1995 AUDI A6 ATW Engine On Board Diagnostic Workshop Manual

01-8

B- Exhaust MIL remains constantly lit

- Check DTC memory of Engine Control Module
(ECM) Page 01
-16
.
If no DTCs are stored:

- Connect VAG1598/31 test box at wiring harness
to Engine Control Module (ECM), do not connect
ECM Page 24
-19
.

- Remove instrument cluster:

Repair Manual, Electrical Equipment, Repair
Group 90; Instrument cluster, removing and installing


- Check following wire connection for short circuit
to Ground (GND):

Test box
VAG1598/31
Socket
Instrument cluster

Terminal
47 Electrical Wiring Diagrams,
Troubleshooting & Component
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Locations

- Repair short circuit if necessary.
If wire connection is OK:

- Replace Engine Control Module (ECM) Page
24
-23

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01-9

Safety precautions

If special testing equipment is required during
road test, note the following:

WARNING!

Test equipment must always be secured to
the rear seat and operated from there by a
second person.
If test and measuring equipment is operated
from the passenger seat, the person seated
there could be injured in the event of an
accident involving deployment of the
passenger-side airbag.
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01-10

VAS5051 tester or VAG1551 scan tool,
connecting and selecting functions


Test requirements:

Fuses for engine electronics OK

Electrical Wiring Diagrams, Troubleshooting &
Component Locations

Fuel Pump (FP) relay OK; checking Page 24
-53
.

Battery voltage at least 12.7 V
Ground (GND) connections at engine and
transmission OK

Procedure

Note:
Data Link Connector (DLC) is located in front left knee bolster. - Connect VAS5051 tester to vehicle with VAS5051/1 diagnostic wire.
Alternately, VAG1551 Scan Tool (ST) can also be attached using
VAG1551/3A adapter.
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01-11

WARNING!

Observe safety precautions Page 01
-9 .

Note:
The following description only explains
implementation of On Board Diagnostic using
VAG1551 Scan tool. When using the VAS5051
tester, observe instructions in the tester's user
manual. VAG - On Board Diagnostic (OBD)
HELP
1- Rapid data transfer1
)
2- Blink code output1
)

Indicated on display 1) Operating modes 1 and 2 are displayed alternately
Note:
If nothing appears in display:
- Perform troubleshooting procedure after "troubleshooting procedure leak
test":
Electrical Wiring Diagrams, Troubleshooting & Component Locations
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01-12
Depending on desired function Table
"Selectable functions", Page 01
-15
:

- Switch ignition on.
or

- Start engine.

- Press -Print- button to turn on Scan Tool (ST)
printer. Indicator lamp in button must light up.

- Press button 1 to select "Rapid data transfer"
operating mode 1. Rapid data transfer
HELP
Enter address word XX

When indicated on display
Note:
The address word 00 initiates the automatic test sequence, i.e. it results in
a DTC check on all OBD capable systems in the vehicle via rapid data
transfer.
- Press buttons -0- and -1- to select "engine electronics" and press -Q-
button to confirm input.
4B0906018Q
1.8 L R4/5VT
G 0008
Codin
g 07551
WSC 12345

VAG1551 Scan Tool (ST) display indicates control module identification,
e.g.
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01-13

Note:
Control module identification can be printed by
pressing the PRINT key on the VAG1551 scan
tool.

Control module identification (example)

4B0906018Q part number; allocation
Parts Catalog 1.8LEngine displacement R4/5VTInline engine, 4 cylinders / 5
valve turbo "G" i.e. no
indication Vehicle with or without cruise
control system 0008Data version (software
version) of control module Coding 07551 Control module coding WSC 12345 Factory identification of
VAG1551, with which the last
coding was performed

-
Press button.
Rapid data transfer
HELP

Indicated on display (function selection)
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Select function XX
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