FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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The ABS Lamp Is Constantly On






The ABS lamp is constantly on.

Fault symptoms
The ABS lamp is constantly on.
No DTCs generated.

Conditions
^ Circuit between pin 21 on the ABS control module and pin 10 on the MIU (K20) shorting to ground.
^ Short-circuit contact strip in connector defective.

Diagnostic help
The ABS warning lamp can be activated using the diagnostic tool.
- Select "Activate".
- Select "ABS warning 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 3

YES
go to step 2

2. 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 3

YES
go to step 6

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

Rectify the fault

When repair is complete
Go to step 6

4. Checking The Lead





Check for shorting to B- 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 5

YES
Go to step 6

5. Rectifying The Lead





^ Repair or replace the lead

When repair is complete
Go to step 6

6. Final Check





^ Clear the diagnostic trouble codes in all systems.
^ Carry out a functionality test.

Is the function correct?

NO
Go to step 8

YES
Go to step 7

7. Final Check

The steps taken to rectify the fault were correct.
Diagnosis is complete


8. Final Check

Diagnosis for this fault symptom is complete.
Refer to "Before Changing A Control Module" at General.