ABS Warning Lamp Constantly On

Fault symptoms
ABS warning lamp constantly on.
No DTCs are set.

Conditions
Bus communication must be functioning. See System overview, refer to Description and Operation.

Diagnostic help
The ABS warning lamp can be activated with the diagnostic tool.
- Select "Activate"
- Select "ABS lamp"

Diagnostic procedure
1, Checking The Short-Circuit Contact Strip





^ Break the contact strip.
The ABS warning light should now be extinguished.

Is the function correct?

NO
Go To Step 2

YES
Go To Step 5

2. Checking the lead





^ Check for shorting to B- (ground) in the lead between pin 21 of the control module and pin 10 of the MIU (K20).

Is the function correct?

NO
Go To Step 3

YES
Go To Step 4

3. Rectifying The Lead





Repair or replace the lead

When repair is complete:
Go to step 7

4. Checking the lead

Continue with fault diagnosis of the MIU
Refer to Instrument Panel, Gauges and Warning Indicators.

5. Checking The Operation Of The Short-Circuit Contact-Strip





^ Check that the breakpin in the short-circuiting contact strip is in proper working order.

Is the function correct?

NO
Go To Step 6

YES
Go To Step 7

6. Checking The Operation Of The Short-Circuit Contact-Strip

^ Rectify the fault.

When repair is complete:
Go To Step 7

7. Final Check





^ Clear the diagnostic trouble codes in all systems

^ Cary out a functionality test.

Is the function correct?

NO
Go To Step 8

YES
Go To Step 9

8. Final Check
See Before changing a control module, refer to General Fault Diagnosis.
^ Diagnosis for this fault code is complete.

9. Final Check
The steps taken to correct the fault were correct.
^ Diagnosis is complete.