.g. for window lifters, rear hatch release, electrical child lock

button, electrical door mirror, central locking, seat memory etc.

• Activation (actuators/control elements)

• Lights and components in and on the door trim, locking and safe motor, turn signals in

door mirror

Diagnostic address 52

646_014

Data bus communication • Convenience CAN subscribers

• LIN master for door control unit, rear passenger side J927

Special feature The door control unit, rear passenger side J927 has its own address code "BC" although it is a

LIN slave of J387.

20

Seat adjustment

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Designation Seat and steering column adjustment control unit with memory J136

Equipment Optional equipment (PR no.: PV3)

Installation location Below the driver's seat

Tasks Activation (actuators/control elements)

• Seat adjustment (memory function)

Diagnostic address 36

Data bus communication Convenience CAN subscribers

Special feature Contrary to what the name of the control unit in the "mummy list" would suggest, an electri-

cal steering wheel lock is not available in the Audi A4.

Seat and steering column adjustment control unit
with memory function
J136

Designation Control unit for passenger seat adjustment with memory function

J521

Equipment Optional equipment (PR no.: PV3)

Installation location Below the front passenger seat (not shown)

Tasks Activation (actuators/control elements)

• Seat adjustment (memory function)

Diagnostic address 06

Data bus communication Convenience CAN subscribers

646_015

21

Trailer detector

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Designation Trailer detector control unit J345

Equipment Optional equipment (PR no.: 1D9)

Installation location In luggage compartment, L/H side, behind luggage compartment side trim

Tasks Interconnects the in-car electrics and the trailer electrics

• Reading (senders/sensors/switches)

• Brake light switch

• Tow bar release button

• Activation (actuators/control elements)

• Tow bar warning lamp

• Tow bar lowering motor

Diagnostic address 69

Data bus communication Convenience CAN subscribers

Special feature Although the tow bar can be unlocked via a switch in the left luggage compartment trim, it

must be moved into its end position by hand until it audibly engages.

Trailer detector control unit
J345

Steering column lock control unit

Designation Electronic steering column lock control unit J764

Equipment • Always installed in vehicles with a manual gearbox

• In the case of vehicles with an automatic gearbox, installation is country-dependent

Installation location On steering column

Task Locking and unlocking the steering column

Diagnostic address 2B

Data bus communication Convenience CAN subscribers

Special features • Immobiliser user

• Can be replaced separately from the steering column

646_016

Electronic steering column lock control unit
J764

646_017

22

Sliding sunroof control unit

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Designation Sliding sunroof control unit J245

Equipment Optional equipment (PR no.: 3FU)

Installation location On sliding sunroof frame at front

Tasks Controlling the functions of the panoramic glass sunroof

• Reading (senders/sensors/switches)

• Controller for sliding sunroof adjustment

• Activation (actuators/control elements)

• Motors for sliding sunroof V1 and sliding sunroof roller blindV260

Diagnostic address CA

Data bus communication Convenience CAN subscribers

Sliding sunroof control unit
J245

Rear hatch control unit

Designation Rear hatch control unit J605

Equipment For Avant only

Installation location On roof cross member, rear centre

Tasks Controlling the functions of the electrical rear hatch

• Reading (senders/sensors/switches)

• Button for closing the rear hatch

• Activation (actuators/control elements)

• Rear hatch drive motors

• Luggage compartment cover motor

Diagnostic address 6D

Data bus communication Convenience CAN subscribers

Special feature The rear hatch control unit activates the rear parking aid speaker.

1)

646_018

1)

Optional "electrical luggage compartment cover" (PR no.: PKC)

Rear hatch control unit
J605

646_019

23

Interface control unit

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Designation Special vehicle control unit J608

Equipment Optional equipment (PR no.: e.g.: F4X paramedic version, F4G police version etc.)

Installation location In luggage compartment, L/H side, behind luggage compartment side trim

Task J608 serves as an interface between special installations, e.g.for paramedics, police, fire

service etc., and the vehicle electrics

Diagnostic address 3D

Data bus communication Convenience CAN subscribers

Special vehicle control unit
J608

Instrument cluster

Designation Control unit in dash panel insert J285

Equipment • Always fitted

Installation location In dash panel

Task Display of information relevant to the driver

Diagnostic address 17

Data bus communication • Infotainment CAN bus user

Special feature The instrument cluster in the AudiA4 is not integrated in the immobiliser.

• Optional Audivirtual cockpit (PR no.: 9S8)

• MOST subscriber

• Connected by LVDS bus to information electronics control unit 1 J794 (image transfer for

navigation display in instrument cluster).

646_085

24

Control unit in dash panel insert
J285

646_020

646_086

Control unit in dash panel insert
J285
(Audivitualcockpit)

ACC adaptive cruise control

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Designation ACC control unit J428

Equipment Optional equipment:

• ACC with Stop&Go including trac jam assist (PR no.: 8T8)

• ACC distance indicator (PR no.: 8T3)

Installation location On lock carrier, front right, behind front bumper cover

Tasks • Radar scanning of trac (distance and speed)

• Controlling speed and distance

• Distance display and distance warnings (only if ACC is deactivated)

Diagnostic address 13

Data bus communication FlexRay subscriber

Special features • ACC Stop&Go with integrated trac jam assistant

• Distance display and distance warning – display of distance in instrument cluster in seconds

• Function master for ACC control unit 2 J850

ACC control unit
J428

Designation ACC control unit 2 J850

Equipment Optional equipment

Installation location On lock carrier, front left, behind front bumper cover

Task Radar scanning of trac (distance and speed)

Diagnostic address 8B

Data bus communication FlexRay subscriber

Special feature ACC control unit 2 is a slave of the ACC control unit J428 and, based on its function, could also

be referred to as a sensor.

ACC control unit 2
J850

646_021

25

Main beam assist

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Designation Main beam assist control unit J844

Equipment Optional equipment (PR no.: 8G1)

Installation location In rear view mirror

Task Automatic activation and deactivation of main beam in response to oncoming trac

Diagnostic address 20

Data bus communication Extended CAN subscriber

Special features • J844 can only change over the dipped/main beam headlights. The front camera for driver

assistance systems R242 is required for Audi matrixLED headlights.

• Only installed if the customer has ordered main beam assist without further assistance
systems, such as Audi active Lane Assist or trac sign recognition.

Main beam assist control unit
J844

Front camera

Designation Front camera for driver assistance systems R242

Equipment Optional equipment

Installation location On windscreen above base of rear view mirror

Tasks Imaging of trac, trac signs and lane markers for

Diagnostic address A5

Data bus communication • FlexRay subscriber

Special features • Forms a functional unit in combination with image processing control unit

• Audi active lane assist (lane departure warning system)

• Main beam assist

• Road sign recognition

• ACC Stop&Go

• Audi pre sense

• Evasion assist

• Matrix Beam headlight

• R242 is connected to the light control units via a sub-bus system.

• The Audi MatrixLED headlights are also calibrated using the front camera for driver assist-

ance systems R242.

646_022

Front camera for driver assistance systems
R242

646_023

26

Automatic gearbox

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Designation Automatic gearbox control unit J217

Equipment Installed in combination with:

• 7-speed dual clutch gearbox 0CK/0CL – Stronic (PR no.: G1C/G1D)

• 8-speed automatic gearbox 0D5 – tiptronic (PR no.: G1G)

Installation location Component part of mechatronic unitJ743 of automatic gearbox

Task Controlling and monitoring the engagement and disengagement operations of the automatic

gearbox

Diagnostic address 02

Data bus communication • FlexRay subscriber

• LIN master for electrical pump2 for gearboxV553 (in conjunction with 7-speed Stronic)

Special feature Immobiliser user

Automatic gearbox control unit
J217
(7-speed dual clutch gearbox 0CK/0CL)

646_047

Automatic gearbox control unit
J217
(8-speed automatic gearbox 0D5)

646_024

Reference

For further information about the automatic gearboxes, refer to Self Study Programme644 "AudiA4 (type8W)".

27

Selector mechanism

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Designation Selector lever sensors control unit J587

Equipment Installed in combination with:

• 7-speed dual clutch gearbox 0CK/0CL – Stronic (PR no.: G1C/G1D)

• 8-speed automatic gearbox 0D5 – tiptronic (PR no.: G1G)

Installation location Within the selector mechanism

Tasks Operating the automatic gearbox, e.g. transmitting drive positions, controlling the mechani-

cal selector lever locks, transmitting selector lever tiptronic commands and resetting the
selector lever in the automatic gate.

Diagnostic address 81

Data bus communication Infotainment CAN bus user

Special features • J587 can only be replacded together with the selector mechanism.

• The selector mechanism is not mechanically connected to the automatic gearbox.

Selector lever sensors control unit
J587

Reference

For further information about the selector mechanism, refer to Self Study Programme644 "AudiA4 (type8W)".

Rear final drive 0D3–sport dierential

Designation All-wheel drive control unit J492

Equipment Optional equipment (PR no.: GH2)

Installation location In luggage compartment

Task Controls the torque of the sport dierential's multi-plate clutch

Diagnostic address 22

Data bus communication FlexRay subscriber

Special features • Special procedures must be followed when replacing the control unit.

• The driving dynamics control system is integrated in the suspension control unit J775, and
no longer in the all-wheel drive control unit J492. All that control unit J492 does is execute
the commands issued by J775.

646_025

All-wheel drive control unit
J492

646_026

28

Steering column electronics

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Designation Steering column electronics control unit J527

Equipment Always fitted

Installation location On steering column

Task Connects the steering column stalk and the electrical components in the steering wheel to the

vehicle's electronics.

Diagnostic address 16

Data bus communication FlexRay subscriber

Special feature In conjunction with the multifunction steering wheel, it transfers the LIN signals from the

data bus diagnostic interface J533 (master) to the multifunction steering wheel control unit
J453 (slave).

Steering column electronics control unit
J527

Airbag

Designation Airbag control unit J234

Equipment Always fitted

Installation location Under centre console, front, on centre tunnel

Tasks • Deployment of airbags, seat belt pretensioners and battery isolation igniter

Diagnostic address 15

Data bus communication • FlexRay subscriber

Special feature Inertial sensors for ESC

• Audi pre sense

• Deployment of the pedestrian protection system

• Is connected to the front left (J854) and front right (J855) seat belt pretensioner control

units via a sub-bus system.

• LIN master for seat occupancy recognition control unit J706 (for North American market

only)

646_027

Airbag control unit
J234

646_028

29

Engine control unit

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Designation Engine control unit J623

Equipment Always fitted

Installation location In engine bay, L/H side, in front of plenum chamber

Tasks • Controlling the engine characteristic

• Activation of starter relays J906 and J907

• Function master for start-stop system

Diagnostic address 01

Data bus communication • FlexRay subscriber

• J623 is connected to NO
system.

• LIN master for radiator lourvre control motors 1 and 2 V544 and V550

Special features • Immobiliser user

• Control unit with new plug-in connections. Has a total of 315 pins. New test adapter

VAS6606/23 for test box VAS6606

senders and the particulate sensor (diesel engine) via a sub-bus

x

Start-stop system

As with all Audi models with start-stop system, the engine control
unit J623 is the coordinator for the start-stop function in the
AudiA4.
The AudiA4(type8W) is equipped with a start-stop system in
Version2.0, which was first used in the AudiQ7(type4M).

Engine control unit
J623

646_030

For a history of the start-stop system and a detailed description of
Version2.0, refer to SSP634 "AudiQ7(type4M) Onboard Power
Supply and Networking".

Operating unit 1 for drive and comfort/convenience functions E791

646_080

Start-stop mode button
E693

30

SCR system

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Designation Reducing agent metering system control unit J880

Equipment Always installed in diesel models

Installation location On the underside of the SCR tank

Task Controlling the injection of reduction agent for reduction of the nitrous oxides in the exhaust

gases

Diagnostic address AC

Data bus communication Extended CAN subscriber

Special feature The control unit is identical in all diesel models. The size of the reduction agent tank can vary:

standard SCR tank capaciity 12l; "extended range" SCR tank capacity 24l

Reducing agent metering system control unit
J880

1)

.

646_031

Front A/C control panel

Designation Front air conditioner/Climatronic operating and display unit E87

Equipment Always fitted

• Automatic air conditioning (PR no.: 9AK)

• Automatic air conditioning (PR no.: 9AQ)

Installation location In centre of dash panel

Tasks Controlling:

• Temperature

• Fan speed

• Air flow distribution

Diagnostic address 08

Data bus communication • Hybrid CAN user

• E87 is the LIN master for

• LIN 1: Control motors for flap activation 1–15

• LIN 2: Rear air conditioner/Climatronic operating and display unit E265, fresh air blower

control unit J126, humidity sensor in fresh air intake duct G657, air quality sensor
G238, high pressure sensor G65

Special feature Although the seat seating and seat ventilation switches are integrated in and read in by oper-

ating unit E87, the electrical system control unit J519 is responsible for their activation.

Front air conditioner/Climatronic operating
and display unit
E87
(figure shows deluxe automatic air condi­tioning system)

1)

Optional equipment

646_029

31

Head-up display

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Designation Control unit for windscreen projection (head-up display) J898

Equipment Optional equipment (PR no.: KS1)

Installation location In dash panel, directly in front of instrument cluster

Task Controlling all optical, mechanical and electrical components of the head-up display

Diagnostic address 82

Data bus communication Infotainment CAN bus user

Special features • The control units can only be replaced complete with the other components of the head-up

display.

• To replace the head-up display, the windscreen must be removed.

• When replacing the windscreen, please note: the head-up display requires a special screen

(with wedge-shaped foil).

646_032

Control unit for windscreen projection (head-up display)
J898

32

Rear-view camera

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Designation Rear view camera system control unit J772

Equipment Optional equipment (PR no.: KA2)

Installation location In handle (soft touch) on rear hatch

Task Processing and transfer of images from the area behind the vehicle to the information elec-

tronics control unit 1 J794

Diagnostic address 6C

Data bus communication Extended CAN subscriber

Special feature Control unit, camera and wiring harness form a unit (as shown)

Rear-view camera system control unit
J772
(with built-in camera)

Surround cameras

Designation Surround camera control unit J928

Equipment Optional equipment, available in combination with:

Installation location In luggage compartment, L/H side, behind luggage compartment side trim

Task The control unit reads in the data from the 4 surround-view cameras and generates images

Diagnostic address 6C

Data bus communication • Extended CAN subscriber

• Parking aid plus (PR no.: 7X2)

• Park assist (PR no.: 7X5)

mapping the area around the vehicle.

• Image transfer to instrument cluster by LVDS

646_033

Surround camera control unit
J928

646_034

33

Auxiliary heating

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Designation Auxiliary heater control unit J364

Equipment Optional equipment (PR no.: 9M9)

Installation location In front wheel arch, R/H side, on side member

Tasks • Reading (senders/sensors/switches)

• Temperature sensor, flame monitor

• Switch-on signals of auxiliary heating radio receiver

• Activation (actuators/control elements)

• Fuel metering pump, combustion air blower

• Heater glow plug, heating element for fuel preheating

• Coolant circulation pump, heater coolant shut-o valve

Diagnostic address 18

Data bus communication • Extended CAN subscriber

• LIN master for auxiliary heating radio receiverR64

Special feature Control unit integrated in heater

Auxiliary heating control unit
J364

646_035

34

Audi side assist

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Designation Audi side assist control unit J769 (master)

Audi lane assist control unit 2 J770 (slave)

Equipment Optional equipment (PR no.: 7Y1)

Installation location In rear bumper cover, left and right

Tasks Radar monitoring system for the detection of vehicles (cycles and automobiles) in the area to

the rear and side of the vehicle for

• Audi pre sense rear including Audi side assist

• Rear cross trac assist

• Exit warning

Diagnostic address • 3C–J769 (master)

• CF–J770 (slave)

Data bus communication • Extended CAN subscriber

• Both control units are also interconnected by a sub-bus system.

Special feature The control unit is integrated in the bumper cover. The system has to be calibrated after

removal and installation.

Audi side assist control unit
J769

Audi side assist control unit 2
J770

646_036

35

Electronic Stability Control (ESC)

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Designation ABS control unit J104

Equipment Always fitted

Installation location In engine bay, L/H side

Tasks Controlling:

• Anti lock braking system (ABS)

• Electronic Stability Control (ESC)

• Traction Control System (TCS)

• Electronic Dierential Lock (EDL)

• Torque vectoring

• Multicollision brake

• Electro-mechanical parking brake (EPB)

Diagnostic address 03

Data bus communication FlexRay subscriber

Special features • The control unit camn be replaced separately from the valve block. ESD protective mat

VAS6613 must be used.

• The electro-mechanical parking brake is integrated in the ABS control unit.
Address word53 is no longer used for electro-mechanical parking brake.

646_037

ABS control unit
J104

36

Information electronics

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Designation Information electronics control unit 1 J794

Equipment Always fitted

Installation location In glove compartment

Task Controlling the infotainment systems

Diagnostic address 5F

Data bus communication • Infotainment CAN bus user

• MOST subscriber

• J794 is connected to the MMI display J685 and the multimedia system operating unit E380

via the Modular Infotainment System (MIB) CAN.

Special features • J794 is the system manager and the ring break diagnostics master for the MOST bus.

• J794 is connected to the dash panel insert control unit J285 and the MMI display J685 via

LVDS bus (image transfer for navigation display in instrument cluster or MMI display).

Information electronics control unit 1
J794

Information electronics control unit 1
J794
(back)

TV tuner

Designation TV tuner R78

Equipment Optional equipment (PR no.: QV1)

Installation location In luggage compartment, R/H side, behind luggage compartment side trim

Task TV reception

Diagnostic address 57

Data bus communication MOST subscriber

646_038

TV tuner
R78

646_039

37

Sound amplifier

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Designation Digital sound package control unit J525

Equipment Optional equipment (PR no.: 9VS)

Installation location In luggage compartment, L/H side, behind luggage compartment side trim

Task Activation of up to 19 speakers

Diagnostic address 47

Data bus communication MOST subscriber

Digital sound package control unit
J525

646_040

38

Rear Seat Entertainment (Auditablet)

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Ξ Contents

Designation Control unit for rear left information display and operating unit J648

Equipment Optional equipment (PR no.: 9WE or 9WF)

Installation location In the driver seat backrest

Task Interface between the Auditablet for Rear Seat Entertainment, rear left and the vehicle elec-

tronics

Diagnostic address 5E

Data bus communication Modular Infotainment System CAN subscriber

Bracket for multimedia system display unit 3
R315

Designation Control unit for rear right information display and operating unit J649

Equipment Optional equipment (PR no.: 9WE or 9WF)

Installation location In the front passenger seat backrest

Task Interface between the Auditablet for Rear Seat Entertainment, rear right and the vehicle elec-

tronics

Diagnostic address 4E

Data bus communication Modular Infotainment System CAN subscriber

Control unit for rear left information display
and operating unit
J648

646_041

39

Suspension control unit

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Ξ Contents

Designation Suspension control unit J775

Equipment Optional equipment

Installation location Under centre console, front, on centre tunnel

Tasks Wheel damping control

• Reading (senders/sensors/switches)

• Level control system sensor (4pcs.)

• Activation (actuators/control elements)

• Damper adjustment valve (4 pce.)

Diagnostic address 74

Data bus communication FlexRay subscriber

Special feature The suspension control unit J775 is responsible for driving dynamics control. In models with a

sport dierential, J775 sends the commands to the all-wheel drive control unit J492, where
these commands are put into action.

Suspension control unit
J775

646_042

Power steering

Designation Power steering control unit J500

Equipment Always fitted

Installation location Connected to the steering gear.

Tasks Controlling:

• power steering

• Servotronic speed-responsive power steering

• Corrective steering inputs in conjunction with Audi active lane assist, park assist, evasion

assist and trailer assist

• Corrective steering inputs in conjunction with ESC

Diagnostic address 44

Data bus communication FlexRay subscriber

Special feature The control unit with power steering motor can only be replaced together with the steering gear.

Power steering control unit
J500

646_043

40

Dynamic steering

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Ξ Contents

Designation Active steering control unit J792

Equipment Optional equipment (PR no.: 1N8)

Installation location In driver's side footwell, under the floor covering

Tasks • Calculating the superimposition angle required to implement the variable steering ratio.

• Correcting the calculated superimposition angle of the stabilising function through ESC

intervention.

• Reading (senders/sensors/switches)

• Index sensor

• Motor position sensor

• Activation (actuators/control elements)

• Dynamic steering actuator

• Dynamic steering lock

Diagnostic address 1B

Data bus communication FlexRay subscriber

Special features Basic setting is necessary after:

• replacement by a new or dierent active steering control unit J792

• replacement by a new or dierent steering column

• replacement by a new or dierent steering angle sensor G85 or recalibration

• Changing the wheel alignment values

• Disconnecting the actuator from the steering column or the actuator from the steering

gear

646_044

Active steering control unit
J792

41

Exterior lighting

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Ξ Contents

Headlight variants

In the case of the Audi A4, a distinction is made between the
following headlight versions:

• Xenon headlight (ECE1) and SAE2))

• LED headlight (ECE1) and SAE2))

• Audi Matrix LED headlight (ECE1))

To remove headlights, the bumper cover must be taken o before­hand. The headlights are connected to the vehicle body by means
of adjusting elements. Thus, it is possible to align the headlights
exactly with the other body parts. Before the headlight can be
removed from the vehicle, the headlight washer nozzle must be
unclipped from the headlight.

Xenon headlight

The figure shows the left headlight in the ECE1) version.

Sealing cover in headlight housing –access for changing bulb in foglight
"Service"

Headlight range control servomotor

V48

In the event of damage to the upper and inner headlight attach­ments, repair tabs can be attached to the headlight housing. The
parts marked "Service" in the exploded-view diagrams of the
headlights on the following pages can be replaced individually in
the event of damage.
For information as well as the corresponding spare part numbers,
please refer to the workshop manual or the electronic parts cata­logue.

Reflectors for LED daytime running light and side light

Turn signal bulb, front left
M5
"Service"

1)

ECE = for European market

2)

SAE = for North American Region

Note

"Fog light bulb L22" (for the all-weather light function) can be accessed via a cover on the back of the headlight housing and
can be replaced after the headlight has been installed.

Fog light bulb, left
L22
"Service"

Left gas discharge lamp
L13
"Service"

646_054

42

LED headlights

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Ξ Contents

The figure shows the left headlight in the ECE1) version.

Headlight range control servomotor
V48

Power module 1 for left LED headlight
A31
"Service"

Headlight module

Audi Matrix LED headlight

The figure shows the left headlight.

Headlight range control servomotor
V48

Power module 1 for left LED headlight

A31
"Service"

Control unit for light control, left
J1018
"Service"

Dipped beam module

Fibre optic cable for daytime running light /
side light, turn signal

646_055

Left headlight fan
V407

Matrix headlight module

1)

ECE = for European market

2)

SAE = for North American Region

Reference

For information on parts replaceable by service centres and the corresponding spare part numbers, please refer to the
workshop manual or the electronic parts catalogue.

Control unit for light control, left
J1018
"Service"

Dipped beam module

Fibre optic cable for daytime running light /
side light, turn signal

646_056

43

Xenon headlight

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Ξ Contents

The figure shows the L/H headlight in the ECE1) version.

Daytime running light/
parking light

Dipped beam/
main beam

646_057

Turn signal All weather light

Light functions Type of bulb used Power

Daytime running light 4 LEDs 5watts

Side light Parking light is dimmed if light function is active

Dipped beam Gas discharge lamp D5S 25watts

Motorway light (only ECE

1)

) Raises dipped beam by means of headlight range adjustment

Main beam Changes over dipped beam using shutter

All weather light Bulb H8 35watts

Turn signal Bulb PSY24W 24watts

2)

Sidemarker (SAE only

) 1 LED 0.5watts

Special features of the light functions

The daytime running lights in the ECE1) version are dimmed for the
duration of the turn signaling cycle (in the SAE2) version they are
switched o). The all-weather light in both versions is deactivated
during the turn signalling cycle as soon as the vehicle exceeds a
speed of 40 kph.

The left and right dipped beam shutter motors V294 and V295 are
used for switching between dipped beam and main beam. The
LEDs for the side light function and the dipped beam function of
the gas discharge lamp are used for the Coming Home / Leaving
Home function.

1)

ECE = for European market

2)

SAE = for North American Region

44

Schematic diagram of the activation mechanism

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Ξ Contents

Electrical system control unit
J519

• Voltage supply

• Activation of light functions

• Calculation/activation of headlight range adjust-

ment

Convenience CAN

Gas discharge headlight
(L/H side of vehicle)

• Control unit

• Dipped beam shutter

• Fog light bulb, left

• Turn signal bulb, front left

Discrete lines

• LEDs for parking lights and daytime running lights

• LEDs for front left side marker light (SAE

• Beam-height adjustment servo motor

2)

)

646_058

Activation

If the vehicle is equipped with xenon headlights, the electrical
system control unit J519 is responsible for power supply as well as
for activating all bulbs in the headlight. J519 also activates the

dipped beam shutter and the headlight range adjustment control
motor.

Headlight range adjustment

The gas discharge headlight has automatic static headlight range
adjustment. This means that changes in headlight range are
compensated by loading of the vehicle. However, changes caused
by rolling movements of the vehicle under acceleration and braking
are not compensated.
The electrical system control unit receives information on ride
height from either the central control unit for comfort/conven­ience system J393 or, if installed, the suspension control unit J775.

Service

The basic setting of the headlight range adjustment function is
configured in the electrical system control unit J519. The foglamp
bulb can be replaced with the headlights fitted. This bulb can be
accessed via a cover on the back of the headlight housing. The
headlight must be removed in order to replace the gas discharge
lamp or the turn signal lamp.

Adaptation for driving on the opposite side of the road

It is not necessary to adapt the headlights. No further action is
needed in order to meet the statutory requirements.

Optional equipment

The xenon headlight can be combined with main beam assist
(PRno.: 8G1) as well as a headlight washer system (PR no.: 8X1).

1)

ECE = for European market

2)

SAE = for North American Region

45

LED headlight

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Ξ Contents

The figure shows the L/H headlight in the ECE1) version.

Daytime light/
side light/
turn signal

Main beam Dipped beam/

motorway light

646_059

Daytime running light/
parking light

Turning light/
all-weather light/
static cornering light/
intersection light/
town light

Light functions Type of bulb used Power

Daytime running light 7LEDs with plastic optical fibres 18watts

Side light Parking light is dimmed if light function is active

Dipped beam 11 LEDs 20watts

Motorway light Raises dipped beam by means of headlight range adjustment

Main beam 6 LEDs 20watts

All weather light 3 LEDs 10watts

Turning light 0–40kph, turn signal responsive

Static cornering light 0–70kph, steering angle responsive

Intersection light (only ECE

Town light (only ECE

1)

) Turning light on both sides and dipped beam

1)

) Dimmed turning light on both sides and dimmed dipped beam

Turn signal 8 LEDs 18watts

2)

Sidemarker (SAE only

) 1 LED 0.5watts

Daytime running light/
parking light

Special features of the light functions

The "upper" daytime running light is dimmed for the duration of
the turn signalling cycle. The "lower" daytime running light is
dimmed to side light level. This applies to both the ECE1) version
and the SAE2) version. The all-weather light, the intersection light
and the town light are not aected by turn signal operation.

1)

ECE = for European market

2)

SAE = for North American Region

46

The LEDs for the side light function and the dipped beam function
are used for the Coming Home / Leaving Home function.

Schematic diagram of the activation mechanism

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Ξ Contents

External terminal 15 supply

LED headlights
(L/H side of vehicle)

Electrical system control unit
J519

Voltage supply

Convenience CAN

Discrete lines

Voltage supply

• Activation of light func­tions

• Calculation/activation of
headlight range adjust­ment

Discrete line

Sub-bus system

Power module 1 for left LED headlight A31

• LEDs for left dipped beam headlight

• LEDs for left dipped beam headlight

• LEDs for left static cornering light

Control unit for light control, left J1018

• LED for left side marker light (SAE

• Left headlight range control motor

Left LED module for daytime running lights and parking
lights L176

• LEDs for parking lights and daytime running lights

• LEDs for left turn signal

2)

)

Discrete lines

646_060

Activation

If the car has LED headlights, the electrical system control unit
J519 supplies voltage to power modules 1 for left/right LED
headlight A31/A27 and the left/right control units for light control

J1018/J1023. J519 also communicates with these control units via
a sub-bus system.

Power modules 1 for left/right LED headlight A31/A27 are respon­sible for activating the LEDs for dipped beam, main beam and
static cornering light (turning light). The control units have self
diagnostic capability and can be accessed using address
codesD6/D7.

The left/right control units for light control J1018/J1023 are
responsible for the parking light/daytime running light, turn
signals, side marker light (SAE2)) and the headlight range adjust­ment servomotor. The control units have self diagnostic capability
and can be accessed using address codes 29/39.

Headlight range adjustment

The LED headlight has automatic dynamic headlight range adjust­ment. Changes in the range of the headlight beam due to loading
of the vehicle as well as braking and accelerating are compensated.
The electrical system control unit receives information on ride
height from either the central control unit for comfort/conven­ience system J393 or, if installed, the suspension control unit J775.

Service

The basic setting of the headlight range adjustment function is
configured in the electrical system control unit J519. LED head­light bulbs cannot be replaced. Only the outer control units can be
replaced individually after removing the headlights.

Adaptation for driving on the opposite side of the road

It is not necessary to adapt the headlights. No further action is
needed in order to meet the statutory requirements.

Optional equipment

The LED headlight can be combined with main beam assist
(PRno.:8G1) as well as a headlight washer system (PR no.: 8X1).

1)

ECE = for European market

2)

SAE = for North American Region

47

Audi Matrix LED headlight

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Ξ Contents

Daytime light/
side light/
turn signal

Main beam/
Matrix Beam headlight

Dipped beam/
motorway light

646_061

Daytime running light/
parking light

Turning light/
all weather light/
intersection light/
town light

Light functions Type of bulb used Power

Daytime running light 7LEDs with plastic optical fibres 18watts

Side light Parking light is dimmed if light function is active

Dipped beam 11 LEDs 20watts

Motorway light Raises dipped beam by means of headlight range adjustment

Matrix Beam headlight 12 LEDs 29watts

Turning light 3 LEDs 10watts

All weather light Dimmed turning light on both sides and dimmed dipped beam

Intersection lights Turning light on both sides and dipped beam

Town light Dimmed turning light on both sides and dimmed dipped beam

Turn signal (dynamic) 9 LEDs 18watts

Daytime running light/
parking light

Special features of the light functions

The "upper" daytime running light is dimmed for the duration of
the turn signalling cycle. The "lower" daytime running light is
dimmed to side light level. The Audi MatrixLED headlight supports
the dynamic turn signal function. The all-weather light, the inter­section light and the town light are not aected by turn signal
operation.

48

The LEDs for the side light function and the dipped beam function
are used for the Coming Home / Leaving Home function.
The Audi MatrixLED headlight is not available in the North Ameri­can Region.

Schematic diagram of the activation mechanism

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Ξ Contents

Audi Matrix LED headlights
(L/H side of vehicle)

Convenience CAN

FlexRay

Electrical system control unit
J519

• Voltage supply

• Activation of light functions

• Calculation/activation of headlight range adjustment

Front camera for driver assistance systems
R242

• Monitoring trac

• Oncoming trac and vehicles ahead

• Calculation/activation of the Matrix Beam headlight

External terminal 15 supply

Control unit for light control, left J1018

Discrete line

• Left headlight range control motor

Left power module for headlight auxiliary functions
A47

Discrete line

• Dynamic turn signal function

• Daytime running light / parking light

Power module 1 for left LED headlight A31

• LEDs for left dipped beam headlight

Sub-bus system

• LEDs for left dipped beam headlight

• LEDs for left cornering light

• Left headlight fan

Left power module for Matrix headlight A44

LIN

LIN

Activation

If the car has Audi Matrix headlights, the electrical system control
unit J519 supplies voltage to power modules 1 for left/right LED
headlight A31/A27 and the left/right control units for light control

J1018/J1023. J519 also communicates with these control units via
a sub-bus system.

Power modules 1 for left/right LED headlight A31/A27 are respon­sible for activating the LEDs for dipped beam, main beam and
static cornering light (turning light) and the headlight fan. In
addition, they are connected to the LED modules for the Matrix
Beam headlight via a LIN line. The control units have self diagnos­tic capability and can be accessed using address codes D6/D7.

The left/right control units for light control J1018/J1023 are
responsible for the parking light/daytime running light and the
headlight range adjustment servomotor. The control units have
self diagnostic capability and can be accessed using address
codes29/39. The LED module for the dynamic turn signal function
is activated via a LIN line.
The decision whether dynamic or conventional flashing is required
is sent from the electrical system control unit J519 to the left/right
control units for light control J1018/J1023 via the sub-bus line.

646_062

Headlight range adjustment

The Audi Matrix LED headlight supports automatic dynamic head­light range adjustment. Changes in the range of the headlight
beam due to loading of the vehicle as well as braking and acceler­ating are compensated.
The electrical system control unit receives information on ride
height from either the central control unit for comfort/conven­ience system J393 or, if installed, the suspension control unit J775.

Service

The basic setting of the headlight range adjustment function is
configured in the electrical system control unit J519. Matrix LED
headlight bulbs cannot be replaced. Only the outer control units
can be replaced individually.

Adaptation for driving on the opposite side of the road

It is not necessary to adapt the headlights. No further action is
needed in order to meet the statutory requirements.

1)

ECE = for European market

2)

SAE = for North American Region

49

Dynamic turn signal function

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Ξ Contents

The dynamic turn signal function is implemented in the
AudiA4(type8W) both for the lighting of the ECE1) version and
the SAE2) version.

The LEDs illuminate in a sweeping motion from the inside out­wards. The flashing LEDs all switch o simultaneously.

Activation

The electrical system control unit J519 instructs the headlights
and the central control unit for comfort/convenience system J393
to activate the turn signal function. J393 thereupon activates the
LEDs for the turn signal function in the tail lights. An electronic
module in the headlights or in the tail lights is responsible for
sequential activation of the LEDs.
Since sequential flashing is not desirable with all turn signal
functions, the electrical system control unit J519 informs the
headlights via a sub-bus system whether conventional or sequen­tial flashing is required. The tail lights are supplied with the infor­mation from the central control unit for comfort/convenience
system J393 via a discrete line.

646_074

Conventional flashing is used, for example, to indicate a crash/
collision or an emergency or as a hazard warning after heavy
braking.
The dynamic turn signal function, on the other hand, is used when
indicating direction and when the hazard warning lights are manu­ally activated, as well as for central locking acknowledgement and
after confirmation of successful programming.

Equipment

The dynamic turn signal function is implemented in the front end
of an AudiA4 with AudiMatrixLED headlights as well as in con­junction with all LED tail light versions.

1)

ECE = for European market

2)

SAE = for North American Region

50

Tail lights

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In the AudiA4(type 8W) the rear light functions are distributed to
the tail lights in the body side panels and the tail lights in the rear
hatch. This statement applies equally to the AudiA4 saloon and
the AudiA4Avant. However, the various light functions are distrib­uted dierently in the saloon and in the Avant (refer to tables).

Basic tail light (PR no.: 8SA)

The figure shows the L/H basic tail light of the Audi A4 saloon.

Brake light 1/
Tail light 1

Brake light 2/
Tail light 2

A distinction is made between the following versions of the tail
lights:

• ECE basic tail light

1)

• LED tail lights (ECE1) and SAE2))
The tail lights are activated irrespective of variant by the central
control unit for comfort/convenience system J393.

Tail light 3

Reversing light Rear fog lightTurn signal

Light functions Saloon Avant

Brake light 1 P21W

Tail light 1 25 % activation

Brake light 2 P21W

Tail light 2 32 % activation

Turn signal PY21W

Reversing light W16W

Tail light 3 W16W

Rear fog light

Special features of the light functions

The tail lights are also activated if the vehicle is equipped with a
Coming Home / Leaving Home function. The basic tail light does
not support the dynamic turn signal function. In the case of the
tail lights on the saloon model, the rear fog light is deactivated

5)

Bulb/lamp Power Bulb/lamp Power

H21W

3)

3)

3)

3)

3)

3)

4)

– 28% activation approx. 4.5watts W16W4) – 42 % activation approx. 7watts

4)

21watts W16W

approx. 5watts 28 % activation

21watts W16W

approx. 7watts 28 % activation

21watts PY21W

16watts W16W

21watts H21W

Service

To replace the bulbs/lamps in the tail lights, the light in question
must be removed. This applies to both the tail lights in the body
side panels and the tail lights in the rear hatch. All bulbs can be
replaced.

when the rear hatch is open. In the case of the tail lights on the
Avant model, the reversing light is also deactivated.

646_071

3)

3)

3)

3)

3)

4)

4)

16watts

approx. 4.5watts

16watts

approx. 4.5watts

21watts

16watts

21watts

1)

ECE = for European market

2)

SAE = for North American Region

3)

Tail lights in the body side panels

4)

Tail lights in the rear hatch

5)

One side only (L/H side only in RHD models, R/H side only in LHD models)

51

LED tail light (PR no.: 8SP)

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Ξ Contents

The figure shows the L/H LED tail light of the saloon model in the ECE1) version.

Turn signal Turn signal Tail light

646_072

Brake light Reversing light Rear fog lightTail light Tail light

Light functions Saloon

1)

Bulb/lamp Power Bulb/lamp Power

Turn signal (dynamic)

Tail light

Brake light

3)

3)

Turn signal (dynamic)

Reversing light

Tail light

4)

Rear fog light

3)

4)

4)

4), 5)

12 LEDs 10watts 12 LEDs 11watts

33 LEDs 10watts 30 LEDs 8watts

6 LEDs 6watts 9 LEDs 8watts

18 LEDs 20watts 15 LEDs 14watts

4 LEDs 6watts 2 LEDs 7watts

15 LEDs 4watts 18 LEDs 4watts

2 LEDs 4watts 2 LEDs 4watts

Special features of the light functions

The tail lights are also activated if the vehicle is equipped with a
Coming Home / Leaving Home function. Light functions are not
deactivated when the rear hatch is open.
The LED tail light supports the dynamic turn signal function.

1)

Avant

Service

No bulbs/lamps can be replaced in the LED tail light. In the event
of a fault, the complete lamp must be replaced.

1)

ECE = for European market

2)

SAE = for North American Region

3)

Tail lights in the body side panels

52

4)

Tail lights in the rear hatch

5)

One side only (L/H side only in LHD models, R/H side only in RHD models)

LED tail light (PR no.: 8SK)

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Ξ Contents

The figure shows the L/H LED tail light of the saloon model in the SAE2) version.

sidemarker

Brake light/
turn signal

Tail light Brake light

Brake light/
turn signal

Reversing light Rear fog lightTail light/

Tail light

646_073

Light functions Saloon

2)

Bulb/lamp Power Bulb/lamp Power

Brake light/turn signal
(dynamic)

Tail light

Brake light

Turn signal (dynamic)

Reversing light

Tail light

Rear fog light

3)

3)

3)

4)

4)

4)

4), 5)

12 LEDs 10watts 12 LEDs 14watts

33 LEDs 10watts 30 LEDs 8watts

6 LEDs 6watts 9 LEDs 14watts

18 LEDs 8watts 15 LEDs 9watts

4 LEDs 6watts 2 LEDs 7watts

15 LEDs 4watts 18 LEDs 5watts

2 LEDs 4watts 2 LEDs 4watts

Special features of the light functions

The tail lights are also activated if the vehicle is equipped with a
Coming Home / Leaving Home function. Light functions are not
deactivated when the rear hatch is open. If the tail light is acti­vated and the brake light is simultaneously active, the LEDs for the
brake light/turn signal in the rear hatch lamp are deactivated. If
the tail light is activated and the turn signal is simultaneously
active, the LEDs for the brake light/turn signal in the rear hatch
lamp are also active. Amber-coloured LEDs are used for the turn
signal in the SAE

2)

version, while yellow LEDs are used in the ECE1)

version.

2)

Avant

In the case of the AudiA4, the dynamic turn signal function is also
supported in the SAE2) version. In this version, the LEDs for the
turn signal/brake light are briefly activated in a dimmed manner
when the turn signals are activated. After that, the LEDs for the
turn signal function are dynamically activated in an alternate
fashion to produce the dynamic eect.

Service

No bulbs/lamps can be replaced in the LED tail light. In the event
of a fault, the complete lamp must be replaced.

1)

ECE = for European market

2)

SAE = for North American Region

3)

Tail lights in the body side panels

4)

Tail lights in the rear hatch

5)

One side only (L/H side only in LHD models, R/H side only in RHD models)

53

High-level brake lights / number plate lights

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Ξ Contents

Activation

As with the number plate light, the high-level brake light is acti­vated by the central control unit for comfort/convenience system
J393.

High-level brake lights

AudiA4saloon

The high-level brake light of the saloon model is located inside the
vehicle behind the rear window. 18LEDs with a power output of
4watts support the brake light function.
In the event of a fault, the complete high-level brake light must be
replaced.

The high-level brake light and the number plate lights stay acti­vated even the when luggage compartment flap is open.

If the AudiA4saloon has so-called "privacy" glazing, 18LEDs with
a power output of 11watts are used to compensate for the light
absorbed by the tinted glass.

646_075

High level brake light bulb
M25

54

AudiA4Avant

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In the Avant model, the high-level brake light is integrated in the
rear spoiler. The 18LEDs have a power output of 4watts.

In the event of a fault, the complete high-level brake light must be
replaced.

Number plate lights

The number plate lights on the Audi A4 use LED technology irre­spective of tail light version. Each of the 2 number plate lights is
clipped into the luggage compartment flap panel and has 2 LEDs.

646_076

High level brake light bulb
M25

646_077

55

Audi drive select

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Functional characteristics

The AudiA4 is equipped with Audi drive select.
With Audidrive select, it is possible to modify the vehicle charac­teristic. The mode can be changed when the car is stationary or
while driving. Condition: "Terminal 15 on".

In the Audi A4 (type 8W), the driver can select between the follow­ing drive modes:

• eciency

• comfort

• auto

• dynamic

• individual

Displays and operation

The Audidriveselectsystem can be configured either using the
Audidriveselect button in operating unit 1 for drive and comfort/
convenience functions E791 in the centre console or using the
multimedia systemoperating unit E380.

In any case, the power steering and the engine characteristic are
aected.
Audi drive select also aects the following equipment:

• Automatic gearbox

• Sport dierential

• Air conditioning system

• Cornering light

• Ambient lighting

• Dynamic steering

• Damper control

• Cruise control system

• unit 2

• Audipresensebasic / presensecity

• Start-stop system

Depending on the equipment specification, the drive mode can
also be selected on the multifunction steering wheel. In the
AudiA4, the options menu is displayed on the MMI screen or in the
instrument cluster.

Operating unit 1 for drive and comfort/convenience functions
E791

646_078

Multimedia system control panel
E380

646_079

56

Audi drive select function

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The following systems are, among others, influenced by drive
select:

System Vehicle characteristic

Engine and auto­matic gearbox

Steering The steering can be adapted with the regard to steering assistance. A distinction is made here between

Dynamic steering The following applies to models with dynamic steering:

Damper control Audidriveselect allows the damper control system to be configured for sporty (dynamic), comfort-oriented

Cornering light The cornering light adapts the main beam to the curvature of the corner in a speed-responsive manner. The

Air conditioning
system

Depending on mode, the engine and automatic gearbox react to accelerator inputs in a more spontaneous or
more balanced way. In the sporty dynamic mode, the gear shift points are adjusted to higher up the rev
band. When the vehicle is running in eciency mode, on the other hand, the shift points (automatic gearbox)
are adjusted to lower down the rev band in order to save fuel.

3characteristics ranging from comfortable (comfort) and balanced (auto) to sporty (dynamic).

To minimise steering eort for the driver, the steering ratio is adjusted to the speed at which the vehicle is
travelling. At higher speeds, the steering is configured for less sensitivity in order to improve handling. At
lower speeds, the steering is more direct in order to minimise steering eort for the driver during manoeu­vring, for example. In addition, the dynamic steering system provides a more agile steering response at low
and medium speeds.

(comfort) or balanced (auto) response.

swivelling action of the lights and beam strength are also adapted to the mode.

The air conditioning system is only aected in eciency mode, when it operates in a highly fuel-ecient
way.

Cruise control
system

Adaptive cruise
control (ACC)

Sport dierential In comfort mode, activation of the sport dierential is kept at a minimum. Primarily, load-change reactions

The cruise control system is only aected in eciency mode, when it operates in a highly fuel-ecient way.

Depending on drive select mode, the acceleration response options range from comfortable (comfort) to
sporty (dynamic). Accordingly, the adaptive cruise control also reacts to the driving style of the driver in front
in a more balanced or more spontaneous way. The eciency mode chooses a set-up for maximum economy.

are eectively damped so that the car has a very balanced response.
In auto mode, the sport dierential is configured for optimal handling dynamics. The car steers very respon­sively through corners.
In dynamic mode, the sport dierential is at its most noticeable. The dynamic handling has distinctly sports
feel.

Functional features

• The vehicle remembers the last selected mode and the indi-
vidual mode configuration when it is restarted.

• To active the newly selected mode for the engine, too, the
accelerator must be briefly released (idle position) or briefly
pushed down into the full throttle position.

• To activate the newly selected mode for the steering as well,
the steering wheel must also be moved into the straight-ahead
position (zero position).

• The following applies to models with an automatic gearbox: In

dynamic mode, gearbox positionS is automatically selected. In
eciency mode, gearbox positionE is automatically selected.

• The eciency mode is unavailable when towing a trailer.

• The following applies to models with a manual gearbox: if the

accelerator is pressed down fully beyond the point of resistance
at full throttle in eciency mode, engine power output is
automatically adjusted to provide maximum acceleration.

• On some models, maximum speed is only achieved in auto and
dynamic modes.

• The start-stop system is generally activated when the vehicle is
running in eciency mode.

57

Vehicle electronics

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Interior lighting

As with the AudiQ7(type4M), the interior lighting in the
AudiA4(type8W) subdivided into 3production numbers depend­ing on trim level:

• QQ0 basic interior lighting package

• QQ1 lighting package

• QQ2 background lighting

QQ0

Glove compartment lighting, luggage compartment lighting
The glove compartment lighting in the AudiA4(type8W) is the
only lighting which uses conventional bulbs/lamps.

QQ1

Vanity lights, footwell lights, cupholder light, centre console
background lighting, entry light, door panel lighting in the door
trims and door inner handle lighting
White light and LED technology are exclusively used as light
sources.

QQ2

Contour lighting in the door trim, door pocket lighting.
The LEDs are coloured. 30 light colours are available. The door
pocket lighting in the AudiA4(type8W) is non-capacitive. An
exception is the LED in the door inner handle which lights up in
white only.

The list of interior lighting features with the various production
numbers always includes the equipment with lower production
numbers.

The background lighting QQ2 is controlled by a background light­ing module. The background lighting module is a software function
and is integrated in the electrical system control unit J519.

J519 is the RGB master. RGB denotes the colours red, green and
blue. The colour profiles are produced by additive mixing of these
colours. In the case of additive colour mixing, the human eye is
able to discern multiple wavelengths simultaneously and in quick
succession, but the dierent colours cannot be resolved and
appear as a single colour to the eye.

Apron lighting

In the AudiA4(type8W), the apron lighting is provided by 2LEDs
per door. These LEDs also function as door handle lights. In the
new AudiA4Avant, a single light is integrated in the rear hatch as
apron lighting and illuminates the area in front of the luggage
compartment when the rear hatch is open.

646_004

58

Interior door trim lighting

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Background lighting as shown using the door trims as an example
–the door warning light is passive, but may use a conventional
bulb/lamp depending on country.

Front door trim

Door panel lighting

Door warning light (passive)

Inner door handle light Contour lighting

In the case of the exterior lighting, the apron lighting is integrated
in all 4 door handles in conjunction with PR nos. QQ1 and QQ2.
Unlike the AudiQ7(type4M), the door pocket lighting is not
capacitively controlled.

Exit warning
(with optional assistance system)

Door pocket lighting

Rear door trim

Door panel lighting

Door warning light (passive)

646_005

Speaker lightingEntry light

Inner door handle light Contour lighting

Door pocket lighting

646_006

Entry light

59

Function and control unit architecture

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Interior and background lighting

The LEDs of the interior and background lighting are controlled by
various control units which are networked with one another via the
convenience CAN. These are:

• Electrical system control unit J519

• Central control unit for comfort/convenience system J393

• Driver side door control unit J386

• Front pass. side door control unit J387

WX2

Rear left reading
light

WX3

Front left reading
light

Vanity light, left/
right

Glove box

The following control units connected by LIN bus are also used:

• Door control unit, rear driver side J926

• Rear passenger side door control unit J927

• Roof electronics control unit J528

• Front overhead module WX3

• Interior light, rear centre WX2

Rear right reading
light

J528

LIN2

Front right reading
light

Front footwell light

Rear footwell light

Apron lighting

Door warning

1)

light

Entry light

Inner door handle

Speaker

Door warning

1)

light

Entry light

Inner door handle

Apron lighting

J386

2)

LIN

J926

J519

Convenience CAN

J393

J387

2)

LIN

J927

Storage
compartment

Apron lighting

Door warning

1)

light

Entry light

Inner door handle

Speaker

Door warning

1)

light

Entry light

Inner door handle

Apron lighting

1)

Country-dependent, otherwise passive

2)

Door control unit LIN bus

3)

AudiA4Avant only

60

Luggage compartment

Apron lighting
Rear hatch

3)

646_007

RGB components

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The RGB components of the background lighting are controlled by
the electrical system control unit J519. The individual LEDs or
optical fibres are supplied via 2 LIN bus lines.

J519

LIN5

Door shoulder

Speaker

Door pocket

LIN6

Footwell Cupholder

Centre console

Footwell

Door shoulder

Speaker

Door pocket

Door shoulder

Speaker

Door pocket

Footwell Footwell

Door shoulder

Speaker

Door pocket

646_008

61

Overhead module

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The overhead module is used to activate and read in the following
components:

• Roof electronics control unit J528

• Sliding sunroof operating button

• Garage door operating unit E284

• Front interior lights

• Hands-free telephone microphone

• Front passenger airbag OFF warning lamp K145

Sliding sunroof operating button

Microphone

The interior lights are capacitive, i.e. they are controlled by touch.
The interior lights use LED technology.
The roof electronics control unit J528 is a LIN subscriber of the
electrical system control unit J519.

Motion detectors of the interior monitoring system
integrated in the anti-theft alarm

Garage door operating unit
E284

Microphone

646_009

62

Interior light

Interior light

Passenger airbag OFF warning lamp
K145

Anti-theft alarm

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The anti-theft alarm of the AudiA4(type8W) is largely identical to
the systems used in current Audi models.
The windows in the rear compartment of the AudiA4Avant are
also equipped with glass breakage sensors.

The anti-theft alarm sensor G578, which comprises the interior
monitoring sensor G273 and the vehicle inclination sensor G384,
and the alarm hornH12 are LIN bus subscribers of the central
comfort/convenience system control unit J393. G578 and H12 are
connected to J393 via dierent LIN bus lines.

J393

Convenience CAN

LIN1

H12

LIN2

G273

G384

G578 V53

A new feature of the AudiA4 and its derivatives is that the alarm
(if activated) trips if the vehicle control units are accessed via the
diagnostic connector T16 or via the on-board diagnostics (OBD).

F124F123

G304

1)

Key:

F123 Rear hatch contact switch for anti-theft alarm
F124 Key contact switch in lock cylinder, anti-theft alarm system,

central locking system

G183 Glass breakage sensor for rear left side window
G184 Glass breakage sensor for rear right side window
G273 Interior monitoring sensor

G184

G183

Ground

G304 Glass breakage sensor for rear window
G384 Vehicle inclination sensor
G578 Sensor for anti-theft alarm system
H12 Alarm horn
J393 Central control unit for comfort/convenience system
V53 Central locking motor in rear hatch

1)

1)

646_045

1)

AudiA4Avant only

63

Central locking

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The vehicle can be centrally locked and unlocked in various ways:

• Using the remote control key

• Via the sensors in the door handles (advanced key)

• Manually via the locking cylinder in the driver's door

• Using the inner central locking switch (door trim)

Components

Interior aerial 1 for entry and
start authorisation
R138

Front pass. side
door control unit
J387

In the case of the AudiA4, the door handle sensors are used for
locking and unlocking with the advanced key. The door handle
sensors are not deactivated after 72h. This is no longer necessary
due to the very low static current.

Aerial for entry and start
authorisation, right
R201

Door control unit,
rear pass. side
J927

Luggage compartment aerial for
entry and start authorisation
R137

Locking button in
the rear hatch
E806

Entry and start authori­sation control unit
E408

Driver side door
control unit
J386

Door control unit,
rear driver side
J926

Aerial for entry and start
authorisation, left
R200

646_065

Rear hatch power
opening control unit
J938

Central control unit for
comfort/convenience
system
J393

64

System overview

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The system overview shows the theoretical maximum specifica­tion. The ABScontrol unit J104 receives the vehicle speed signal
required for the Autolock function via the central control unit for
comfort/convenience system J393.

Rear hatch
control unit
J605

Central control unit for comfort/convenience system
J393

Interior locking button,
driver side
E308

Driver side
door control unit
J386

Locking button in the
rear hatch
E806

Tank flap remote
release switch
E204

Door control unit,
rear driver side
J926

All personalised settings are visualised on the MMI displayJ685.
The exterior door handle contact sensors in all 4 doors are con­nected directly to the central control unit for comfort/convenience
system J393.

Rear hatch handle
release button
E234

Exterior door handle
contact sensors
G415–G418

Rear hatch opening
sensors 1 and 2,
in rear bumper
G750, G760

Rear hatch power open­ing control unit
J938

Exterior door handle
touch sensor, driver side
G415

Interior locking button,
front pass. side
E309

Front pass. side
door control unit
J387

Exterior door handle
touch sensor,
front passenger side
G416

Data bus diagnostic interface
J533

Exterior door handle
central locking button,
rear left door
E371

Door control unit,
rear pass. side
J927

Exterior door handle
central locking button,
rear right door
E372

Information electronics
control unit 1
J794

MMI display
J685

Multimedia system
operating unit
E380

ABS control unit
J104

Key:

Convenience CAN

Infotainment CAN

Modular Infotainment Platform (MIB) CAN

646_066

FlexRay

LIN bus

Discrete cable

65

Sensor-controlled luggage compartment release

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The "sensor-controlled luggage compartment release" option is
only available in combination with the "advanced key" option. A
further requirement for opening and closing the rear hatch is that
the car key is within the detection range of the luggage compart­ment aerial for entry and start authorisation R137.

The rear hatch of the Audi A4 can only be opened with a foot
gesture.

Starting scenario

Stand about 20 cm behind the rear end of the vehicle and then
perform a simple swipe of the foot and shin as closely as possible
to the bumper. The shin must be within the upper range of the
sensor and the foot within the lower range of the sensor. Quickly
retract the foot and shin so that both are outside the range of the
sensor.
Closing of the rear hatch is annunciated by a warning signal and
can be interrupted by repeating the movement described above.

The rear hatch of the AudiA4Avant can be opened or closed with a
foot gesture.
The vehicle is not locked when the rear hatch is closed with a foot
gesture.

There are also twin buttons in the luggage compartment: one
button for closing the rear hatch only and one button for locking
the vehicle. In addition, the driver can close the rear hatch using
either the button in the door or the advanced key (hold down).

Design

The sensor line of the sensor-controlled luggage compartment
release system consists of 2 coaxial wires.

646_067

Rear hatch power opening control unit
J938

66

Sensor line

646_068

Activation

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G750 G760

5

1

J938

Potential operating errors

detect both sensor lines (induction loops).

Key:

G750 Rear hatch power opening sender, in rear bumper
G760 Rear hatch power opening sender 2, in rear bumper
J938 Rear hatch power opening control unit
1 Sensor-, G750
2 Sensor+, G750
3 Sensor-, G760

5

4 Sensor+, G760
5 Shield

432

646_070

The leg must be reliably detectable by both grey detection areas.Potential operating errors usually occur when the system fails to

Other possible errors

The sensor-controlled rear hatch is not available or only available
to a limited extent in the following situations (examples):

• If the rear bumper is very dirty.

• If the rear bumper is wetted with salty water, e.g. after

driving on gritted roads.

critical

646_069

• If the luggage compartment lid is closed or opened directly

beforehand.

67

Garage door opener (HomeLink)

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Installation locations

The garage door opener control unitJ530 is attached to the vehicle
body at the rear left by means of a bracket specific to the AudiA4.
The control unit itself is a carry-over part from the AudiQ7(type4M).

The garage door opener programming aerial R278 for program­ming the handheld garage door sensor terminates inside the
AudiA4 (within the cable duct in the rear right heel panel area).

Garage door opener control unit
J530

System architecture

The electrical system control unit J519 the master control unit for
garage door operation control unit J530. The control unit J530
communicates with control unit J519 via LIN bus (LIN 2). The same
applies to the garage door operating unit E284 (integrated in
overhead module).

Convenience CAN

Electrical system
control unit
J519

LIN2

646_046

The garage door opener programming aerial R278 is connected to
garage door operation control unit J530. The garage door opener
programming aerial R278 is configured as a dipole antenna.

Garage door
operation control unit
J530

68

Garage door
operating unit
E284

Garage door opener
programming aerial
R278

646_048

Programming process

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As with the AudiQ7(type4M), there are two dierent processes
for programming both garage door opener systems for the new
AudiA4:

• a fixed code system

• a rolling code system

Both programing processes are MMI-controlled. The individual
steps are visualised on the MMI screen.

Vehicle settings

Program garage door opener

Clear programmed settings

Garage door opening

646_049

The two code systems are handled dierently. A programmed fixed
code system is ready for use straight after programming. In the
case of a rolling code system, on the other hand, the garage door
and the in-car HomeLink system, for example, still need to be
synchronised.

Service measurement data / diagnostic tester

The last 3 programming cycles of the sensor can be read out by
service personnel via the data blocks.
These 3 data blocks provide the mechanic with the following
information relating to the last 3 programing cycles:

• Frequency

• Manufacturer

• Fault status and modulation

• Programming timeout

• User abort

Other data blocks provide the mechanic with information about
the current country code and the system supply voltage.

• Speed information

• Aerial

• Status

• Channel

Note

It is recommended that two persons perform the adaption process, e.g. to synchronise the garage door drive with the
HomeLink system, as there is usually only a very small window available for synchronisation, e.g. between the garage door
opener and the garage door itself.

Note

Individual buttons can be reprogrammed using the menu navigation. This overwrites the previously stored value.
All programmed channels can be deleted with menu assistance.
Programming can be aborted at any time using the BACK button.

69

Head-up display

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Warnings, selected information from assistance systems and
navigation instructions can be projected onto the windscreen via
the head-up display (control unit for windscreen projection J898).

This information is displayed within the driver's field of vision. The
virtual image is only visible to the driver within a limited region of
the windscreen. The driver is able to discern a virtual image at a
distance of approximately 2.1 m (image viewing distance).

646_063

The control unit for windscreen projection J898 can be invoked via
the diagnostic tester using diagnostic code 82. J898 is integrated
in the vehicle electrics via the infotainment CAN.
The head-up display is attached to the module cross-member by
means of an adjustable bracket.

Windscreen projection button
E736

646_064

Example of a display on the head-up display

Operating and setting options for customers

• Switching the head-up display on/o

• Individual height adjustment of the projected image (on the

windscreen projection button E736, in the rotary light switch
module)

• Selection of information to be displayed (via MMI menu)

Setting options for service partners:

The control unit for windscreen projection J898 can be calibrated.
Calibration is necessary under the following conditions:

• The control unit for windscreen projection J898 has been
replaced.

• The windscreen has been removed and installed or replaced.

• Adjustment of display brightness level (via MMI menu)

• Image rotation to align the display with the horizontal (via

MMI menu)

• The event memory contains the entry
NO or INCORRECT BASIC SETTING / ADAPTION.

70

Self study programmes

Ξ Contents

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For more information about the technology of the AudiA4, please
refer to the following self study programmes.

Appendix

SSP286 New Data Bus Systems –
LIN, MOST, Bluetooth

Order number: 000.2811.06.20

SSP 634 Audi Q7 (type 4M)
Onboard power supply and networking

Order number: A15.5S01.19.20

TM

SSP 459 Audi A8’10
Onboard power supply and networking

Order number: A10.5S00.63.20

SSP 638 Audi Q7 (type 4M)
Convenience electronics

Order number: A15.5S01.25.20

SSP644 Audi A4 (type 8W)

Order number: A15.5S01.28.20

SSP647 Audi A4 (type 8W)
Infotainment and Audi connect

Order number: A15.5S01.29.20

71

Audi Vorsprung durch Technik

646

All rights reserved.
Technical specifications are
subject to change.

Copyright

AUDI AG

I/VK-35
[email protected]

AUDI AG

D-85045 Ingolstadt
Technical status 07/15

Printed in Germany
A15.5S01.31.20