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 Descriptors

DTC C0110 04: Pump Motor Circuit Open Circuit

DTC C0110 61: Pump Motor Circuit Actuator Stuck

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

B+

C0110 61

C0110 61

C0110 04

C0110 04, C0110 61

Ground

--

C0110 61

--

--

Circuit/System Description

The electronic brake control module (EBCM) supplies ground to activate the 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

    • Ignition ON.
    • The system enable relay is ON.

Conditions for Setting the DTC

C0110 04

The EBCM detects an open in the pump motor circuit when the feedback voltage remains greater than 0.75 volt for more than 50 msec.

C0110 61

The pump motor continues to rotate briefly after activation creating a feedback voltage. The EBCM sets the code if the measured feedback voltage indicates a binding or stalled pump motor.

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 ABS indicator illuminates.
    • The Traction Control indicator illuminates.
    • The driver information center (DIC) displays Service Stability System.

Conditions for Clearing the DTC

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

Diagnostic Aids

    •  The pump motor may be mechanically stuck.
    •  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 circuits listed below and ground.
  3. •  Terminal 45
    •  Terminal 16
    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+ circuits listed below and ground.
  5. • Terminal 31
    • Terminal 2
    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, replace the BPMV.
  6. If all circuits test normal, replace the BPMV and verify DTC does not reset. If the DTC resets replace the EBCM.

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