eSelf Study Program 970563

The 2017 A4 Electronic and
Electrical Systems

i

Audi of America, LLC
Service Training
Created in the U.S.A.
Created 12/2015
Course Number 970563
©2015 Audi of America, LLC
All rights reserved. Information contained in this manual is based on
the latest information available at the time of printing and is subject to
the copyright and other intellectual property rights of Audi of America,
LLC., its affiliated companies and its licensors. All rights are reserved to
make changes at any time without notice. No part of this document
may be reproduced, stored in a retrieval system, or transmitted in any
form or by any means, electronic, mechanical, photocopying, recording
or otherwise, nor may these materials be modified or reposted to other
sites without the prior expressed written permission of the publisher.
All requests for permission to copy and redistribute information should
be referred to Audi of America, LLC.
Always check Technical Bulletins and the latest electronic service repair
literature for information that may supersede any information included
in this booklet.

This eSSP contains video links which you
can use to access interactive media.

Revision 1:12/2015
ii

Introduction .......................................................................................1
Voltage supply.....................................................................................2
Vehicle battery ........................................................................................................................................................... 2
Jump start terminal ................................................................................................................................................... 3
Power distribution ..................................................................................................................................................... 4
Fuses and relays ........................................................................................................................................................ 5
Aluminum wires ......................................................................................................................................................... 6

Networking..........................................................................................8
Installation locations of control modules ............................................................................................................... 8
Topology ...................................................................................................................................................................10
Bus systems used on the Audi A4 ..........................................................................................................................12

Control units..................................................................................... 14
Brief descriptions .....................................................................................................................................................14

Exterior lighting............................................................................... 37
Headlight variants ...................................................................................................................................................37
Xenon headlight .......................................................................................................................................................39
LED headlight ...........................................................................................................................................................41
Tail lights ..................................................................................................................................................................43
High-mounted brake light / license plate lights ...................................................................................................44
Interior lighting .......................................................................................................................................................45
Overhead module ....................................................................................................................................................49

Audi drive select............................................................................... 50
Functional characteristics .......................................................................................................................................50
Displays and operation ............................................................................................................................................50
Audi drive select function .......................................................................................................................................51
Functional features .................................................................................................................................................51
Anti-theft alarm .......................................................................................................................................................52
Central locking .........................................................................................................................................................54
Garage door opener (HomeLink) ............................................................................................................................56
Head-up display .......................................................................................................................................................58

Self-study programs......................................................................... 59
Knowledge assessment.................................................................... 60

This eSelf Study Program teaches a basic knowledge of the design and functions of new models,
new automotive components or technologies.
It is not a Repair Manual! All values given are intended as a guideline only.
For maintenance and repair work, always refer to the current technical literature.

Note

Reference

iii

iv

Introduction
The 2017 Audi A4 is the second Audi vehicle to adapt the
MLBevo (Modular Longitudinal Platform evolution). A fully
equipped A4 has approximately 90 control modules, many
of which exchange information with one another.
The FlexRay bus system is now used on an A4 model for the
first time. It helps ensure data is transmitted quickly and
securely. The key components on the FlexRay are the engine
control module, the transmission control module, a new
central suspension control module, the ESC, power steering
control module and ACC.
In addition to the FlexRay bus CAN bus systems (CAN =
controller area network) integrate the climate control system
and several assistance systems such as Audi side assist and
the surround cameras.

They also facilitate communication between the comfort/
convenience control modules, the infotainment modules
and central display and operating components such as the
MMI and Audi virtual cockpit. LIN buses (LIN = local interconnect network) complement the CAN buses by serving
less complex systems such as the interior lighting.
The Audi A4 now also has aluminum high-current wires
with diameters of 16 mm2, 35 mm2 and 50 mm2.
It is also the first Audi to use aluminum wires with diameters of 2.5 mm2, 4 mm2 and 6 mm2. Thanks to these modifications, the weight of the vehicle in this area has been
reduced by approximately 13 lb (5 kg) compared with the
previous model.

646_002

Learning objectives of this Self-Study Program:
Once you have completed this eSelf-Study Program program
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 installed
on the car?

• What are the tasks of the control modules in the car?
• What are the versions of the exterior lighting, and
how are the individual light functions implemented?

• Which bus systems are used in the Audi A4?
1

Voltage supply
Vehicle battery
The vehicle battery is housed centrally in the spare wheel
well. The main fuse panel as well as Battery Interrupt
Igniter N253 are mounted on the positive terminal. In the
event of a crash, N253 disconnects the main battery lead
from the vehicle electrical system.

Battery Monitoring Control Module J367 (BDM) is located
at the negative battery terminal.

Battery Monitoring Control Module
J367

Battery
A

Main fuse panel and Battery
Interrupt Igniter
N253
646_081

2

Jump start terminal
The positive jump start terminal is located under a red
plastic cover on the right hand side of the engine compartment. A negative terminal is attached directly to the body
at the right suspension strut tower.

These terminals should also be used for maintaining the
battery in the showroom or when performing diagnostic
work.

Positive Jump start terminal
Terminal 30 Wire Junction TV2
with fuses

Terminal 30 supply

Distribution supply line

Suppressor C24

Sealing cap

Ground terminal

Terminal 30 Wire Junction 2
TV22

Starter/alternator cable

Connection to Radiator Fan Control Module J293
(4-cylinder engines)
Connection to Secondary Air Injection Pump Relay J299

Connection to Radiator Fan Control Module 2 J671

646_082

3

Power distribution
This is a schematic diagram of the A4 power distribution
structure.

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

TV22

TV2

TV1*

SC

SB

Main fuse panel
SF

Key:
646_083

1
2
3
4
5
6

Not used in North American Region
Not used in North American Region
Connection to Radiator Fan Control Module J293
(4-cylinder engines)
Connection to Secondary Air Injection Pump Relay J299
Connection to Radiator Fan Control Module 2 J671
Connection to Radiator Fan Control Module J293

A
B
C

Battery
Starter motor
Alternator

4

J367
J500
N253
SB
SC
SF
TV1*
TV2
TV22

Battery Monitoring Control Module
Power Steering Control Module
Battery Interrupt Igniter
Fuse panel B, on the footrest
Fuse panel C, under instrument panel, right side
Fuse panel F, in luggage compartment on left side
Wire Junction, base of right ‘A’ pillar
Terminal 30 Wire Junction
Terminal 30 Wire Junction 2

*Not for North American Market

Fuses and relays
The fuses on the main fuse panel as well as distributors
TV1* and TV22 are labeled only "S" in the Wiring Diagrams.
This also applies to other individual fuses distributed
throughout the car.

Relay and fuse panel in
plenum chamber

Terminal 30 Wire Junction and
Terminal 30 Wire Junction 2 with
fuses

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

Distributor for Wire Junction
TV1* with fuses

Main battery lead

646_084

Fuse panel C on the dash
panel, driver side.
The fuses here are labelled
"SC" in the Wiring Diagrams

*Not for North American Market

Fuse panel B on the driver
side footrest.
The fuses here are labelled
"SB" in the Wiring Diagrams

Fuse panel F in the luggage
compartment, rear left.
The fuses here are labelled
"SF" in the Wiring Diagrams

Main fuse panel at
positive terminal of
vehicle battery

Battery Monitoring
Control Module J367 at
negative terminal of
vehicle battery

5

Aluminum wires
Main battery lead
The main positive battery cable in the Audi A4 is made of
aluminum like the Audi A8 where this was used for the first
time. The cable begins at the main fuse panel as a flexible
round cable. On the right hand-side of the luggage compartment, it is welded onto a flexurally rigid aluminum
ribbon cable.

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 start terminal in the engine compartment.
If defective, the battery cable can only be replaced. There is
no provision for repairs.

Wiring harness
A new feature is the use of aluminum wires with diameters
of 2.5 mm2, 4 mm2 and 6 mm2 in certain areas of the wiring
harness.

This helps save weight in the electrical system. Copper
wires with diameters from 1.5 mm2 to 6 mm2 are also used,
particularly in areas in which wires are subject to movement, for example, on the hood.

Repairing aluminum wires
A new tool, VAS 631 001 has been developed for repairing
aluminum wires.
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.

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.

Crimping pliers

Wire stripper

Heat shrink tubing

646_087

Crimp connector

6

Special crimp connectors are used for the repair of aluminum wires. These connectors ensure strain resistant connection of the aluminum wires. The supplied heat shrink
tubing reliably protects the joints against moisture.

Transition zone

A cut aluminum 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.

Insulation fitting

Wire crimping sleeve
with serrations and additive

Coding for wire diameter in crimping pliers

Code for wire diameter
(both sides)

646_088

Challenges in repairing aluminum wires:
1. The crimp connector must provide a strain resistant
connection.

2. The joint must be sealed.

To achieve a strain resistant connection with the aluminum
wires, the oxide layers on the individual strands of the
aluminum 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.

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

Oxide layer

Heat shrink tubing

646_090
646_089

Cable strand

Oxide layer broken by
serrations in connector

Heat shrink tubing
(after heat applied)

Reference
For a detailed description of how to repair aluminum wires, please refer to the Workshop Manual. At the vehicle introduction,
the aluminum wire repair tools can be rented from Equipment Solutions.
7

Networking
Installation locations of control modules
Some of the control modules shown in the overview are
optional and/or country-specific equipment.

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

J387

J428

J1023

A27

J794

J844

J685
J500

J217

E380

J587

R242

E87

J764
J898

J285

J527

J623
A31

J792

J104

J1018
J519
J850

J386

Key:
A27
A31

Right LED Headlamp Power Output Module 1
Left LED Headlamp Power Output Module 1

E87 Front A/C Display Control Head
E265 Rear A/C Display Control Head
E380 Multimedia System Control Head
J104
J136
J217
J234
J245
J285

8

ABS Control Module
Memory Seat/Steering Column Adjustment Control Module
Transmission Control Module
Airbag Control Module
Power Sunroof Control Module
Instrument Cluster Control Module

J386
J387
J393
J428
J492
J500
J519
J521
J525
J527
J533

Driver Door Control Module
Front Passenger Door Control Module
Comfort System Central Control Module
Distance Regulation Control Module
All Wheel Drive Control Module
Power Steering Control Module
Vehicle Electrical System Control Module 1
Front Passenger Memory Seat Control Module
Digital Sound System Control Module
Steering Column Electronics Control Module
Data Bus On Board Diagnostic Interface

J245

J927
J769

J649

J521

J492

J775

J234

J772

E265

J533

J136

J648

J393
J525

J770

J928
J926

644_113

J587
J623
J648
J649
J685
J764
J769
J770
J772
J775

Selector Lever Sensor System Control Module