2000 AUDI A4 engine

24-190
If LED comes on:

Check activation

- Connect VAG1598/31 test box to wiring harness
for engine control module. Do not connect to the
engine control module itself Page 24
-20
.
Test the following wiring connections for open
circuits and short to B+ or Ground (GND):

Harness
connector
terminal
VAG1598/31 test box,
socket
2 56
4 55

- Repair any open/short circuit as necessary.
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24-191

Clutch Vacuum Vent Valve Switch -F36,
checking


Note:
This signal is used to avoid RPM over-oscillation
and load change impacts when changing gears
and is also used for the cruise control system.

Test sequence

- Connect vehicle diagnostic, testing and
information system VAS 5051 or VAG1551 scan
tool and select engine electronics control
module by entering address word "01" Page
01
-9 .
When doing this the ignition must be switched
on. Rapid data transfer
HELP
Select function XX

Indicated on display
- Press buttons -0- and -8- to select function "Read Measuring Value
Block" and confirm entry with -Q- button.
Read Measurin
g Value Block
Input displa
y group number XXX

Indicated on display
- Press buttons -0-, -6- and -6- to select "display group number 066" and
confirm entry with -Q- button.
Read Measuring Value Block 66

Indicated on display
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24-192


Display fields

1 2 3 4
Display Group 066: Signals to engine control module
Display xxx km/h
X X X X xxx km/h 0 0 0 0
Indicates Actual speed
Switch positions Specified speed Switch positions
Work
range
X0XX
X1XX

Specified value
X0XX
Clutch pedal not depressed

X1XX
Clutch pedal depressed
Note
Value:
X = insignificant
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24-195
If LED comes on:

Check activation

- Connect VAG1598/31 test box to wiring harness
for engine control module. Do not connect to the
engine control module itself Page 24
-20
.
Test the following wiring connections for open
circuits and short to B+ or Ground (GND):

Harness
connector
terminal
VAG1598/31 test box,
socket
1 39

- Repair any open/short circuit as necessary.
Pa
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g
11/22/2002 htt
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yp
e=re
pair&id=AUDI.B5.FU04.24.6

24-196

Crash signal, checking

The Engine Control Module (ECM) receives the
crash signal ("Crash shut-down activated") from
the airbag control module.
If the airbag control module sends the crash
signal to the ECM (if an accident occurred or if a
output Diagnostic Test Mode (DTM) was carried
out), the ECM shuts off the fuel pump, that
means the engine stalls, however, afterwards the
engine can be started again (e.g. when removing
the vehicle from the accident area)
The ECM cannot switch off the fuel pump during
an accident if the malfunction "Crash Signal from
Airbag Control Unit/Range Performance" from
the airbag control module is sent to ECM. The
engine control module cannot recognize the
crash signal from the airbag control module; e.g.:
if the wiring between the ECM and the airbag
control module is faulty.

- Connect VAG1598/31 test box to wiring harness
for engine control module. Do not connect to the
engine control module itself Page 24
-20
.
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24-198

Signal for rough road recognition from
ABS/EDL control module, checking


Note:

The ABS/EDL control module generates the
rough road signal if it recognizes wheel spin on
a wheel. The Engine Control Module (ECM)
switches off the misfire recognition once the
rough road signal is recognized by the ECM.
The rough road signal should only be checked if
the malfunction (P1606) 18014 "Rough Road
Spec Engine Torque ABS-ECU/Electrical
Malfunction" is stored in the DTC memory. It is
possible that the malfunction "Misfiring" is also
stored in DTC memory, however this is then a
sequence error and should be ignored.
The wiring and the rough road signal is
monitored by the ECM.
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24-199

Test conditions

Control module coding OK Page 01
-93
.

Test sequence

- Connect VAG1598/31 test box to wiring harness
for engine control module. Do not connect to the
engine control module itself Page 24
-20
.

- Check wire from test box socket 74 to ABS
Control Module according to wiring diagram for
short circuit or open circuit.

Electrical Wiring Diagrams, Troubleshooting &
Component Locations
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24-200
If no malfunction is detected:

- Replace ABS control module.
If, after the ABS control module has been
replaced the malfunction appears again:

- Replace Engine Control Module (ECM) Page
24
-24
.
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