The electronic brake control module (EBCM) receives a signal from the trailer Antilock Brake System (ABS) module over the Ignition 1 voltage circuit. The EBCM applies ground to the trailer ABS indicator control circuit in order to turn ON the TRAILER ABS indicator.

Disconnecting the trailer from the tractor checks if that was the cause of the Trailer ABS indicator illuminating. If upon disconnecting the trailer the Trailer ABS indicator stops illuminating check the trailer manufacturer. If no trailer was hooked to the tractor please proceed to Circuit/System Testing.

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

ABS Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for EBCM

1. Ignition OFF for 5 seconds.
2. Ignition ON, observe the Driver Information Center (DIC) Trailer ABS Indicator. The Indicator should illuminate then turn OFF.

1. Ignition OFF, disconnect the electronic brake control module (EBCM) harness at the driver information center (DIC). The Trailer ABS indicator should turn OFF.

⇒	If the indicator turns OFF, test or replace the EBCM.

2. Ignition OFF, disconnect the telltale circuit board circuit connector containing the trailer ABS indicator control circuit within the driver information center (DIC).

⇒	If the indicator does not turn OFF, test the ABS indicator control circuit for a short to ground and open/high resistance. If the circuit tests normal, replace the telltale circuit board.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. Turn OFF the ignition for 5 seconds.
2. Turn ON the ignition, while observing the Trailer ABS Warning Light Indicator.
3. The ABS Warning Light Indicator should light for 2 seconds then turn off.

⇒	If the ABS indicator does not light, recheck the circuit/system testing.