When the body control module (BCM) sees the traction control switch input grounded through the momentary traction control switch, it sends a serial data message to the electronic brake control module (EBCM) that tells the EBCM that the traction control switch has been pressed. The EBCM then disables traction control and sends a serial data message to the instrument cluster to turn ON the Traction Off indicator on the instrument panel. Each time the ignition is cycled from OFF to ON, the traction control system is enabled.

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Antilock Brake System Connector End Views

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

1. With the scan tool, select instrument panel special functions Lamp Test. Command the instrument panel lamps ON. Verify traction off lamp turns ON.

⇒	If the traction off lamp does not turn ON, replace the instrument panel cluster (IPC).

2. Ignition OFF, disconnect traction control switch connector. Ignition ON, measure for 10-13 volts between traction control switch signal circuit and ground.

⇒	If under 10 volts test for short to ground, open, high resistance or replace BCM.

3. Ignition ON, measure for 10-13 volts between traction control switch signal circuit and traction control switch ground at switch connector.

⇒	If under 10 volts test for open or high resistance in traction control switch ground circuit.

4. Replace traction control switch.

Disconnect traction control switch connector. Connect a DMM between terminals of switch. Press switch and verify there is continuity.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM, IPC, and BCM replacement, setup, and programming