Audi A8 1994 User manual

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤
Edition 05.2002
Service
Service Department. Technical Information

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
List of Workshop Manual Repair GroupsList of Workshop Manual
Repair GroupsList of Workshop Manual Repair Groups
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤
Repair Group
01 - Self-diagnosis
Technical information should always be available to the foremen and mechanics, because their careful
and constant adherence to the instructions is essential to ensure vehicle road-worthiness and safety. In
addition, the normal basic safety precautions for working on motor vehicles must, as a matter of course,
be observed.
Service
All rights reserved.
No reproduction without prior agreement from publisher.
Copyright © 2010 Audi AG, Ingolstadt A0050809820

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
Contents
01 - Self-diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
1 Dash panel insert self-diagnosis with service interval extension . . . . . . . . . . . . . . . . . . . . . .1
1.1 Dash panel insert self-diagnosis with service interval extension . . . . . . . . . . . . . . . . . . . . . .1
1.2 General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
1.3 Starting dash panel insert self-diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
1.4 Interrogate fault memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
1.5 Fault table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
1.6 Final control diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
1.7 Erase fault memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
1.8 End output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
1.9 Code control unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
1.10 Read measured value block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
1.11 Adaption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
1.12 Adaption channels 02 to 09 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
1.13 Adaption channels 18 to 33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
1.14 Adaption channels 40 to 48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
1.15 Adaption channels 60 to 62 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
1.16 Input values on dash panel insert replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
1.17 Resetting service display on completion of service work (without VAS 5051) . . . . . . . . . . . .68
1.18 Checking data exchange between control units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69
2 Immobilizer self-diagnosis - immobilizer III . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
2.1 Immobilizer self-diagnosis - immobilizer III . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
2.2 General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
2.3 Starting immobilizer self-diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74
2.4 Interrogate fault memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76
2.5 Fault table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77
2.6 Erase fault memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78
2.7 End output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80
2.8 Read measured value block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80
2.9 Adaption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84
2.10 Matching of vehicle keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84
2.11 Procedure in the event of loss of keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90
2.12 Adaption following replacement of dash panel insert . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91
2.13 Adaption following replacement of engine control unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .96
2.14 Adaption following replacement of dash panel insert and engine control unit . . . . . . . . . . . .100
2.15 Control unit release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .104
3 Cruise control system (CCS) self-diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .107
3.1 Cruise control system (CCS) self-diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .107
3.2 General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .107
3.3 Checking cruise control system (CCS) - petrol engines with electronic throttle . . . . . . . . . .107
3.4 Checking cruise control system (CCS) - diesel engines . . . . . . . . . . . . . . . . . . . . . . . . . . . .112
3.5 Wiring and component check using test box V.A.G 1598/31 . . . . . . . . . . . . . . . . . . . . . . . .115
3.6 Activating/deactivating cruise control system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .116
4 Acoustic Parking System (APS) self-diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .118
4.1 Acoustic Parking System (APS) self-diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .118
4.2 General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .118
4.3 Starting automatic parking system self-diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .118
4.4 Interrogate fault memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .120
4.5 Fault table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .121
4.6 Final control diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .126
4.7 Erase fault memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .128
4.8 End output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .129
4.9 Code control unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .130
4.10 Read measured value block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .132
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
Contents i

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with respect to the correctness of information in this document. Copyright by AUDI AG.
4.11 Adaption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .136
5 Automatic headlight range control self-diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145
5.1 Automatic headlight range control self-diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145
5.2 General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145
5.3 Starting automatic headlight range control self-diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . .146
5.4 Interrogate fault memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .147
5.5 Fault table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .149
5.6 Final control diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .151
5.7 Basic setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .153
5.8 Erase fault memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .155
5.9 End output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .156
5.10 Code control unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .157
5.11 Read measured value block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .159
6 Connecting vehicle diagnostic, testing and information system VAS 5051 . . . . . . . . . . . . . .162
6.1 Connecting vehicle diagnostic, testing and information system VAS 5051 . . . . . . . . . . . . . .162
6.2 Safety precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .162
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
ii Contents

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permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
01 - Self-diagnosis
1 - Dash panel insert self-diagnosis with service interval extension
1.1 - Dash panel insert self-diagnosis with service interval extension
1.2 - General information
Technical features of dash panel insert
The dash panel insert is equipped with a service interval extension facility. The dash panel insert evaluates the
service requirement for the vehicle concerned on the basis of various input variables, such as driving style or
oil consumption.
The conventional service indicator (with fixed intervals) indicated a due service at 15000 km or 12 months.
By means of suitable limit value programming, the service interval extension function is capable of simulating
the behaviour of the conventional service display.
For this purpose, the limit values are designed to be flexible.
Provision is also made for evaluation of the oil temperature sender. The service indication can then be displayed
later (max. 30000 km or 730 days) by means of appropriate adaption channels in the self-diagnostic function.
Two different dash panel inserts are fitted:
◆ Midline: With Minicheck system
◆ Highline: With driver information system (DIS)
The speedometer features a mileage counter and trip recorder LCD.
The rev counter features a clock/date LCD.
The warning lamps are integrated into the speedometer and rev counter.
The centre display presents a selection menu and the service indicator.
The menu is controlled from a function selector switch in the centre console.
For detailed information on the dash panel insert and the selection menu
=> Audi A8 Owner's Manual
The dash panel insert is controlled by a microprocessor and provided with comprehensive self-diagnosis. Fault
codes are stored in the fault memory of the dash panel insert if faults occur in system components. Faults can
be determined using the vehicle diagnostic, testing and information system VAS 5051.
"dEF" display on trip recorder
If control unit in dash panel insert detects a ROM fault, "dEF" is displayed on trip recorder.
- Replace dash panel insert in the event of "dEF" display.
=> Electrical System; Repair Group 90; Dash panel insert Dash panel insert
Notes on dash panel insert replacement
◆ Dash panel insert is not to be dismantled.
◆ If necessary, dash panel insert is to be replaced as part of exchange program.
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
1.1 - Dash panel insert self-diagnosis with service interval extension 1

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permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
◆ Complete damage report sheet and return together with dash panel insert.
◆ Original packaging must be used for return shipment.
1.3 - Starting dash panel insert self-diagnosis
Requirements:
• Vehicle diagnostic, testing and information system VAS 5051 connected up and vehicle self-diagnosis se‐
lected => Page 162
• Ignition on
Sequence of operations
-> Readout on VAS 5051:
- From list -1- select vehicle system "17 - Dash panel insert".
- Wait until next readout appears.
-> Readout on VAS 5051:
1 - Dash panel insert identification
2 - Immobilizer control unit identification => Page 3
Control unit identification (example)
Dash panel insert control unit identification (example)
17 - Dash panel insert Vehicle system
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
2 01 - Self-diagnosis

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permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
Dash panel insert control unit identification (example)
8L0919860A Part No.; Assignment
=> Parts List
DASH PANEL INSERT+IMMOBILIZER 1) VDO 2)
D.. 3)
1)
2)
3)
Component designation
Manufacturer designation
(M73 = Magneti Marelli; VDO = VDO)
Data level
Code 00142 Control unit coding (checking => Page 17 )
Dealership number 12345 Workshop code of VAS 5051 with which coding was last
performed
Immobilizer control unit identification (example)
WAUZZZ4DZYN000126 1) AUZ7Z0W0801181 2) 1)
2)
17-digit ident no. (chassis number) of vehicle (display as
of immobilizer III => Page 74 )
14-digit immobilizer identification no.
- Touch ▸ key.
-> Readout on VAS 5051:
1 - List of diagnostic functions:
Diagnostic functions Page
02 Interrogate fault memory 4
03 Final control diagnosis 12
04 Basic setting -
05 Erase fault memory 15
06 End output 17
07 Code control unit 17
08 Read measured value block 20
09 Read individual measured value -
10 Adaption 28
11 Login procedure -
Vehicle ident. no. transfer -
Release (PIN) -
Channel 50 adaption (PIN) -
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
1.3 - Starting dash panel insert self-diagnosis 3

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permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
1.4 - Interrogate fault memory
Sequence of operations
- Start dash panel insert self-diagnosis => Page 2 .
-> Readout on VAS 5051:
- From list -1- select diagnostic function "02 - Interrogate fault memory".
-> Readout on VAS 5051:
1 - Content of fault memory:
- 0 faults detected
Or
- X faults detected
2 - Fault
- Fault code
- Fault location
- Type of fault
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
4 01 - Self-diagnosis

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permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
A - Faults detected:
- Print out information on screen or self-diagnosis log.
- Terminate function "02 - Interrogate fault memory" by touching
◂ key.
-> Readout on VAS 5051:
- Eliminate fault(s) in line with fault table => Page 5 .
- Select diagnostic function "02 - Interrogate fault memory" again in list and erase fault memory => Page
15 .
- Select diagnostic function "06 - End output" in list => Page 17 .
B - No fault detected:
- Select diagnostic function "06 - End output" in list => Page 17 .
1.5 - Fault table
Notes:
◆ Faults occurring in monitored sensors or components are stored in fault memory together with an indication
of the type of fault.
◆ The fault table is arranged according to the 5-digit fault codes on the left.
◆ All static and sporadic faults are stored in the fault memory:
A fault is recognised as being static if it is present for at least 2 seconds (ambient temperature sender at
least 60 seconds, coolant temperature sender only after engine has been running for at least 30 minutes).
If a fault is then no longer present, it is stored as being sporadic and "sporadic" also appears on display.
◆ After switching on ignition, all faults present are set to sporadic and only stored as being static if they are
still present after checking.
◆ Sporadic faults are erased if they do not re-occur in the course of 50 driving cycles (ignition on for at least
5 minutes, vehicle speed greater than 30 km/h).
◆ Do not immediately replace components indicated as being defective by VAS 5051, but rather: Start by
checking wiring and connectors to these components in line with current flow diagram. Also use current flow
diagram to check earth connections. This is particularly important if faults are output as being "sporadic".
◆ When eliminating an open circuit in the event of a data bus fault, always remember to twist the two data
wires of the corresponding bus system together to prevent electromagnetic interference.
◆ On completion of repair work, fault memory is to be interrogated again and erased.
Readout on VAS 5051 Possible cause of trouble Remedy
00562
Oil level/temperature sender
-G266
- Open circuit/short to positive
- Short to earth
- Open circuit in wiring or short - Use current flow diagram to perform
fault-finding
=> Current Flow Diagrams, Electrical
Fault-finding and Fitting Locations bind‐
er
- Implausible signal - Oil level/oil temperature sender -
G266 defective
- Replace -G266
=> Electrical System; Repair Group 90;
Dash panel insert Dash panel insert
00667
Ambient temperature signal
- Open circuit/short to positive
- Short to earth
- Open circuit in wiring or short - Use current flow diagram to perform
fault-finding
=> Current Flow Diagrams, Electrical
Fault-finding and Fitting Locations bind‐
er
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
1.4 - Interrogate fault memory 5

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permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
Readout on VAS 5051 Possible cause of trouble Remedy
- Implausible signal 1) - Operating and display unit for air
conditioner/Climatronic -E87 defec‐
tive
- Interrogate air conditioner fault mem‐
ory
- Sender defective => Air conditioner; Repair Group 01; In‐
terrogate fault memory-
1) Incorrect display; can be ignored
Readout on VAS 5051 Possible cause of trouble Remedy
00668
Vehicle voltage terminal 30
- Signal too low*
*This fault may also be stored if starter has been
operated for more than 10 seconds.
- Battery discharged/defec‐
tive
- Short in vehicle electrical
system
- Battery voltage less than
9.5 V
- Alternator defective
- Charge/replace battery
=> Electrical System; Repair
Group 27; Battery Removing
and installing alternator
Repair short in vehicle electri‐
cal system
Readout on VAS 5051 Possible cause of trouble Remedy
00771
Fuel gauge sender -G
- Open circuit/short to positive
- Short to earth
- Open circuit in wiring or short be‐
tween dash panel insert and fuel
gauge sender -G or (4WD vehicles)
fuel gauge sender -2- -G169 or fuel
gauge sender -3- -G237
- Use current flow diagram to perform
fault-finding
=> Current Flow Diagrams, Electrical
Fault-finding and Fitting Locations bind‐
er
- Fuel gauge sender -G or (4WD ve‐
hicles) fuel gauge sender -2- -G169 or
fuel gauge sender -3- -G237 defective
- Replace -G or -G169 or -G237
=> Fuel Supply System - Petrol En‐
gines; Repair Group 20
Readout on VAS 5051 Possible cause of trouble Remedy
00779
Ambient temperature sensor
-G17
- Open circuit/short to positive
- Short to earth
- Open circuit in wiring or short - Use current flow diagram to per‐
form fault-finding
=> Current Flow Diagrams, Electri‐
cal Fault-finding and Fitting Loca‐
tions binder
- Vehicles with no air conditioner:
- Ambient temperature sensor -
G17 defective
- Replace -G17
=> Air conditioner; Repair Group 87;
Air conditioner control components
Air conditioner control components
00849
S-contact at ignition/starter switch -D
- Open circuit - Open circuit in wiring - Use current flow diagram to per‐
form fault-finding
=> Current Flow Diagrams, Electri‐
cal Fault-finding and Fitting Loca‐
tions binder
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
6 01 - Self-diagnosis

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permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
Readout on VAS 5051 Possible cause of trouble Remedy
- Ignition/starter switch -D defec‐
tive
- Replace ignition/starter switch -D
=> Electrical System; Repair Group
94; Servicing lock cylinder and igni‐
tion/starter switch Servicing lock cyl‐
inder and ignition/starter switch
Readout on VAS 5051 Possible cause of trouble Remedy
01039
Coolant temperature gauge sender -G2
- Open circuit/short to positive
- Short to earth
- Open circuit in wiring or short - Use current flow diagram to per‐
form fault-finding
=> Current Flow Diagrams, Electri‐
cal Fault-finding and Fitting Loca‐
tions binder
- Coolant temperature sender -
G2 defective
- Replace -G2
=> Petrol engines; Repair Group
24
Readout on VAS 5051 Possible cause of trouble Remedy
01300
Control unit for navigation system with CD drive -
J401
- No communication - CAN bus fault
- Open circuit in wiring
- Wiring damage
- Use current flow diagram to
perform fault-finding
=> Current Flow Diagrams,
Electrical Fault-finding and
Fitting Locations binder
Eliminate open circuit in wir‐
ing
- "1" not displayed in meas‐
ured value block => Page
28 for navigation system
with CD drive control unit
- -J401
- Dash panel insert adaption
not performed correctly
- Select adaption channel 62
and enter correct adaption
value => Page 65
- Control unit for navigation
system with CD drive -J401
defective
- Replace navigation system
control unit
=> Radio, Telephone and
Navigation System; Repair
Group 91; Navigation system
III (route navigation) (from Wk
27/99 onwards); Removing
and installing control unit for
navigation system with CD
drive -J401 Navigation sys‐
tem III (route navigation)
(from Wk 27/99 onwards);
Removing and installing con‐
trol unit for navigation system
with CD drive -J401
Readout on VAS 5051 Possible cause of trouble Remedy
01302
Telematics control unit
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
1.5 - Fault table 7

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
Readout on VAS 5051 Possible cause of trouble Remedy
- No communication - CAN bus fault
- Open circuit in wiring
- Wiring damage
- Use current flow diagram to perform
fault-finding
=> Current Flow Diagrams, Electrical
Fault-finding and Fitting Locations binder
Eliminate open circuit in wiring
- "1" not displayed in measured value block
140 for control unit=>Page 28
- Dash panel insert adaption not performed
correctly
- Select adaption channel 62 and enter
correct adaption value => Page 65
- Telematics control unit -J526 defective - Replace control unit
=> Radio, Telephone and Navigation
System; Repair Group 91; Telematics;
Removing and installing telephone/tele‐
matics control unit -J526 Telematics; Re‐
moving and installing telephone/telemat‐
ics control unit -J526
Readout on VAS 5051 Possible cause of trouble Remedy
01303
Telephone transmitter/receiver unit
- No communication - CAN bus fault
- Open circuit in wiring
- Voltage supply to telephone trans‐
mitter/receiver unit interrupted
- Use current flow diagram to per‐
form fault-finding
=> Current Flow Diagrams, Elec‐
trical Fault-finding and Fitting Lo‐
cations binder
Eliminate open circuit in wiring
- "1" not displayed in measured value
block 140 for control unit=>Page
28
- Dash panel insert adaption not per‐
formed correctly
- Select adaption channel 62 and
enter correct adaption value =>
Page 65
- Telephone transmitter/receiver unit
defective
- Replace telephone transmitter/
receiver unit
=> Radio, Telephone and Naviga‐
tion System; Repair Group 91; Tel‐
ematics; Removing and installing
telephone/telematics control unit -
J526 Telematics; Removing and
installing telephone/telematics
control unit -J526
Readout on VAS 5051 Possible cause of trouble Remedy
01304
Radio
- No communication - CAN bus fault
- Open circuit in wiring
- Wiring damage
- Use current flow diagram to perform fault-
finding
=> Current Flow Diagrams, Electrical
Fault-finding and Fitting Locations binder
Eliminate open circuit in wiring
- "1" not displayed in measured value block
140 for radio =>Page 28
- Dash panel insert adaption not performed
correctly
- Select adaption channel 62 and enter cor‐
rect adaption value => Page 65
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
8 01 - Self-diagnosis

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
Readout on VAS 5051 Possible cause of trouble Remedy
- Radio defective - Replace radio
=> Radio, Telephone and Navigation Sys‐
tems; Repair Group 91; Radio system; Re‐
moving and installing radio Radio system;
Removing and installing radio
Readout on VAS 5051 Possible cause of trouble Remedy
01311
Data bus information
- Defective - CAN bus fault
- Open circuit in wiring or short at con‐
trol unit in information (display) data
bus
- Use current flow diagram to perform
fault-finding
=> Current Flow Diagrams, Electrical
Fault-finding and Fitting Locations bind‐
er
- "1" not displayed in measured value
block 140 for control unit with CAN ca‐
pability =>Page 28
- Dash panel insert adaption not per‐
formed correctly
- Select adaption channel 62 and enter
correct adaption value => Page 65
- In one-wire operating mode - Data bus working only on one wire - Check data exchange => Page 69
Use current flow diagram to perform
fault-finding
=> Current Flow Diagrams, Electrical
Fault-finding and Fitting Locations bind‐
er
Readout on VAS 5051 Possible cause of trouble Remedy
01312
Drive train data bus
- Defective - CAN bus fault
- Open circuit in wiring or short at control
unit in drive train data bus
- Use current flow diagram to perform fault-
finding
=> Current Flow Diagrams, Electrical
Fault-finding and Fitting Locations binder
- "1" not displayed in measured value block
125 for control unit with CAN capability
=>Page 27
- The dash panel insert was not correctly
adapted
- Select adaption channel 60 and enter cor‐
rect adaption value => Page 62
Readout on VAS 5051 Possible cause of trouble Remedy
01314
Engine control unit
- No communication - CAN bus fault
- Open circuit in wiring or short
- Wiring damage
- Use current flow diagram to perform fault-
finding
=> Current Flow Diagrams, Electrical
Fault-finding and Fitting Locations binder
- "1" not displayed in measured value block
125 for engine control unit =>Page 27
- Dash panel insert adaption not performed
correctly
- Select adaption channel 60 and enter cor‐
rect adaption value => Page 62
- Engine control unit defective - Replacing engine control unit
=> Repair Group 23; of relevant engine
code
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
1.5 - Fault table 9

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
Readout on VAS 5051 Possible cause of trouble Remedy
01315
Gearbox control unit
- No communication - CAN bus fault
- Open circuit in wiring or short
- Wiring damage
- Use current flow diagram to perform fault-
finding
=> Current Flow Diagrams, Electrical
Fault-finding and Fitting Locations binder
- "1" not displayed in measured value block
125 for engine control unit =>Page 27
- Dash panel insert adaption not performed
correctly
- Select adaption channel 60 and enter cor‐
rect adaption value => Page 62
- Gearbox control unit defective - Replace gearbox control unit
=> Repair Group 01; of relevant gearbox
code
Readout on VAS 5051 Possible cause of trouble Remedy
01320
Climatronic control unit -J255
- No communication - CAN bus fault
- Open circuit in wiring or short
- Wiring damage
- Use current flow diagram to perform
fault-finding
=> Current Flow Diagrams, Electrical
Fault-finding and Fitting Locations
binder
- "1" not displayed in measured value
block 131 for air conditioner control unit
=>Page 27
- Dash panel insert adaption not per‐
formed correctly
- Select adaption channel 61 and enter
correct adaption value => Page 62
- Control unit defective - Replace Climatronic control unit
=> Air Conditioner; Repair Group 87
Readout on VAS 5051 Possible cause of trouble Remedy
01325
Tyre pressure monitor control unit
- No communication - CAN bus fault
- Open circuit in wiring or short
- Wiring damage
- Use current flow diagram to per‐
form fault-finding
=> Current Flow Diagrams, Electri‐
cal Fault-finding and Fitting Loca‐
tions binder
- "1" not displayed in measured value
block 130 for control unit=>Page
27
- Dash panel insert adaption not per‐
formed correctly
- Select adaption channel 66 and
enter correct adaption value =>
Page 62
- Control unit defective - Replace tyre pressure monitor
control unit
=> Running Gear, Front-wheel
Drive and Four-wheel Drive; Re‐
pair Group 44
Readout on VAS 5051 Possible cause of trouble Remedy
01327
Automatic parking system control unit
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
10 01 - Self-diagnosis

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
Readout on VAS 5051 Possible cause of trouble Remedy
- No communication - CAN bus fault
- Open circuit in wiring or short
- Wiring damage
- Use current flow diagram to per‐
form fault-finding
=> Current Flow Diagrams, Electri‐
cal Fault-finding and Fitting Loca‐
tions binder
- "1" not displayed in measured val‐
ue block 125 for engine control unit
=>Page 27
- Dash panel insert adaption not
performed correctly
- Select adaption channel 60 and
enter correct adaption value
=>Page 62
- Automatic parking system control
unit -J446 defective
- Replace automatic parking sys‐
tem control unit
=> Electrical System; Repair
Group 94; Servicing automatic
parking system; Removing and in‐
stalling automatic parking system
control unit -J446
Readout on VAS 5051 Possible cause of trouble Remedy
01336
Group convenience system data bus
- Defective - CAN bus fault
- Open circuit in wiring or short at
control unit in convenience system
data bus
- Use current flow diagram to per‐
form fault-finding
=> Current Flow Diagrams, Electri‐
cal Fault-finding and Fitting Loca‐
tions binder
- "1" not displayed in measured val‐
ue blocks 125 to 131 for control unit
with CAN capability =>Page 27
- Adaption to dash panel insert not
performed correctly
- Select adaption channel 61 and
enter correct adaption value =>
Page 63
- In one-wire operating mode - Data bus working only on one wire - Check data exchange => Page
69
Use current flow diagram to per‐
form fault-finding
=> Current Flow Diagrams, Electri‐
cal Fault-finding and Fitting Loca‐
tions binder
Readout on VAS 5051 Possible cause of trouble Remedy
01402
Data wire from navigation
- Implausible signal - Open circuit in clock, enable or data
wire
- Check data wires for damage
- Problem with interface between navi‐
gation system and dash panel insert
- Fault caused by electromagnetic inter‐
ference in or outside vehicle
- Check causes of electromagnetic inter‐
ference
=> Radio, Telephone, Navigation; Repair
Group 91; Navigation System Navigation
System
65535
Control unit defective - Dash panel insert defective - Replace dash panel insert
=> Electrical System; Repair Group 90;
Dash panel insert Dash panel insert
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
1.5 - Fault table 11

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
1.6 - Final control diagnosis
Notes:
◆ Final control diagnosis can only be performed with engine stopped and ignition switched on.
◆ If final control diagnosis detects a fault, locate and eliminate cause of problem.
"Final control diagnosis" function consecutively actuates the following dash panel insert control elements (if
fitted/coded):
Actuation sequence
1 Analog displays
2 Dash panel insert warning lamp test
3 Seat belt warning system warning lamp -K19
4 Gong
5 Segment test
6 Illumination/switches and instruments
Test requirement:
• Illumination on
Sequence of operations
- Start dash panel insert self-diagnosis => Page 2 .
-> Readout on VAS 5051:
- From list -1- select diagnostic function "03 - Final control diagnosis".
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
12 01 - Self-diagnosis

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
Actuation of analog displays
-> Readout on VAS 5051:
A - 1st control element in test
1 - Analog displays
The following tests are implemented simultaneously:
◆ Passage of coolant temperature gauge needle through entire display range
◆ Passage of rev counter needle through entire display range
◆ Passage of speedometer needle through entire display range
◆ Passage of fuel gauge needle through entire display range
The following fixed values are displayed on completion of the above process:
Coolant temperature gauge: 90 °C
Rev counter: 3000 rpm
Speedometer: 100 km/h
Fuel gauge: 1/2
Actuation of warning lamp test for dash panel insert
- Touch ▸ key.
-> Readout on VAS 5051:
A - 2nd control element in test
2 - Dash panel insert warning lamp test
◆ Warning lamps in dash panel insert are actuated
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
1.6 - Final control diagnosis 13

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
Actuation of seat belt warning system warning lamp
- Touch ▸ key.
-> Readout on VAS 5051:
A - 3rd control element in test
3 - Seat belt warning system warning lamp -K19
◆ Seat belt warning system warning lamp is actuated (lights)
Notes:
◆ Seat belt warning system warning lamp is only activated in the event of appropriate dash panel insert coding.
◆ Seat belt warning system warning lamp is not active if it is not called up in final control diagnostic function.
Actuation of gong
- Touch ▸ key.
-> Readout on VAS 5051:
A - 4th control element in test
4 - Gong
◆ Gong sounds intermittently
Actuation of segment test
- Touch ▸ key.
-> Readout on VAS 5051:
A - 5th control element in test
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
14 01 - Self-diagnosis

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
5 - Segment test
◆ All elements of multi-function display, clock/date display and mileage counter/trip recorder light-
Actuation of illumination/switches and instruments
- Touch ▸ key.
-> Readout on VAS 5051:
A - 6th control element in test
6 - Illumination/switches and instruments
◆ Dash panel insert illumination is dimmed, becomes brighter, is then dimmed again and finally returns to
original brightness level
- Touch ▸ key.
-> Readout on VAS 5051:
A - Control element test over
- Terminate function "03 - Final control diagnosis" by touching ◂ key.
1.7 - Erase fault memory
Note:
If fault memory cannot be erased, interrogate fault memory again and eliminate fault.
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
1.6 - Final control diagnosis 15

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
Requirements:
• Fault memory interrogated => Page 4
• All faults eliminated
Sequence of operations
After fault memory interrogation:
-> Readout on VAS 5051:
- From list -1- select diagnostic function "05 - Erase fault memory".
-> Readout on VAS 5051:
1 - - No readout (prior to erasing)
Or
-Fault memory erased
Note:
If the following message appears in display zone -1-: "Fault memory not yet interrogated", this means that
sequence of operations has not been precisely observed. Fault memory cannot be erased until it has been
interrogated.
2 - Note:
Is function to be implemented?
Note: Data will be erased!
- Touch "OK" key on display -2-.
- Terminate function "05 - Erase fault memory" by touching ◂ key.
- Interrogate fault memory again after performing repair work.
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
16 01 - Self-diagnosis