The traction control switch is a momentary-contact, normally-open switch that can be used to disable the traction control system (TCS). Each time the traction control switch is pressed, the TCS enabled/disabled status changes. When TCS is disabled, the electronic brake control module (EBCM) illuminates the traction off indicator by opening the service traction control signal circuit.

The ignition is ON.

The EBCM detects low voltage on the traction control switch signal for 10 seconds.

The EBCM defaults the traction control system status to Enabled.

The conditions for setting the DTC are no longer present and you use the scan tool Clear DTCS function.

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction.

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

ABS Description and Operation

Electrical Information Reference

Control Module References

Ignition ON, observe the scan tool EBCM Traction Control parameter while pressing the traction control switch. The reading should change between closed/open switch value and scan tool enabled/disabled switch value.

1. Ignition OFF, disconnect the EBCM harness connector at the traction control switch.
2. Ignition ON, verify that a test lamp illuminates between the control circuit terminal C and ground.

⇒	If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal and the control circuit fuse HVD/AIR BRK is open, test the signal circuit terminal for a short to ground.

3. Verify the scan tool traction control system parameter is scan tool open switch value.

⇒	If not the specified value, test the signal circuit terminal D for a short to voltage. If the circuit tests normal, replace the EBCM.

4. Install a 3A fused jumper wire between the signal circuit terminal D and the control circuit terminal C. Verify the scan tool traction control system parameter enabled is scan tool closed switch value.

⇒	If not the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the EBCM.

5. If all circuits test normal, test or replace the traction control switch.

1. Ignition OFF, disconnect the harness connector at the traction control switch.
2. Test for infinite resistance between the signal circuit terminal D and the control circuit terminal C with the switch in the open position.

⇒	If not the specified value, replace the traction control switch.

3. Test for less than 1 ohm between the signal circuit terminal D and the control circuit terminal D with the switch in the closed position.

⇒	If greater than the specified range, replace the traction control switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.