Traction Control Indicator Always On

Traction Control Indicator Always On

Circuit Description

The electronic brake control module (EBCM) controls the operation of the traction control system (TCS) lamp. Battery voltage is supplied to the instrument panel (I/P) cluster terminal B14 when the ignition switch is turned ON. EBCM terminals 9 and 25 are hot at all times.

When the EBCM commands the TCS lamp OFF, the EBCM will ground the TCS lamp control circuit. This causes the lamp driver module (LDM) to open the path to ground for the bulb.

When the ignition switch is turned to the ON position, the EBCM turns ON the TCS lamp for 3 seconds for a bulb check.

Whenever a malfunction is detected within the general brake system or de-coupled dynamic rear proportioning (DDRP), the EBCM turns ON the TCS lamp, notifying the driver the brake system or DDRP needs to be serviced.

Diagnostic Aids

The typical cause of the TCS lamp ON with no DTCs set is mainly EBCM wiring harness short to battery.