lock AUDI A8 1995 D2 / 1.G AHA Engine On Board Diagnostic Workshop Manual

01-6
Functions under "Engine Electronics" address word 01: Function 01: Check Control Module
Version Ignition switched on -or- Engine running at idle
Function 02: Check DTC Memory Engine running at idle, otherwise crank engine with starter motor for at least 5 sec.,
then do not switch ignition off
Function 03: Output Diagnostic
Test Mode Ignition switched on
Function 04: Basic Setting Engine running at idle
Function 07: Code Control Module Ignition switched on
Function 08: Read Measuring
Value Block Ignition switched on -or- Engine running at idle -or- Driving
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01-7
Modes under address word 33: Mode 1: Transfer diagnostic data Ignition switched on -or- Engine running at idle
Mode 2: Transfer operating conditions Ignition switched on -or- Engine running at idle
Mode 3: Check DTC memory Ignition switched on -or- Engine running at idle
Mode 4: Erase diagnosis information Ignition switched on -or- Engine running at idle
Mode 5: Output of HO2S signals Ignition switched on -or- Engine running at idle
Mode 6: Transfer measuring values Ignition switched on -or- Engine running at idle
Mode 7: Check DTC memory Ignition switched on -or- Engine running at idle Under Address word 33, Modes 1-7 can be addressed.
Under Mode 1, individual measuring values can be displayed. Mode 1 is not recommended for use in an Audi Service
department, because these values can be displayed much more precisely using address word 01 and "Basic Setting"
function 04 or "Read Measuring Value Block" function 08.
Mode 2 shows the operating conditions under which the stored malfunctions were recognized.
With Mode 3, DTC memory is checked-with Mode 4, DTC memory is erased.
Mode 5 shows the statistical value of the oxygen sensors as mandated by law. As these values have no direct bearing on
oxygen sensor diagnosis, Mode 5 is of no particular value in an Audi Service department.
Under Mode 6, values can be checked for components and systems that are not continuously monitored.
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01-40

Diagnostic Trouble
Code (DTC)
Malfunction
text
MIL
Corrective action
SAE
VAG



P1250 17658 Fuel Level
Too Low Off
Repair Manual, Electrical Equipment, Repair Group 01 (instrument cluster diagnostics, Read Measuring Value Block)
- Fuel volume less than 2 gallons; add fuel
- Check "fuel level low" signal page 24
-176
- Check fuel level sensor signal and fuel gauge
Note on misfire malfunctions:
For malfunctions that may be caused by low fuel volume (i.e. combustion misfire) a low-fuel malfunction (DTC "P1250") is also
stored when there is less than 2 gallons of fuel remaining in the tank.
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01-58

Basic Setting (scan tool function 04)


Notes:

The specified values for the "Basic Setting" and
"Read Measuring Value Block" functions are
described in the respective component test
descriptions.
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.
No learning will take place if a malfunction
affecting engine regulation is stored in DTC
memory (this does not include sporadic
malfunctions).
Basic settings are established with the engine
running.
In "Basic Setting" display groups 60 or 98, with
the engine stopped and the ignition switched
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on, adaptation of the throttle valve control
module -J338- takes place. Adaptation of
throttle valve control module -J338- (with "Basic
Setting" function 04 and display group 60)
page 24
-150
.

In "Basic Setting" display groups 88 or 99,
oxygen sensor control is switched off. This
makes it possible to check for malfunctions that
may be caused by oxygen sensor control being
switched on or off. In the selected display
group, press buttons -4- and -8- to switch back
and forth between "Read Measuring Value
Block" function 08 and "Basic Setting" function
04.
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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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