ABS Warning Lamp

ABS Warning Lamp

Fault symptoms
The ABS warning lamp is inoperative.

Diagnostic help
The ABS warning lamp can be turned on and off from the ABS control module by means of a diagnostic tool activation command.

Check the wiring harness
Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short-circuits in the leads. Observe the multimeter, test lamp or diagnostic tool during the test

Diagnostic procedure

1. Checking the lamp
- Turn the ignition switch to ON.






- Contact the ABS.






- Activate: ABS lamp (ON).
- The ABS lamp should light up.






Is the function correct?
YES
- Go to step 2.
NO
- Change ABS lamp.
- Go to step 3.

2. Check the lead to the main instrument unit.
- Unplug connector: Main instrument unit's 20-pin connector: (540).






- Connect a test lamp to B+ and pin 10 of MIU K20.






- Turn the ignition switch to ON.






- The ABS lamp in the main instrument unit should come on for 3 seconds and then go out for 0.5 seconds. (If there is no diagnostic trouble code in the ABS).






Is the function correct?
YES
- Change: ABS lamp.
- Go to step 3.
NO
- Repair or replace the lead between pin 10 of the MIU's 20-pin connector and ABS pin 21.
- Go to step 3.

3. Final check
- Clear the diagnostic trouble codes in all systems.






- Perform a functional test.






Is the function correct?
YES
- The steps taken to rectify the fault were correct.
NO
- See Fault diagnosis, general, "Before changing a control module." Before Changing A Control Module