engine AUDI A8 1995 D2 / 1.G AHA Engine On Board Diagnostic Owner's Guide

Fuse for Engine Control Module (ECM) OK
Closed Throttle Position (CTP) switch -F60-
OK
Fuel pump relay OK
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01-53

Test sequence

- Connect VAG1551/VAG1552 scan tool and
insert "Engine Electronics" address word 01
(ignition on) page 01
-8 .
Rapid data transfer
HELP
Select function XX

Indicated on display
- Press buttons -0- and -3- to select "Output Diagnostic Test Mode"
function 03.
Rapid data transfer
Q
03 - Output Dia
gnostic Test Mode

Indicated on display
Fuel injectors:
- Press -Q- button to confirm input.
Output Diagnostic Test Mode Cylinder 1 Fuel In
jector-N30

Indicated on display
Note:
The fuel pump relay must be activated, the fuel pump must run, and you
must clearly hear the flow of fuel in the fuel pressure regulator. If the fuel
pump does not run, check fuel pump relay and connections page 24
-
95
.
- Operate throttle valve at throttle body.
As soon as the Closed Throttle Position (CTP) switch opens, cylinder 1
fuel injector must be actuated (click) 5 times.
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01-55

EVAP canister purge regulator valve -N80-:

-
Press button.Output Diagnostic Test Mode EVAP Canister Pur
ge Re
gulator Valve-N80

Indicated on display
The valve will click until pressing the button to advance the program
sequence.
If the valve is not actuated (does not click):
Secondary Air Injection (AIR) solenoid valve -N112-: - Check EVAP canister purge regulator valve page 24
-116
.
-
Press button.
Output Diagnostic Test Mode Secondar
y Air In
jection Valve-N112

Indicated on display
The valve will click until pressing the button to advance the program
sequence.
If the valve is not actuated (does not click): - Check secondary air injection solenoid valve -N112- Repair Manual,
2.8 Liter V6 5V Engine Mechanical, Repair Group 26.
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01-56

Secondary Air Injection (AIR) pump relay -
J299-:

-
Press button.Output Diagnostic Test Mode Secondary Air Injection Relay-J299

Indicated on display
The relay will be actuated and turn on the secondary AIR pump motor
until pressing the button to advance the program sequence.
If the relay is not actuated (does not click) or the motor does not run:
Intake manifold tuning valve -N156- (change-over valve): - Check secondary air injection pump relay -J299- Repair Manual, 2.8
Liter V6 5V Engine Mechanical, Repair Group 26. -
Press button.
Output Diagnostic Test Mode Intake Manifold Changeover Valve-N156

Indicated on display
The valve will click until pressing the button to advance the program
sequence.
If the valve is not actuated (does not click): - Check intake manifold tuning valve -N156- page 24
-116
.
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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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01-59

Notes:
After selecting "Basic Setting" function 04, the
ECM takes the following actions:

EVAP canister purge regulator valve is
closed
A/C compressor is switched of
f

Requirements

Vehicle stationary, engine running at idle
Accelerator pedal not depressed
Selector lever in "P" or "N" position
No malfunctions stored in DTC memory
Engine coolant temperature at least 80 C
(176 F)

All electrical consumers switched off (coolant
fan must not run during test)

A/C switched off (press "-" button on A/C
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01-60

Test sequence

- Connect VAG1551/VAG1552 Scan Tool (ST)
and press buttons -0- and -1- to insert "Engine
Electronics" address word 01 (engine running at
idle) page 01
-8 .
Rapid data transfer
HELP
Select function XX

Indicated on display
Note:
By pressing the HELP button an overview of possible functions will be
printed out. - Operate scan tool while observing messages on display:
- Press buttons -0- and -4 to select "Basic Setting" function 04, and
press -Q- button to confirm input.
System in Basic Setting
Q
Input display group number XXX

Indicated on display
Note:
Display group number 0 (000) is used as an example to demonstrate the
procedure.
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01-62

Display group 000 (display in decimal values)

Engine running at idle; ECM in "Basic Setting" function 04
Display fields
Specified
value Corresponds to
1
2
3 4
5 6
7 8
9 10
Idle learn value (additive) for O2S control, bank 2 115-141 -0.65 to +0.65
ms





Idle learn value (additive) for O2S control, bank 1
115-141


-0.65 to +0.65
ms



O2S control bank 2 (if outside of tolerance, conduct test
drive) 77-179 -10 to +10 %




O2S control bank 1 (if outside of tolerance, conduct test
drive)
77-179
-10 to +10 %


Learn value-idle air flow 118-138 -5.0 to +5.0 kg/h



Idle air control value
118-138
-5.0 to +5.0 kg/h

Throttle angle 0-12
0-5


Engine speed (with electrical consumers switched off)
All-wheel drive vehicles
Front-wheel drive vehicles

62-74
74-86

620-740 RPM
740-860 RPM

Engine load (with electrical consumers switched off) 20-50 1.0-2.5 ms
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Engine coolant temperature (necessary for "Basic Setting")
170-204
80-105 C
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01-63
Display group 000-evaluation Display field
1
Possible malfunction cause
Corrective action
greater than
204
Engine coolant temperature (ECT) sensor -
G62- - Check ECT sensor page 24
-75
less than 170

Engine coolant temperature (ECT) sensor -
G62- - Check ECT sensor page 24
-75


Coolant thermostat faulty (open)
Repair Manual, 2.8 Liter V6 5V Engine Mechanical,
Repair Group 19 - Check thermostat
Display field
2
Possible malfunction cause
Corrective action
greater than
50
Electrical consumers switched on- Switch off electrical consumers

Oxygen Sensor (O2S) control at limit- Check HO2S and O2S control before TWC page 24
-
22

- Check HO2S aging, bank 1, sensor 1 (before TWC)
page 24
-60

- Check HO2S aging, bank 2, sensor 1 (before TWC)
page 24
-63

less than 20

Intake air leaks ("false air")- Check intake air system for leaks page 24
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