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

01-64

Display field 3
Possible malfunction cause
Corrective action
less than 62
(all-wheel drive)
or
less than 74
(front-wheel drive)
Drive range selected
Throttle valve control module faulty- Move selector lever to "P" or "N" position
- Check idle speed page 24
-16
- Check throttle valve control module page 24
-128

less than 74
(front-wheel drive)
Supply voltage (terminal 15) to terminal 10
of Engine Control Module (ECM) missing - Check supply voltage (terminal 15) to terminal
10 of ECM using applicable wiring diagram
greater than 74
(all-wheel drive)
or
greater less than 86
(front-wheel drive) Closed Throttle Position (CTP) switch open
Throttle valve control module faulty
Intake air leaks ("false air")- Check idle speed page 24
-16
- Check throttle valve control module page 24
-128

- Check intake air system for leaks page 24
-
126

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01-65

Display field 4
Possible malfunction cause
Corrective action
less than 0 (Not possible) ---
greater than 12

Adaptation of throttle valve control module to
ECM not complete - Check adaptation of throttle valve control
module page 24
-150

greater than 12

Throttle Position (TP) sensor in throttle valve
control module faulty - Check throttle valve control module page 24
-
128

greater than 12

Throttle valve mechanism sticking
Contamination in intake air ducting near throttle
valve - Check by visual inspection and repair as
necessary
greater than 12
Accelerator pedal cable adjustment
Repair Manual, Fuel Supply System, Repair
Group 20
- Adjust accelerator pedal cable
Display fields 5
+ 6
Possible malfunction cause
Corrective action
less than 118

Intake air leaks ("false air") after throttle valve- Check intake air system for leaks page 24
-
126

greater than
138
Increased engine load- Switch off electrical consumers

Throttle valve mechanism sticking
Contamination in intake air ducting near throttle
valve - Check by visual inspection and repair as
necessary
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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

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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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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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