AUDI A8 1999 D2 / 1.G AHA Engine On Board Diagnostic Owners Manual

01-66

Display fields 7 + 8
Possible malfunction cause
Corrective action
less than 77

Mixture too rich-oxygen sensor control
adjusts toward too lean
Oxygen sensor control at limit
Too much fuel vapor from EVAP canister
Fuel pressure regulator faulty, or hose
disconnected - Check HO2S and O2S control before TWC
page 24
-22

- Check fuel pressure regulator page 24
-111
greater than 179

Mixture too lean-oxygen sensor control
adjusts toward too rich
Intake air leaks ("false air")
Fuel injector(s) faulty
Oxygen sensor control at limit- Check HO2S and O2S control before TWC
page 24
-22

- Check intake air system for leaks page 24
-
126

- Check fuel injector(s) page 24
-102


Secondary air system
Output Diagnostic Test Mode (DTM), page 01
-
51
and
Repair Manual, 2.8 Liter V6 5V Engine
Mechanical, Repair Group 26 - Check secondary air system
128

Too little fuel
Oxygen sensor control blocked- Check fuel level in tank
- Check HO2S and O2S control before TWC
page 24
-22

Pa
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Display field 9 + 10
Possible malfunction cause
Corrective action
less than 115 or greater
than 141
Display group 32, evaluating page 24
-27
Pa
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01-67

VAG1598/22 test box, connecting


Notes:

Switch the ignition off and wait at least 10
seconds before disconnecting the Engine
Control Module (ECM) harness connector.
Disconnecting the battery or the Engine Control
Module (ECM) harness connector will erase all
learned values and the readiness code.
Diagnostic Trouble Code (DTC) memory,
however, will not be erased. After reconnecting
the battery and/or the ECM, the engine may idle
unevenly and there may be some temporary
loss of driveablity. If so, let the engine run at
idle for a few minutes until the learning process
has been completed.

- Switch ignition off.

- Disconnect ECM.

- Connect VAG1598/22 adapter cable to ECM
harness connector.

- Generate readiness code page 01
-73
.

Note:
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If the DTC memory has been erased or the ECM
was disconnected from its power supply, a new
readiness code must be generated page 01
-
73
.
Pa
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01-68

Engine Control Module (ECM), replacing


Notes:

Switch the ignition off and wait at least 10
seconds before disconnecting the Engine
Control Module (ECM) harness connector.
Disconnecting the battery or the Engine Control
Module (ECM) harness connector will erase all
learned values and the readiness code. After
reconnecting the battery and/or the ECM, the
engine may idle unevenly and there may be
some temporary loss of driveablity. If so, let the
engine run at idle for a few minutes until the
learning process has been completed page 01
-58
.

After installation of a new ECM, set ECM
coding and carry out adaptation of the throttle
valve control module -J338-.
If the ECM has been replaced, carry out the
following steps in the sequence listed.

- Connect VAG1551/VAG1552 Scan Tool (ST)
and press buttons -0- and -1- to insert "Engine
Electronics" address word 01 (with ignition
switched on) page 01
-8 .
Indicated on display (ECM identification and coding)
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4D0907551A 2.8l V6/5V MOTR HS D01 Codin
g 06051
WSC 00000

- Print out ECM coding and compare with code table page 01
-14
.
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01-69

-
Press button.Rapid data transfer HELPSelect function XX

Indicated on display
Note:
If the DTC memory has been erased or the ECM was disconnected from
its power supply, a new readiness code must be generated page 01
-
73
. - Switch ignition off.
- Replace faulty ECM.
- Check ECM coding page 01
-12
.
- Carry out adaptation of throttle valve control module -J388- to ECM
page 24
-150
.
- Generate readiness code page 01
-73
.
Pa
ge 97 of 97 On Board Dia
gnostic
(OBD
)
11/23/2002 htt
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yp
e=re
pair&id=AUDI.B5.FU03.01.1