GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

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

DTC Descriptor

DTC C0110 04: Pump Motor Circuit Open

DTC C0110 61: Pump Motor Circuit Actuator Stuck

Diagnostic Fault Information

Circuit

Short to Ground

Open or High Resistance

Short to Voltage

Signal Performance

Pump Motor Ground

--

C0110 04

--

--

Pump Motor

--

--

--

C0110 61

Circuit/System Description

The electronic brake control module (EBCM) supplies ground to activate the antilock brake system (ABS) pump motor. An internal system relay in the EBCM supplies battery positive voltage to the pump motor when the ignition is turned ON. The EBCM monitors pump motor feedback voltage after activation to detect a stalled or binding pump motor.

Conditions for Running the DTC

C0110 04

    • System and ignition voltage is above 10.5 volts.
    • The system enable relay is ON.
    • The pump motor has been commanded OFF for 2.5 seconds.

C0110 61

    • DTC C0110 04 is not set.
    • The system enable relay is ON.
    • The pump motor has been commanded ON, OFF and ON again.

Conditions for Setting the DTC

C0110 04

The EBCM detects an open in the pump motor circuit when the voltage across the pump motor is between 10 and 90 percent of ignition voltage.

C0110 61

The pump motor is constantly being commanded on and off to when a certain motor RPM is desired. The feedback voltage is monitored and if the RPM is detected below the specified value for 4 consecutive attempts a binding or stalled pump motor fault is set.

Action Taken When the DTC Sets

    • The EBCM disables the ABS/traction control system (TCS)/vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
    • The dynamic rear proportion (DRP) is degraded.
    • The ABS indicator turns illuminates.
    • The stability control indicator illuminates.
    • The traction control indicator illuminates.

Conditions for Clearing the DTC

    • The condition for the DTC is no longer present.
    • The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids

The pump motor is integral to the brake pressure modulator valve (BPMV). The pump motor is not serviceable.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

ABS Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the EBCM.
  2. Test for less than 1 ohm between the ground circuit terminal E and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminals A and B and ground.
  5. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test or replace the BPMV.
  6. Ignition OFF, remove the EBCM from the BPMV.
  7. Inspect the EBCM to BPMV connector for no damage, corrosion, or presence of brake fluid.
  8. If connector corrosion or damage is evident, replace BPMV and/or EBCM as necessary.
    If brake fluid is present, replace both BPMV and EBCM.
  9. If all circuits test normal, replace the BPMV.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Brake Pressure Modulator Valve Replacement
    •  Control Module References for EBCM replacement, setup, and programming