ABS Indicator Always On

ABS Indicator Always On

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

Circuit/System Description

The electronic brake control module (EBCM) turns ON the Antilock Brake System (ABS) indicator by opening the ABS indicator control circuit. The ABS indicator is connected to the GAUGE fuse. This circuit has power when the ignition switch is in the ON or START positions. When the ignition switch is turned to the ON position, the EBCM turns ON the ABS indicator for 3 seconds for a bulb check. If the EBCM detects a malfunction, the ABS indicator will stay ON to warn the driver that the ABS is disabled and needs service.

Reference Information
Schematic Reference

Antilock Brake System Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

ABS Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

1. Verify DTC U0073, U0123, U0124, or U0126 are not set.

• If DTC U0073, U0123, U0124, or U0126 is set, refer to appropriate DTC.

2. Verify EBCM connector is secure.

• If EBCM connector is not secure, repair EBCM connection

3. Verify battery voltage is 11-14V.

• If battery voltage is not as specified, test charging system, and/or replace battery if necessary.

Circuit/System Testing

1. Ignition OFF, disconnect the EBCM connector.
2. Ignition ON, check for 11-14V between the B+ circuit and ground.

• If the voltage is not as specified, test the B+ circuit for a short to ground or an open/high resistance.

3. Test for less than 1 ohm between the ground circuit and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the BPMV/EBCM.

4. Using a scan tool, command the IPC display test ON and OFF. The ABS warning indicator should turn ON and OFF.

• If IPC does not perform as specified, replace the IPC.

• If IPC performs as specified, replace the BPMV/EBCM.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Brake Pressure Modulator Valve Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for EBCM replacement, setup, and programming