wheel AUDI A4 1999 B5 / 1.G APB Engine Additional Signals Checking Workshop Manual

24-183

- Take vehicle for a test drive and check whether
vehicle speed appears in display field 3.

- If vehicle speed does not appear, raise the
vehicle (preferably using a lift) until front left
wheel is clear of the ground.

Electrical Wiring Diagrams, Troubleshooting & Component Locations - Connect VAG1598/31 test box to wiring harness for engine control
module. Do not connect to the engine control module itself Page 24
-
20
.
- Connect diode test lamp between socket 3 (B+) and socket 54 (vehicle
speed signal).
- Switch ignition on and turn front left wheel by hand.
The diode test lamp should flash (very brief flashes).
- If diode test lamp does not flash, check for open circuit or short to B+
or Ground (GND) in wiring between instrument panel and terminal 54
on engine control module connector.
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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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