display AUDI A6 1997 C5 / 2.G AHA Engine On Board Diagnostic Owner's Manual

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.
Pa
ge 82 of 97 On Board Dia
gnostic
(OBD
)
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.01.1

01-61
To change to another display group:

Display
group
VAG1551
VAG1552
higher Press -3-
button Press
button
lower Press -1-
button Press
button skip Press -C-
button Press -C-
button

- Press -0- button three times to input display
group number 0 (000), and press -Q- button to
confirm input. System in Basic Setting 1 2 3 4 5 6 7 8 9 10

Indicated on display
Notes:
In display group 0 the measuring values are displayed in decimal
form. The display can be printed out by pressing the PRINT button.
-
If specified values were attained in all display fields, press button to
advance through program sequence.
Rapid data transfer
HELP
Select function XX

Indicated on display
-
Press buttons -0- and -6- to select "End Output" function 06, and press
Pa
ge 83 of 97 On Board Dia
gnostic
(OBD
)
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.01.1

-Q- button to confirm input.
- If one of the specified values is not attained page 01
-63
evaluation
of display group 000.
- Continue by using procedures in "Corrective action" column.
Pa
ge 84 of 97 On Board Dia
gnostic
(OBD
)
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.01.1

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
Pa
ge 85 of 97 On Board Dia
gnostic
(OBD
)
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.01.1

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
-126Pa
ge 87 of 97 On Board Dia
gnostic
(OBD
)
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.01.1

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

Pa
ge 89 of 97 On Board Dia
gnostic
(OBD
)
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.01.1

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
Pa
ge 90 of 97 On Board Dia
gnostic
(OBD
)
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.01.1

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
ge 91 of 97 On Board Dia
gnostic
(OBD
)
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.01.1

Display field 9 + 10
Possible malfunction cause
Corrective action
less than 115 or greater
than 141
Display group 32, evaluating page 24
-27
Pa
ge 92 of 97 On Board Dia
gnostic
(OBD
)
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.01.1

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)
Pa
ge 95 of 97 On Board Dia
gnostic
(OBD
)
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.01.1