TCS Cannot Be Disengaged With Switch

Fault symptoms
TCS cannot be disengaged with switch.

When the ignition is switched ON, the TCS OFF warning lamp comes on for 10 seconds and then goes out.

No DTCs are set.

Conditions
Break/short circuit in control module input from the TCS OFF switch.

Diagnostic help
A reading of the ON/OFF status of the switch can be obtained with the diagnostic tool.
- Select: "Read values"
- Select "Switch, TCS OFF"

With the switch depressed the reading obtained should be ON.

If the lead is grounded for more than 10 seconds, the TC/ABS control module will engage the TCS function and after that it will not be possible to disengage the function without first switching off the ignition and then switching it on again.

Diagnostic procedure
1. Checking The Switch's Grounding





Unplug the connector:
TCS switch 449





Connect test lamp 86 11 857 between B+ and pin 7 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 light

Is the function Correct?

NO
Go To Step 2

YES
Go To Step 3

2. Rectifying The Lead





Rectify the lead between the female connector to the switch, pin 7 and grounding point G41S.

When repair is complete:
Go To Step 6

3. Checking Control Module Input





Contact TC/ABS control module

Read Value:
TCS Switch TC/ABS control module

^ The diagnostic tool should display: OFF.

Connect a jumper lead between pin 2 and pin 5 of the female connector.

Read Value:
TCS Switch TC/ABS control module

^ The diagnostic tool should display: ON.

Is the function Correct?

NO
Go To Step 4

YES
Go To Step 5

4. Rectifying The Lead





Rectify the lead between the female connector to the switch, pin 5 and control module female connector pin 31.

When repair is complete:
Go To Step 6

5. Changing Components





Change the TCS switch
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 7

YES
Go To Step 8

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

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