TCS Off Warning Lamp Constantly On

Fault symptoms
TCS OFF 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 TCS OFF warning lamp can be activated with the diagnostic tool.
- Select "Activate"
- Select "TCS OFF Lamp"

Diagnostic procedure
1. Checking The Wiring Harness





Unplug the connector:
Main instrument unit 20-pin connector (540)





Turn the ignition switch to the ON position.





Connect test lamp 86 11 857 between B+ and pin 13 on the female connector.

^ Jiggle the leads and in-line connector at several places and in different directions to reveal intermittent brakes and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.

The Test lamp should not light





Contact TC/ABS control module.

Activate TCS lamp ON

^ Jiggle the leads and in-line connector at several places and in different directions to reveal intermittent brakes and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.

The test lamp should light

Is the function Correct?

NO
Go To Step 2

YES
Go To Step 3

2. Rectifying The Lead





Rectify the lead between pin 28 on the TC/ABS control module and pin 13 on the MIU (K20).

When the repair is complete
Go To Step 4

3. Checking The Wire Harness

^ Change the TCS lamp in the main instrument unit.

When repair is complete:
Go To Step 4

4. Final Check





^ Clear the diagnostic trouble codes in all systems

^ Carry out a functionality test.

Is the function correct?

NO
Go To Step 5

YES
Go To Step 6

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

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