Audi TT 8 User Manual
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Service
Workshop Manual
Audi TT 1999 ➤
Running gear, self-diagnosis
Edition 07.2004
Service Department. Technical Information
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Service
List of Workshop Manual Repair GroupsList of Workshop Manual
Repair GroupsList of Workshop Manual Repair Groups
Re pa ir G ro up
01 - Self-diagnosis, electrical checks
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.
All rights reserved.
No reproduction without prior agreement from publisher.
Copyright © 2010 Audi AG, Ingolstadt A0057006120
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 TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
Contents
01 - Self-diagnosis, electrical checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1 Self-diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Basic notes on self-diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Function of the individual systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Safety precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.4 Requirements for test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.5 Fault finding procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.6 Road test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.7 Connecting vehicle diagnostic, testing and information system VAS 5051 A . . . . . . . . . . 7
2 CAN bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1 Testing a “two-wire data bus system” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3 ABS/EDL and ABS/EDL/TCS, ITT Mark 20 without ESP . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.1 Electrical/electronic components and fitting locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.2 Faults displayed by warning lamps in instrument cluster . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.3 Performing self-diagnosis on the ABS/EDL and ABS/EDL/TCS, ITT Mark 20 without ESP
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.4 Interrogating fault memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.5 Fault tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.6 Final control diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.7 Basic setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.8 Erasing fault memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.9 End output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.10 Renewing and coding control unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.11 Measured value block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3.12 Login procedure or coding II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
3.13 Electrical check of ABS/EDL and ABS/EDL/TCS ITT Mark 20 without ESP . . . . . . . . . . . . 47
3.14 Connecting adapter V.A.G 1598/21 (test box) to ABS with EDL control unit J104 . . . . . . 48
3.15 Test table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
4 ABS/EDL/TCS/ESP ITT Mark 20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.1 Retrofit installation of ESP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.2 Electrical/electronic components and fitting locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.3 Faults displayed by warning lamps in instrument cluster . . . . . . . . . . . . . . . . . . . . . . . . . . 62
4.4 Performing self-diagnosis of ABS/EDL/TCS/ESP ITT Mark 20 system . . . . . . . . . . . . . . . . 65
4.5 Interrogating fault memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
4.6 Fault tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
4.7 Final control diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
4.8 Basic setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
4.9 Performing zero compensation of steering angle sender G85 . . . . . . . . . . . . . . . . . . . . . . 99
4.10 Erasing fault memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
4.11 End output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
4.12 Renewing and coding control unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
4.13 Measured value block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
4.14 Login procedure or coding II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
4.15 Electrical check of ABS/EDL/TCS/ESP ITT MARK 20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
4.16 Connecting test box V.A.G 1598 A with adapter cable (47-pin) V.A.G 1598/33 to ABS with
EDL control unit J104 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
4.17 Test table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
5 ABS/ESP, MK 60 Continental Teves Mark 60; Electronic Stabilisation Program, Continental
Teves Mark 60 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
5.1 This self-diagnosis system is described exclusively in the “Guided fault finding” . . . . . . . . 133
Contents i
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Audi TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
ii Contents
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Running gear, self-diagnosis - Edition 07.2004
01 – Self-diagnosis, electrical checks
1 Self-diagnosis
1.1 Basic notes on self-diagnosis
♦ The control unit of a system with self-diagnosis function de‐
tects any faults or malfunctions during vehicle operation and
stores them in a fault memory. This information will remain
available even if the system voltage fails.
♦ The self-diagnosis function enables faults to be traced quickly
and efficiently. The self-diagnosis functions available can be
implemented via vehicle diagnostic, testing and information
system -VAS 5051 A- or vehicle diagnosis and service infor‐
mation system -VAS 5052- .
Note
Audi TT 1999 ➤
This Workshop Manual describes how to perform self-diagnosis
using vehicle diagnostic, testing and information system VAS 5051 A- .
♦ The respective control unit and the vehicle diagnostic, testing
and information system -VAS 5051 A- must be able to ex‐
change data in order to communicate with each other. The
diagnostic connector is the interface for communication be‐
tween the control unit and vehicle diagnostic, testing and
information system -VAS 5051 A- .
Fault detection by ABS with EDL control unit -J104-
♦ The control unit detects any faults which may occur during ve‐
hicle operation and stores them in a fault memory.
♦ To commence fault finding, initiate self-diagnosis and inter‐
rogate the stored faults. It is necessary to interrogate the fault
memories of all vehicle systems with self-diagnosis capability
since the ABS with EDL control unit -J104- exchanges data
with the engine control unit as well as the steering angle send‐
er -G85- and the four-wheel drive control unit -J492- (if fitted).
Select function “00 - Interrogating fault memory - Complete
system” ⇒ page 7 .If faults are stored in any other systems,
check whether the stored faults affect the ABS/EDL/TCS/ESP
system by referring to the respective fault tables.
♦ After evaluating all received data, the ABS with EDL control
unit -J104- distinguishes between sporadic faults (occurring
intermittently) and static faults (permanently present for a de‐
fined period), and stores these faults in an internal memory.
♦ If a fault occurs, it is initially stored as being static. If the fault
does not reoccur over a certain period of time or while the ve‐
hicle is driven a certain distance, it is then stored as sporadic
fault.
♦ When interrogating the fault memory, sporadic faults are
marked as “sporadic” on the display.
♦ A fault is also stored as sporadic if the ignition is switched off
and on again while the fault memory is being interrogated, or
if the fault memory is not erased after performing repairs.
♦ Sporadic faults are erased automatically if they do not occur
again within the next 50 vehicle starts and driving off sequen‐
ces (road speed greater than 20 km/h).
1. Self-diagnosis 1
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Audi TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
♦ The ABS with EDL control unit -J104- is able to detect whether
any of the required signals are not being transmitted via the
CAN bus.However, defective CAN bus wires (e.g. open circuit)
cannot be detected directly. The defective CAN bus wires can
only be traced after interrogating the fault memories of all con‐
trol units ⇒ page 9 .
♦ Sporadic faults affecting the CAN bus are erased automati‐
cally if they do not occur again within the next 15 vehicle starts
and driving off sequences (vehicle speed greater than 20 km/
h).
1.2 Function of the individual systems
1.2.1 Anti-lock brake system
The anti-lock brake system (ABS) prevents the wheels from lock‐
ing when the brakes are applied by the driver. Directional stability
and steerability are maintained in spite of high braking effect.
1.2.2 EDL - Electronic differential lock
The EDL system assists pulling away; it acts only on the front
wheels, even if the vehicle is equipped with four-wheel drive.An
electronically controlled brake application on the spinning driven
wheel provides a torque reaction point for the differential. This
enables the wheel with better traction to make use of the engine
power. The EDL is effective in both forwards and reverse direc‐
tions. The EDL control process is available up to a road speed of
80 km/h.
1.2.3 EBPD - Electronic brake pressure distri‐
bution
The Audi TT is not fitted with a mechanical brake pressure regu‐
lator. Specially developed software in the ABS with EDL control
unit -J104- provides electronic brake force distribution (EBPD)
and limits the brake pressure applied to the rear wheels.
1.2.4 TCS - Traction control system
♦ TCS (traction control system) is fitted only on vehicles with
front-wheel drive. The TCS limits the engine power to prevent
the driven wheels from spinning under acceleration. The sys‐
tem operates by reducing engine torque and is active at all
speeds. The EDL and TCS functions act together to assist ac‐
celeration. The warning lamp -1- flashes at a rate of three
times per second when the control function is working.
♦ The TCS requires an exchange of data between ABS with EDL
control unit -J104- and the engine control unit. The control
units communicate with each other. The data is transmitted via
CAN bus ⇒ page 9 .
♦ Depending on the engine version, the TCS also incorporates
an engine braking control (EBC). EBC prevents the driven
wheels from locking up due to excessive engine braking tor‐
que, for instance when the driver changes down from 3rd to
2nd gear. The engine braking effect is reduced via the elec‐
tronic idling stabilisation control.
♦ If required, the TCS function can be switched off (and on
again) by means of the button -2- (marked ASR) in the centre
of the dash panel. The TCS button has no influence on EBC.
The warning lamp lights up when the TCS is switched off. The
TCS is re-activated when the ignition is switched on again.
2 Rep. Gr.01 - Self-diagnosis, electrical checks
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Running gear, self-diagnosis - Edition 07.2004
1.2.5 ESP - Electronic Stabilisation Program
The ESP is based on the existing on-board safety systems ABS/
EDL and ABS/EDL/TCS, with a number of additional capabilities.
ESP enhances the degree of control in critical dynamic condi‐
tions. In addition to the existing safety systems, ESP further
reduces the risk of skidding and improves steerability.
Caution
However, ESP is not able to overcome the physical limits of
the available road adhesion.
♦ The ESP is designed to stabilise the dynamic handling re‐
sponse of the vehicle by counteracting any tendency towards
oversteer or understeer. The functions of EBPD, ABS, EDL
and TCS are incorporated in the control system. However, the
characteristic function of the ESP is controlled brake applica‐
tion at individual wheels.
♦ The ESP function relies on an exchange of signals between
ABS with EDL control unit -J104- and the engine control unit,
the steering angle sender -G85- and the four-wheel drive con‐
trol unit -J492- (if fitted). The data is transmitted via CAN bus
⇒ page 9 .
♦ If required, the TCS function and the ESP function can be
switched off (and on again) by means of the button -2- (marked
ASR) in the dash panel. The control unit ignores the position
of the ESP switch when the driver presses the brake pedal.
ESP will remain active at all times during braking. Both func‐
tions, TCS and ESP, will be activated again automatically the
next time the ignition is switched on.
♦ When the TCS and ESP function are deactivated, the ESP and
TCS warning lamp -K155- -item 1- in the instrument cluster
lights up. The warning lamp flashes at a rate of three times per
second when the control function is actually working.
Audi TT 1999 ➤
Examples:
In an oversteer condition, the rear of the vehicle tends to break
away. The vehicle rotates further about its vertical axis than is
required to maintain course through the corner. The system coun‐
teracts this moment of vehicle oversteer by applying a controlled
braking force at the outside front wheel -arrow-.
1. Self-diagnosis 3
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permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
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Audi TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
In an understeer condition the front end of the vehicle does not
follow the required corner radius. The vehicle breaks away to‐
wards the outside of the bend. The vehicle does not rotate far
enough about its vertical axis to maintain course through the cor‐
ner. The system increases the amount of rotation by applying a
controlled braking force at the inside rear wheel -arrow-.
1.3 Safety precautions
♦ The ABS/EDL/TCS and ESP are safety systems; knowledge
of the systems is essential for performing repair work
♦ Always switch off the ignition before carrying out installation
or repair work.
♦ Ensure that no brake fluid enters electrical connectors.
WARNING
♦ To avoid any risk of accident, observe the following pre‐
cautions when using test instruments while road testing
the vehicle:
Audi TT Coupé:
♦ Use only vehicle diagnostic, testing and information sys‐
tem -VAS 5051 A- or vehicle diagnosis and service infor‐
mation system -VAS 5052- to read measured value
blocks. The tester must always be secured on the rear
seat and operated from there by a second person.
♦ Due to the limited space, slide the front passenger's seat
forwards as far as it will go and (without pulling the release
lever) incline the backrest as far forwards as possible by
turning the adjuster knob. Do not operate the release lever
to tilt the backrest forward.
Audi TT Roadster:
♦ In the Audi TT Roadster, use only vehicle diagnosis and
service information system -VAS 5052- with the front pas‐
senger's airbag de-activated.
♦ Switch off the front passenger's airbag by means of the
key-operated switch in the glove box or via self-diagnosis
⇒ Body, self-diagnosis; Rep. Gr. 01 .
♦ Reactivate front passenger's airbag after testing is com‐
pleted.
♦ Do not drive the vehicle with the connector unplugged from the
control unit.
♦ During the final road test ⇒ page 6 , ensure that an ABS-
controlled brake application is performed at least once
⇒ page 4 .
1.4 Requirements for test
• When starting the self-diagnosis procedure, the vehicle must
be stationary and the ignition switched on (or engine running).
It is not possible to start self-diagnosis if the wheel speed is
4 Rep. Gr.01 - Self-diagnosis, electrical checks
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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.
Running gear, self-diagnosis - Edition 07.2004
above 2.75 km/h. Self-diagnosis will be terminated if road
speed exceeds 20 km/h.
• Power supply OK (min. 10.0 V).
• Fuses OK ⇒ Current flow diagrams, Electrical fault finding and
Fitting locations.
• Connector on ABS with EDL control unit -J104- correctly plug‐
ged-in (retainer is engaged).
• The tyres fitted to all wheels must be of the same (approved)
size; tyres inflated to prescribed pressure.
• Wheel speed sensors must be installed correctly ⇒ Brake
system; Rep. Gr. 45 .
• Mechanical/ hydraulic brake system components (including
brake light switch and brake lights) OK. Hydraulic connections
and pipes not leaking (visual check of hydraulic unit, brake
calipers, wheel cylinders, master brake cylinder).
• Wheel bearings and wheel bearing play OK.
• When testing the ABS/EDL/TCS and ESP systems, ensure
that the vehicle's electrics are not subjected to electromag‐
netic interference: keep the vehicle away from equipment with
a high current draw, such as electric welding units.
Audi TT 1999 ➤
1.5 Fault finding procedure
If a problem exists on the vehicle, perform the fault-finding pro‐
cedure in the following sequence:
– First switch on the ignition and observe the warning lamps.
This will give an initial indication of what to look for (vehicles
without ESP ⇒ page 14 , vehicles with ESP ⇒ page 62 ).
– Observe the test requirements detailed on ⇒ page 4 .
– Connect vehicle diagnostic, testing and information system -
VAS 5051 A- and select vehicle system “03 - Brake electron‐
ics” ⇒ page 7 .
– Check the control unit version ⇒ page 8 .
– Interrogate the fault memory (vehicles without ESP
⇒ page 17 , vehicles with ESP ⇒ page 65 ). If a fault is
present in the memory: print out the content of the fault mem‐
ory and then erase the fault memory.
– Conclude the transfer of data with the function “06 - End out‐
put”.
– Eliminate the fault using the fault tables.
– If a component is indicated as being defective, only renew it if
you are sure that the electrical wiring for that component is in
proper condition. The wiring must be able to transmit the nec‐
essary signals without interference or resistance. Check the
wiring for:
♦ Corrosion and loose contacts in the connectors and earth con‐
nections. If any of the plug contacts are bent, broken or cor‐
roded, use the wiring repair kit -VAS 1978- to fit new contacts.
♦ Open circuit in wiring or short circuit to positive/earth ⇒ Current
flow diagrams, Electrical fault finding and Fitting locations.
– Check that the connectors are plugged in correctly (with re‐
tainers engaged).
– After completing the repair, select vehicle system “03 - Brake
system” for a second time. Interrogate and erase fault mem‐
ory.
1. Self-diagnosis 5
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permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
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Audi TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
– Conclude the transfer of data with the function “06 - End out‐
put”.
– Switch off ignition and detach diagnostic connector.
– Perform a road test ⇒ page 6 to check the function of the
system. If any of the warning lamps light up during the road
test, repeat the fault finding procedure.
WARNING
If the connector is not plugged into the ABS with EDL control
unit -J104- when the vehicle is moving, this may result in a
spurious (non-existent) fault being registered in the fault mem‐
ory of another control unit. The function of the brake system
will be impaired. The brake pressure at the rear wheels is no
longer controlled by the electronic brake force distribution func‐
tion. This can result in excessive braking at the rear, and the
tail of the vehicle may break out unexpectedly.
Note
For information on repairing common faults, refer to ⇒ Technical
Service Handbook.
1.6 Road test
Certain faults will only be detected by the self-diagnosis when the
vehicle is moving. Perform a road test to check the function of the
system.
WARNING
♦ To avoid any risk of accident, observe the safety precau‐
tions when using test instruments while road testing the
vehicle ⇒ “1.3 Safety precautions”, page 4 .
♦ If you drive the vehicle after a fault has been detected by
the self-diagnosis bear in mind that there is a risk of acci‐
dent. The function of the brake system will be impaired.
The brake pressure at the rear wheels is no longer con‐
trolled by the electronic brake force distribution function.
This can result in excessive braking at the rear, and the
tail of the vehicle may break out unexpectedly.
♦ The ABS/ESP function is deactivated when using vehicle
diagnostic, testing and information system -VAS 5051 Ain the mode “vehicle self-diagnosis” while road testing the
vehicle. However, this is not indicated by illumination of
the warning lamps. Self-diagnosis of ABS with EDL control
unit -J104- is terminated if a road speed of 20 km/h is ex‐
ceeded.
– Maintain a speed above 60 km/h for a period of 30 seconds.
After ensuring that it is safe to do so, apply the brakes hard
enough to activate ABS-controlled braking. This can be felt
from the pulsation at the brake pedal.
1.6.1 Special feature for four-wheel drive ve‐
hicles with Haldex coupling
♦ The longitudinal acceleration sender -G251- must be deacti‐
vated when testing the brake system on test rollers (vehicles
without ESP ⇒ page 35 , vehicles with ESP ⇒ page 90 ).
6 Rep. Gr.01 - Self-diagnosis, electrical checks
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Running gear, self-diagnosis - Edition 07.2004
♦ After completion of the check, the longitudinal acceleration
sender -G251- must be reactivated by switching the ignition
off and back on again.
1.7 Connecting vehicle diagnostic, testing and information system -VAS 5051 A-
– With ignition switched off, connect vehicle diagnostic, testing
and information system -VAS 5051 A- with diagnosis lead VAS 5051 A/1- to diagnostic connection.
WARNING
Observe the relevant safety precautions ⇒ page 4 .
Note
Refer to ⇒ Operating instructions for vehicle diagnostic, testing
and information system -VAS 5051 A- if a fault is indicated on the
display.
Audi TT 1999 ➤
– Switch on ignition.
or
– Start engine.
Indicated on -VAS 5051 A- :
– Touch “Vehicle self-diagnosis” key.
Indicated on -VAS 5051 A- :
Note
Touching function “00 - Interrogate fault memory - complete sys‐
tem” in list -1- implements the automatic test sequence, i.e. fault
memory interrogation takes place for all vehicle systems with selfdiagnosis capability.
– From menu -1- select vehicle system “03 - Brake electronics”.
– Wait until next readout appears.
1. Self-diagnosis 7
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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.
Audi TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
Indicated on -VAS 5051 A- :
2 - Control unit identification of ABS with EDL control unit -J104- .
Control unit identification
: ABS with EDL control unit -J104- (example)
03 - Brake
Vehicle system
electronics
8N0907379.. Part No.; Allocation ⇒ Parts catalogue
ESP System designation
CAN Data bus (CAN)
Code number
241
Control unit code (checking: vehicles without
ESP ⇒ page 39 , vehicles with ESP
⇒ page 103 ).
Dealership
number 12345
Dealership identifier of -VAS 5051 A- with
which coding was last performed
If the display “vehicle system not available” appears in display
zone -1-:
– Check:
♦ Voltage supply to diagnosis connector ⇒ Current flow dia‐
grams, Electrical fault finding and Fitting locations.
♦ Wiring connection between diagnosis connector and ABS with
EDL control unit -J104- ⇒ Current flow diagrams, Electrical
fault finding and Fitting locations.
8 Rep. Gr.01 - Self-diagnosis, electrical checks
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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.
Running gear, self-diagnosis - Edition 07.2004
2 CAN bus
Data bus:
A data bus is a system for the transmission and distribution of
data signals.
CAN:
A Controller Area Network is a bus system working with two wires.
They are referred to as bus wires. The bus wires transmit data
signals in serial form (one after the other) to the control units con‐
nected to the system.
These control units communicate with each other (i.e. exchange
data) via the CAN bus.
2.1 Testing a “two-wire data bus system”
Special tools and workshop equipment required
♦ Vehicle diagnostic, testing and information system -VAS 5051
A-
Test sequence:
– Refer to the appropriate current flow diagram to check how
many control units are connected to the CAN bus.
– Connect vehicle diagnostic, testing and information system -
VAS 5051 A- ⇒ page 7 and select function “00 - Automatic test
sequence”. When doing this the ignition must be switched on.
– Before testing the data bus wires make sure that there are no
faults in any of the control units which are connected to the
data bus. If a fault exists, the communication with other the
control units is affected.
Note
Audi TT 1999 ➤
A fault existing in or related to one of the control units does not
affect the data bus system directly, but results from a malfunction
of some kind in one of the systems. This may be a defective sen‐
sor, for example. The result is that the sensor signal can no longer
be processed for transmission via the data bus. A malfunction of
this kind has an indirect effect on the data bus system, and will
upset the communication with other control units which require
the signal from the affected sensor.
Procedure if a fault exists:
– Rectify the fault first.
– Print out the list of faults and erase the fault memories of all
control units (refer to “Interrogating fault memory” and “Eras‐
ing fault memory” for the relevant control unit.
– Conclude the transfer of data with the function “06 - End out‐
put”.
– Rectify the faults as described in the fault tables in the relevant
Workshop Manual.
When all faults have been rectified:
– If communication between the control units is still not working
properly, test the data bus wires.
– Distinguish between two possible configurations when tracing
faults in the bus wires.
2. CAN bus 9
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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.
Audi TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
♦ Two control units communicating via a “Two-line bus system”
⇒ page 10 .
♦ Three or more control units communicating via a “Two-line bus
system” ⇒ page 11 .
2.1.1 Two control units communicating via a
“Two-line bus system”.
– Switch off ignition.
– Unplug multi-pin connectors at both control units.
– Check for an open circuit in the bus wires ⇒ Current flow dia‐
grams, Electrical fault finding and Fitting locations.
– Check for short circuit between the bus wires ⇒ Current flow
diagrams, Electrical fault finding and Fitting locations.
– Check for short to positive and short to earth in the bus wires.
If the cause of the fault cannot be found in the data bus wires:
– As a trial measure, renew the control unit which can be ex‐
changed with the least effort in terms of time and cost.
If the control unit communication via data bus is still not OK:
– Renew the second control unit.
10 Rep. Gr.01 - Self-diagnosis, electrical checks
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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.
Running gear, self-diagnosis - Edition 07.2004
2.1.2 Three or more control units communi‐
cating via a “Two-line bus system”.
Example 1:
The faults stored in the fault memories indicate that the control
unit -1- has no connection to control units -2- and -3-.
Control unit Faults stored in fault memory
-1- ♦ No message from control unit -2-
♦ No message from control unit -3-
-2- ♦ No message from control unit -1-
-3- ♦ No message from control unit -1-
– Switch off ignition.
– Unplug electrical connectors on control units linked by data
bus wires and check bus wires for open circuit ⇒ Current flow
diagrams, Electrical fault finding and Fitting locations.
Audi TT 1999 ➤
Example 2:
The faults stored in the fault memories indicate that the control
unit -2- does not communicate with control units -1- and -3-.
Control unit Faults stored in fault memory
-1- ♦ No message from control unit -2-
-2- ♦ No message from control unit -1-
♦ No message from control unit -3-
-3- ♦ No message from control unit -2-
– Switch off ignition.
– Unplug electrical connectors on control units linked by data
bus wires and check bus wires for open circuit ⇒ Current flow
diagrams, Electrical fault finding and Fitting locations.
Example 3:
The faults stored in the fault memories indicate that none of the
control units can transmit or receive.
Control unit Faults stored in fault memory
-1- ♦ Control unit defective
-2- ♦ Control unit defective
-3- ♦ Control unit defective
– Switch off ignition.
– Unplug electrical connectors on control units linked by data
bus wires and check bus wires for short circuit ⇒ Current flow
diagrams, Electrical fault finding and Fitting locations.
2. CAN bus 11
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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.
Audi TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
– Check the bus wires for short to positive and short to earth.
– If the cause of the fault “Control unit defective” cannot be found
in the data bus wires, check whether one of the control units
is responsible for causing the fault.
• Electrical connectors on all control unit that communicate via
the CAN data bus are unplugged.
• Ignition switched off
– Connect one of the control units.
– Connect vehicle diagnostic, testing and information system -
VAS 5051 A- ⇒ page 7 .
– Switch on ignition and select the relevant vehicle system.
– Interrogate and erase the fault memory of the control unit
which has been just connected.
– Terminate function “05 - Erasing fault memory” by touching
← key.
– Conclude the transfer of data with the function “06 - End out‐
put”.
– Switch the ignition off and then on again.
– Leave the ignition switched on for 10 seconds. Then interrog‐
ate the fault memory of the control unit that has just been
connected.
If the fault “control unit defective” is indicated:
– Renew the control unit which has just been connected.
If the fault “control unit defective” is not indicated:
– Connect the next control unit and repeat the procedure.
12 Rep. Gr.01 - Self-diagnosis, electrical checks
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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.
Running gear, self-diagnosis - Edition 07.2004
3 ABS/EDL and ABS/EDL/TCS, ITT
Mark 20 without ESP
♦ The Audi TT without ESP is equipped with the ABS/EDL ITT
Mark 20 system or the ABS/EDL/TCS ITT Mark 20 system.
♦ The data signals are transmitted via CAN bus.
Note
ESP may have been retrofitted by AUDI AG on vehicles not orig‐
inally equipped with this system ⇒ page 59 .
3.1 Electrical/electronic components and fitting locations
1 - Brake master cylinder and
brake servo
2 - Hydraulic control unit
❑ The hydraulic control
unit comprises the ABS
hydraulic pump -V64- ,
the ABS hydraulic unit N55- and the ABS with
EDL control unit -J104- .
❑ Fitting location: in en‐
gine compartment (leftside)
❑ Tested by self-diagno‐
❑ Only unplug 25-pin con‐
❑ Assignment of 25-pin
❑ Removing and installing
❑ Perform coding of ABS
3 - Traction control system
warning lamp -K86-
❑ Only on vehicles with
❑ Fitting location: in instru‐
❑ Function ⇒ page 14
4 - “Brake warning” symbol
❑ Appears in the display of
❑ Function ⇒ page 14
5 - ABS warning lamp -K47-
❑ Fitting location: in instrument cluster
❑ Function ⇒ page 14
sis
nector when the ignition
is switched off
connector ⇒ page 50
⇒ Brake system; Rep.
Gr. 45
with EDL control unit J104- after renewal
⇒ page 39
TCS
ment cluster
the driver information system
Audi TT 1999 ➤
3. ABS/EDL and ABS/EDL/TCS, ITT Mark 20 without ESP 13
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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.
Audi TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
6 - Rear left and rear right speed sensor and speed sensor rotor
❑ Rear left speed sensor -G46- and rear right speed sensor -G44❑ Removing and installing speed sensor, fitting speed sensor wires ⇒ Brake system; Rep. Gr. 45
❑ Checking speed sensor rotor ⇒ Brake system; Rep. Gr. 45
❑ Speed sensor rotor is welded to wheel hub; removing and installing wheel hub ⇒ Running gear, front-
wheel drive and four-wheel drive; Rep. Gr. 42
7 - Diagnosis connector
❑ Fitting location: in footwell (front left), next to release lever for bonnet.
8 - Diagnostics connection cover
9 - Brake light switch -F-
❑ Can be checked via reading measured value block ⇒ page 45
❑ Removing and installing ⇒ Brake system; Rep. Gr. 45
10 - Front left and front right speed sensor and speed sensor rotor
❑ Front left speed sensor -G47- and front right speed sensor -G45❑ Removing and installing speed sensor, fitting speed sensor wires ⇒ Brake system; Rep. Gr. 45
❑ Checking speed sensor rotor ⇒ Brake system; Rep. Gr. 45
❑ Speed sensor rotor is welded to wheel hub; removing and installing wheel hub ⇒ Running gear, front-
wheel drive and four-wheel drive; Rep. Gr. 40
11 - Longitudinal acceleration sender -G251-
❑ Four-wheel drive vehicles only
❑ Fitting location: on A-pillar (passenger side)
❑ Can be checked via reading measured value block ⇒ page 46
❑ Refer to ⇒ Brake system; Rep. Gr. 45 for removing and installing, then perform zero compensation in
basic setting ⇒ page 36
3.2 Faults displayed by warning lamps in in‐
strument cluster
1 - “Brake warning” symbol
2 - ABS warning lamp -K47-
3 - Handbrake warning lamp -K14-
4 - Traction control system warning lamp -K86- (only on vehi‐
cles with TCS)
“Brake warning”
symbol
On On On Test sequence after switching on ignition (first two sec‐
Off Off Off System OK (2 seconds after switching on ignition)
Off Off On TCS system failure or TCS system has been switched
Off Off flashes TCS control function is operating
Off On On ABS/EDL/TCS system failure (e.g. wheel speed sen‐
On On On ABS/EDL/TCS/EBPD system failure (e.g. several
ABS warning
lamp -K47-
Traction control
system warning
lamp -K86-
1)
Explanation
onds).
off via button; ABS, EDL and EBPD systems remain
functional.
sor defective), the EBPD remains fully functional.
wheel speed sensors defective)
14 Rep. Gr.01 - Self-diagnosis, electrical checks
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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.
Audi TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
“Brake warning”
symbol
ABS warning
lamp -K47-
Traction control
system warning
lamp -K86-
1)
Explanation
On Off Off Brake fluid level too low; all systems remain functional
1) Only on vehicles with TCS system
WARNING
There is a risk of accident if the ABS warning lamp -K47- and
the “brake warning symbol” both light up. The function of the
brake system will be impaired. As the brake pressure is no
longer controlled by the electronic brake force distribution the
rear wheels tend to brake excessively. Due to this the rear of
the vehicle may break away unexpectedly.
The ABS warning lamp -K47- -item 2- lights up during the test
sequence (self-test)
The system runs through an automatic test sequence when the
ignition is switched on: the ABS warning lamp -K47- is activated
by the ABS with EDL control unit -J104- and lights up for 2 sec‐
onds. During this period the control unit tests the following func‐
tions via self-test.
♦ The voltage supply is checked (min. 10.0 Volt).
♦ The control unit including the valve windings is checked.
♦ A speed sensor check (electrical test) is carried out; this is only
completed at 20 km/h.
♦ Control unit code is checked.
If the system does not perform the test sequence:
– Check voltage supply of ABS with EDL control unit -J104-
(perform electrical check, step 3 ⇒ page 51 ).
The ABS warning lamp -K47- -item 2- stays on after the test se‐
quence is completed
If a fault affecting only the anti-lock brake system is detected by
self-diagnosis, the ABS is switched off. The conventional brake
system remains fully functional.
The causes of the fault may be as follows:
♦ Voltage supply is below 10 Volts.
♦ A fault exists which affects only the ABS.
♦ A sensor fault has occurred after the last start (sporadic fault).
In this case the ABS warning lamp goes out automatically after
the vehicle is started again and the road speed exceeds 20 km/
h.
♦ Connection between ABS with EDL control unit -J104- and in‐
strument cluster is faulty or instrument cluster faulty (perform
electrical check, step 14 ⇒ page 55 ).
3. ABS/EDL and ABS/EDL/TCS, ITT Mark 20 without ESP 15
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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.
Audi TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
The ABS warning lamp -K47- -item 2- goes out after the test se‐
quence is completed,, but “brake warning symbol” -1- remains on
All systems remain functional.
The causes of the fault may be as follows:
♦ Brake fluid level too low.
♦ Fault in instrument cluster ⇒ Electrical system, self-diagnosis;
Rep. Gr. 01 or ⇒ Current flow diagrams, Electrical fault finding
and Fitting locations.
The ABS warning lamp -K47- -item 2- stays on after the test se‐
quence is completed and “brake warning symbol” -1- lights up
when vehicle speed first exceeds 10 km/h or engine speed first
exceeds 2000 rpm
The ABS system is defective and the EBPD system deactivated.
WARNING
There is a risk of accident if the ABS warning lamp -K47- and
the “brake warning symbol” both light up.The function of the
brake system will be impaired. As the brake pressure is no
longer controlled by the electronic brake force distribution the
rear wheels tend to brake excessively.Due to this the rear of
the vehicle may break away unexpectedly.
The causes of the fault may be as follows:
♦ The control unit is not coded (Code 00000), or is incorrectly
coded. In this case the ABS warning lamp -K47- will flash at a
rate of once per second. The “brake warning” symbol will also
flash when vehicle speed first exceeds 10 km/h or engine
speed first exceeds 2000 rpm after the ignition is switched on.
♦ A fault exists which affects the ABS and EBPD.
Note
If the ABS warning lamp -K47- and the “brake warning” symbol
do not light up but the brake system is not fully functional, the fault
must be traced in the conventional brake system ⇒ Brake system;
Rep. Gr. 46 and ⇒ Brake system; Rep. Gr. 47 .
Traction control system warning lamp -K86- -item 1- does not light
up after TCS is deactivated by pressing the traction control sys‐
tem switch -E132- -item 2-.
The causes of the fault may be as follows:
♦ Traction control system warning lamp -K86- defective (perform
electrical check, step 17 ⇒ page 57 ).
♦ Traction control system switch -E132- defective (perform elec‐
trical check, step 17 ⇒ page 57 and step 18 ⇒ page 57 ).
♦ Open circuit in vehicle power supply and wiring from ABS with
EDL control unit -J104- to instrument cluster (perform electri‐
cal check, step 17 ⇒ page 57 and step 18 ⇒ page 57 .
♦ Short circuit to positive in wiring from ABS with EDL control
unit -J104- to instrument cluster (perform electrical check, step
17 ⇒ page 57 and step 18 ⇒ page 57 ).
16 Rep. Gr.01 - Self-diagnosis, electrical checks
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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.
Running gear, self-diagnosis - Edition 07.2004
Traction control system warning lamp -K86- lights continuously
after ignition is switched on, and none of the malfunctions above
occur
The cause of the fault may be as follows:
♦ Short circuit to earth in wiring from ABS with EDL control unit
-J104- to instrument cluster (activation of TCS warning lamp)
(perform electrical check, step 17 ⇒ page 57 and step 18
⇒ page 57 ).
Vehicle with ABS/EDL has no EDL function
A possible cause of this fault is that the brake light switch is not
functioning. Check “measured value block 003” ⇒ page 45 .
Renewing brake light switch ⇒ Brake system; Rep. Gr. 45 .
3.3 Performing self-diagnosis on the ABS/ EDL and ABS/EDL/TCS, ITT Mark 20 without ESP
List of available functions
– With ignition switched off, connect vehicle diagnostic, testing
and information system -VAS 5051 A- with diagnosis lead VAS 5051 A/1- to diagnosis connector and select vehicle
system “03 - Brake electronics” ⇒ page 7 .
The following functions are available from the list -1-:
Audi TT 1999 ➤
Functions Page
02 Interrogate fault memory ⇒ page 17
03 Final control diagnosis ⇒ page 25
04 Basic setting ⇒ page 32
05 Erase fault memory ⇒ page 38
06 End output ⇒ page 39
07 Code control unit ⇒ page 39
08 Read measured value block ⇒ page 42
11
Login procedure/encoding II
2) The login procedure/encoding II is only required on four-wheel drive vehicles.
2)
⇒ page 46
The other functions displayed are currently not available, or can
be disregarded.
3.4 Interrogating fault memory
– Connect vehicle diagnostic, testing and information system -
VAS 5051 A- ⇒ page 7 and select vehicle system “03 - Brake
electronics”. When doing this the ignition must be switched on.
Indicated on -VAS 5051 A- :
– From list -1- select function “02 - Interrogate fault memory”.
3. ABS/EDL and ABS/EDL/TCS, ITT Mark 20 without ESP 17
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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.
Audi TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
Indicated on -VAS 5051 A- :
-1- Content of fault memory No faults detected
or
X faults detected
-2- Fault Fault code
Fault location
Type of fault
A - If a fault was detected:
– Print out information on screen or self-diagnosis log.
– Terminate function “02 - Interrogate fault memory” by touching
← key.
Indicated on -VAS 5051 A- :
– Rectify fault(s) according to fault tables ⇒ page 18 .
– From list -1- select function “02 - Interrogate fault memory” and
erase fault memory ⇒ page 38 .
– From list -1- select function “06 - End output” ⇒ page 39 .
– Perform road test and interrogate fault memory again.
B - If no fault was detected:
– Terminate function “02 - Interrogate fault memory” by touching
← key.
– Select function “06 - End output” from list ⇒ page 39 .
3.5 Fault tables
Note
♦
The following table includes all faults which can be detected
by the ABS with EDL control unit -J104- and displayed by VAS 5051 A- when interrogating the fault memory.
♦
The contents of the fault memory remains stored until the
memory is erased; Erasing fault memory ⇒ page 38 .
♦
Faults are listed according to a 5-digit fault code, which ap‐
pears in the left-hand column of the fault table.
♦
Sporadic (intermittent) faults are identified as such by the word
“sporadic” appearing on the display.
♦
Check wiring and connectors going to the relevant compo‐
nents according to current flow diagram before renewing com‐
ponents indicated as faulty by -VAS 5051 A- . Also check earth
connections according to current flow diagram. This is partic‐
ularly important if faults are indicated as being “sporadic”.
Fault 00283
Display on -
VAS 5051 A-
00283
Front left speed sensor -G47-
♦ Open circuit, loose contact or short to
Possible cause of fault Fault remedy
positive or earth in speed sensor wire or
speed sensor
– Perform electrical check, step 6
⇒ page 52 and step 10 ⇒ page 54
♦ Speed sensor winding defective
18 Rep. Gr.01 - Self-diagnosis, electrical checks
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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.
Audi TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
Display on -
VAS 5051 A-
♦ Speed sensor or rotor damaged – Check speed sensor and rotor ⇒ Brake
♦ ABS with EDL control unit -J104- defec‐
tive
00283
Front left speed sensor -G47Mechanical fault
• This fault is
only detec‐
♦ Excessive air gap between speed sensor
and rotor.
ted above 20
km/h (carry
out test
drive).
♦ Outlet valves in hydraulic unit defective – Check hydraulic unit in final control diag‐
00283
Front left speed sensor -G47Signal outside tolerance
• This fault is
only detec‐
ted above 20
km/h (carry
out test
♦ Open circuit, loose contact or short to
positive or earth in speed sensor wire or
speed sensor
♦ Speed sensor winding defective
drive).
♦ Electrical interference from external in‐
terference sources (high frequency radi‐
ation, e.g. non-insulated ignition cable)
Possible cause of fault Fault remedy
system; Rep. Gr. 45
– Remove hydraulic control unit, renew
control unit ⇒ Brake system; Rep. Gr.
45 , then code control unit ⇒ page 39
– Check installation of speed sensor and
rotor ⇒ Brake system; Rep. Gr. 45
nosis ⇒ page 25
– Perform electrical check, step 6
⇒ page 52 and step 10 ⇒ page 54
– Read measured value block 001
⇒ page 44
♦ Excessive air gap between speed sensor
and rotor.
♦ Speed sensor or rotor damaged – Check speed sensor and rotor ⇒ Brake
Fault 00285
Display on -
Possible cause of fault Fault remedy
VAS 5051 A-
00285
Front right speed sensor -G45-
♦ Open circuit, loose contact or short to
positive or earth in speed sensor wire or
speed sensor
♦ Speed sensor winding defective
♦ Speed sensor or rotor damaged – Check speed sensor and rotor ⇒ Brake
♦ ABS with EDL control unit -J104- defec‐
tive
00285
Front right speed sensor -G45Mechanical fault
– Check installation of speed sensor and
rotor ⇒ Brake system; Rep. Gr. 45
system; Rep. Gr. 45
– Perform electrical check, step 5
⇒ page 52 and step 9 ⇒ page 54
system; Rep. Gr. 45
– Remove hydraulic control unit, renew
control unit ⇒ Brake system; Rep. Gr.
45 , then code control unit ⇒ page 39
3. ABS/EDL and ABS/EDL/TCS, ITT Mark 20 without ESP 19
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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.
Audi TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
Display on -
Possible cause of fault Fault remedy
VAS 5051 A-
• This fault is
only detec‐
♦ Excessive air gap between speed sensor
and rotor.
ted above 20
km/h (carry
out test
drive).
♦ Outlet valves in hydraulic unit defective – Check hydraulic unit in final control diag‐
00285
Front right speed sensor -G45Signal outside tolerance
• This fault is
only detec‐
ted above 20
km/h (carry
out test
♦ Open circuit, loose contact or short to
positive or earth in speed sensor wire or
speed sensor
♦ Speed sensor winding defective
drive).
♦ Electrical interference from external in‐
terference sources (high frequency radi‐
ation, e.g. non-insulated ignition cable)
♦ Excessive air gap between speed sensor
and rotor.
– Check installation of speed sensor and
rotor ⇒ Brake system; Rep. Gr. 45
nosis ⇒ page 25
– Perform electrical check, step 5
⇒ page 52 and step 9 ⇒ page 54
– Read measured value block 001
⇒ page 44
– Check installation of speed sensor and
rotor ⇒ Brake system; Rep. Gr. 45
♦ Speed sensor or rotor damaged – Check speed sensor and rotor ⇒ Brake
Fault 00287
Display on -
VAS 5051 A-
00287
Rear right speed sensor -G44-
♦ Open circuit, loose contact or short to
positive or earth in speed sensor wire or
speed sensor
♦ Speed sensor winding defective
♦ Speed sensor or rotor damaged – Check speed sensor and rotor ⇒ Brake
♦ ABS with EDL control unit -J104- defec‐
tive
00287
Rear right speed sensor -G44Mechanical fault
• This fault is
only detec‐
♦ Excessive air gap between speed sensor
and rotor.
ted above 20
km/h (carry
out test
drive).
system; Rep. Gr. 45
Possible cause of fault Fault remedy
– Perform electrical check, step 7
⇒ page 53 and step 11 ⇒ page 54
system; Rep. Gr. 45
– Remove hydraulic control unit, renew
control unit ⇒ Brake system; Rep. Gr.
45 , then code control unit ⇒ page 39
– Check installation of speed sensor and
rotor ⇒ Brake system; Rep. Gr. 45
♦ Outlet valves in hydraulic unit defective – Check hydraulic unit in final control diag‐
00287
Rear right speed sensor -G44Signal outside tolerance
20 Rep. Gr.01 - Self-diagnosis, electrical checks
nosis ⇒ page 25
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 TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
Display on -
VAS 5051 A-
• This fault is
only detec‐
ted above 20
km/h (carry
out test
♦ Open circuit, loose contact or short to
positive or earth in speed sensor wire or
speed sensor
♦ Speed sensor winding defective
drive).
♦ Electrical interference from external in‐
terference sources (high frequency radi‐
ation, e.g. non-insulated ignition cable)
♦ Excessive air gap between speed sensor
and rotor.
♦ Speed sensor or rotor damaged – Check speed sensor and rotor ⇒ Brake
Fault 00290
Display on -
VAS 5051 A-
00290
Rear left speed sensor -G46-
♦ Open circuit, loose contact or short to
positive or earth in speed sensor wire or
speed sensor
♦ Speed sensor winding defective
♦ Speed sensor or rotor damaged – Check speed sensor and rotor ⇒ Brake
♦ ABS with EDL control unit -J104- defec‐
tive
00290
Rear left speed sensor -G46Mechanical fault
• This fault is
only detec‐
♦ Excessive air gap between speed sensor
and rotor.
ted above 20
km/h (carry
out test
drive).
Possible cause of fault Fault remedy
– Perform electrical check, step 7
⇒ page 53 and step 11 ⇒ page 54
– Read measured value block 001
⇒ page 44
– Check installation of speed sensor and
rotor ⇒ Brake system; Rep. Gr. 45
system; Rep. Gr. 45
Possible cause of fault Fault remedy
– Perform electrical check, step 8
⇒ page 53 and step 12 ⇒ page 55
system; Rep. Gr. 45
– Remove hydraulic control unit, renew
control unit ⇒ Brake system; Rep. Gr.
45 , then code control unit ⇒ page 39
– Check installation of speed sensor and
rotor ⇒ Brake system; Rep. Gr. 45
♦ Outlet valves in hydraulic unit defective – Check hydraulic unit in final control diag‐
♦ Excessive air gap between speed sensor
and rotor.
00290
Rear left speed sensor -G46Signal outside tolerance
• This fault is
only detec‐
ted above 20
km/h (carry
out test
♦ Open circuit, loose contact or short to
positive or earth in speed sensor wire or
speed sensor
♦ Speed sensor winding defective
drive).
nosis ⇒ page 25
– Check installation of speed sensor and
rotor ⇒ Brake system; Rep. Gr. 45
– Perform electrical check, step 8
⇒ page 53 and step 12 ⇒ page 55
3. ABS/EDL and ABS/EDL/TCS, ITT Mark 20 without ESP 21
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 TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
Display on -
VAS 5051 A-
♦ Electrical interference from external in‐
terference sources (high frequency radi‐
ation, e.g. non-insulated ignition cable)
♦ Excessive air gap between speed sensor
and rotor.
♦ Speed sensor or rotor damaged – Check speed sensor and rotor ⇒ Brake
Fault 00668
Display on -
VAS 5051 A-
00668
Vehicle voltage, terminal 30
Signal outside tolerance
♦ Fuse defective
♦ Open circuit or short circuit to earth or
positive in voltage supply wiring
Possible cause of fault Fault remedy
– Read measured value block 001
⇒ page 44
– Check installation of speed sensor and
rotor ⇒ Brake system; Rep. Gr. 45
system; Rep. Gr. 45
Possible cause of fault Fault remedy
– Perform electrical check, step 1
⇒ page 51 and step 2 ⇒ page 51
Fault 01044
Display on -
VAS 5051 A-
01044
Control unit incorrectly coded
♦ An incorrect code number has been en‐
tered
♦ Coding bridge in wiring harness dam‐
aged
Fault 01130
Display on -
VAS 5051 A-
01130
ABS operation
Signal outside tolerance
• This fault is
only detec‐
ted above 20
km/h (carry
out test
drive).
♦ Electrical interference from external in‐
terference sources (high frequency radi‐
ation, e.g. non-insulated ignition cable)
♦ Open circuit, loose contact or short to
positive or earth in wiring
Possible cause of fault Fault remedy
– Check code ⇒ page 39
– Check wires in wiring harness; perform
electrical check, test step 13
⇒ page 55
Possible cause of fault Fault remedy
– Check all wiring and connections for
short to positive or earth.
– Erase fault memory
– Perform test drive at more than 20 km/h
22 Rep. Gr.01 - Self-diagnosis, electrical checks
– Interrogate fault memory again
If the fault is not rectified:
– Remove hydraulic control unit, renew
control unit ⇒ Brake system; Rep. Gr.
45 , then code control unit ⇒ page 39
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.
Fault 01276
Audi TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
Display on -
Possible cause of fault Fault remedy
VAS 5051 A-
01276
ABS hydraulic pump -V64Signal outside tolerance
• This fault is
only detec‐
ted above 20
km/h (carry
♦ Open circuit or short circuit to earth or
positive in internal wiring: ABS with EDL
control unit -J104- / ABS hydraulic pump
-V64out test
drive).
♦ ABS with EDL control unit -J104- defec‐
tive
♦ Pump motor defective – Renew hydraulic control unit ⇒ Brake
Fault 01279
Display on -
VAS 5051 A-
01279
Longitudinal acceleration sender -G251-
Possible cause of fault Fault remedy
3)
Electrical fault in circuit
♦ Open circuit, loose contact or short to
positive or earth in wiring
– Check ABS hydraulic pump -V64- via fi‐
nal control diagnosis ⇒ page 25
If ABS hydraulic pump -V64- starts running
during final control diagnosis:
– Perform electrical check, test step 1
⇒ page 51
– Check all wiring and connections for
short to positive or earth according to cur‐
rent flow diagram.
– Remove hydraulic control unit, renew
control unit ⇒ Brake system; Rep. Gr.
45 , then code control unit ⇒ page 39
system; Rep. Gr. 45
– Perform electrical check, test step 19
⇒ page 58
♦ Installation position of longitudinal accel‐
eration sender -G251- not OK
♦ Longitudinal acceleration sender -G251-
defective
3) Four-wheel drive vehicles only.
Fault 01312
Display on -
VAS 5051 A-
01312
Drive train data bus
defective
4)
♦ ABS with EDL control unit -J104- incor‐
rectly coded
♦ Engine control unit incorrectly coded – Check coding of engine control unit ⇒
– Check installation position ⇒ Brake sys‐
tem; Rep. Gr. 45
– Read measured value block 006
⇒ page 46
– Renew sender ⇒ Brake system; Rep. Gr.
45 , then perform zero compensation in
basic setting ⇒ page 36
Possible cause of fault Fault remedy
– Check code ⇒ page 39
Motronic injection and ignition system;
Rep. Gr. 01
3. ABS/EDL and ABS/EDL/TCS, ITT Mark 20 without ESP 23
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 TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
Display on -
Possible cause of fault Fault remedy
VAS 5051 A-
4) If fault is displayed as sporadic fault: can occur when vehicle is started. This is
not a fault in the system; ignore and erase fault memory.
♦ Faults in CAN bus wiring – Check CAN bus wiring between engine
Fault 01314
Display on -
Possible cause of fault Fault remedy
VAS 5051 A-
01314
Engine control unit
No communication
• Signals are
transmitted
between
5)
When displayed as static fault:
♦ ABS with EDL control unit -J104- or en‐
gine control unit not CAN compatible
ABS with
EDL control
unit -J104and engine
♦ Fault in engine control unit – Interrogate fault memory of engine con‐
control unit
via CAN data
bus
When displayed as static and sporadic fault:
♦ Faults in CAN bus wiring
♦ High and Low CAN bus wiring inter‐
changed
♦ The output of one of the control units
communicating via the CAN bus is de‐
fective.
control unit and ABS with EDL control unit
-J104- ⇒ page 9
– Refer to control unit identification of ABS
with EDL control unit -J104- ⇒ page 8 and
engine control unit to check that correct
control units are installed. Allocation ⇒
Parts catalogue
trol unit ⇒ Motronic injection and ignition
system; Rep. Gr. 01 , rectify fault if nec‐
essary and erase fault memory
– Check CAN bus wiring between engine
control unit and ABS with EDL control unit
-J104- ⇒ page 9
– Check CAN Bus wiring for interchanged
connections according to current flow di‐
agram
– Check CAN bus wiring ⇒ page 9
5) Only on vehicles with TCS system
Fault 01324
Display on -
Possible cause of fault Fault remedy
VAS 5051 A-
01324
Four-wheel drive control unit -J492No communication
6) Four-wheel drive vehicles only.
6)
♦ Faults in CAN bus wiring – Check CAN bus wiring ⇒ page 9
Fault 65535
Display on -
Possible cause of fault Fault remedy
VAS 5051 A-
65535
Control unit defective
24 Rep. Gr.01 - Self-diagnosis, electrical checks
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 TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
Display on -
Possible cause of fault Fault remedy
VAS 5051 A-
♦ ABS with EDL control unit -J104- defec‐
tive
3.6 Final control diagnosis
The final control diagnosis can be used to check the ABS hy‐
draulic pump -V64- and the correct functioning of the hydraulic
circuits (allocation of brake pipes to wheel brakes and function of
valves). This function will also detect interchanged connections
and leaks.
Note
♦
The vehicle must be raised until all wheels are free to turn.
♦
To avoid overloading the control elements they are only acti‐
vated for a period of 60 or 90 seconds. The final control test
will be terminated if the → key is not pressed within this period.
– Remove hydraulic control unit, renew
control unit ⇒ Brake system; Rep. Gr.
45 , then code control unit ⇒ page 39
Do not erase the fault memory of the defec‐
tive control unit. The data in the fault memory
will help to identify the malfunction
♦
The ABS warning lamp -K47- and the red “brake warning”
symbol flash during the final control diagnosis.
♦
After depressing the brake pedal several times the vacuum in
the brake servo will be exhausted. Therefore more pressure
must be applied to the brake pedal in order to attain the same
fluid pressure in the brake system as that attained with vac‐
uum.
♦
When vacuum in brake servo is exhausted it can happen that
the wheels do not lock: start engine and build up vacuum in
brake servo.
Meaning of abbreviations indicated on display
IFL = Inlet valve
OFL = Outlet valve
VBAT = Battery voltage; voltage at valve
0V = 0 Volt; No voltage at valve
Hydr-P = ABS hydraulic pump -V64-
3. ABS/EDL and ABS/EDL/TCS, ITT Mark 20 without ESP 25
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 TT 1999 ➤
Running gear, self-diagnosis - Edition 07.2004
Components of the ABS/EDL system
The hydraulic circuit is a schematic diagram of the ABS/EDL sys‐
tem. The diagram shows only one brake circuit.
1 - Low pressure accumulator
2 - ABS hydraulic pump -V64-
3 - EDL inlet valve (hydraulic)
4 - Noise damping chamber
5 - EDL change-over/separating valve (electrical) with integra‐
ted pressure limiting valve
6 - Front inlet valve
7 - Front outlet valve
8 - Front wheel
9 - Rear inlet valve
10 - Rear outlet valve
11 - Rear wheel
Test condition
• The wheels are locked individually during final control diagno‐
sis. For this test the mechanical and hydraulic components of
the brake system must be working properly. This means that
the master cylinder is able to build up pressure in all four wheel
brake cylinders and there are no leaks in the hydraulic pipes,
hoses and connections.
Note
If one of the wheels does not lock, perform a visual inspection of
the brake fluid reservoir, the master cylinder, the hydraulic unit
and the wheel cylinders.
Procedure
– Connect vehicle diagnostic, testing and information system -
VAS 5051 A- ⇒ page 7 and select vehicle system “03 - Brake
electronics”. When doing this the ignition must be switched on.
Indicated on -VAS 5051 A- :
– Release handbrake.
– Raise vehicle on lifting platform.
– From list -1- select function “03 - Final control diagnosis”.
26 Rep. Gr.01 - Self-diagnosis, electrical checks
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