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

Circuit/System Description

The pump motor is an integral part of the brake pressure modulator valve (BPMV), while the pump motor relay is integral to the electronic brake control module (EBCM). The pump motor relay is not engaged during normal system operation. When Antilock Brake System (ABS) operation is required the EBCM activates the pump motor relay and battery power is provided to the pump motor.

Conditions for Running the DTC

C0110 04

    • The ignition switch is in the ON position.
    • Initialization is complete.

C0110 61

    • The test is initiated once per ignition cycle, when the vehicle speed is greater than 8 km/h (5 mph), and a fault was set on the last ignition cycle.
    • The vehicle speed is greater than 20 km/h (13 mph), and the brake is not applied.
    • The vehicle speed is greater than 40 km/h (26 mph).

Conditions for Setting the DTC

C0110 04

The EBCM detects a low voltage in the pump motor supply circuit when the feedback voltage is less than 6 volts for more than 1.8 seconds, and the pump motor is not activated. The ground circuit is open, and the feedback voltage is greater than 0.93 volt for 1.8 seconds, the pump is not activated.

C00110 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 for the duration of the ignition cycle.
    • The ABS indicator turns ON.

Conditions for Clearing the DTC

    • The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
    • 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 BPMV. The pump motor is not serviceable. Inspect the power and ground circuits proper connections.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation Reference

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 5 ohm of resistance between the ground circuit terminal 16 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 1 and 32 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

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

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 00

C0110 00

--

--

Ground

--

C0110 00

--

--

Circuit/System Description

The pump motor is an integral part of the brake pressure modulator valve (BPMV), while the pump motor relay is integral to the electronic brake control module (EBCM). The pump motor relay is not engaged during normal system operation. When the antilock brake system (ABS) or traction control system (TCS) operation is required the EBCM activates the pump motor relay and turns the pump motor ON.

Conditions for Running the DTC

C0110 04

    • Ignition ON.
    • Initialization is complete.

C0110 61

    • The test is initiated once per ignition cycle, when the vehicle speed is greater than 8 km/h (5 mph), and a fault was set on the last ignition cycle.
    • The vehicle speed is greater than 20 km/h (13 mph), and the brake is not applied.
    • The vehicle speed is greater than 40 km/h (26 mph).

Conditions for Setting the DTC

C0110 04

The EBCM detects a short to ground or an open/high resistance on the B+ circuit.

C0110 61

    • The EBCM detects the pump motor runs continuously.
    • The EBCM detects the pump motor is binding or stalled.

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 EBCM sends a serial data message to illuminate the appropriate warning indicator/message.

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 is integral to the BPMV, and the pump motor relay integral to the EBCM.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation Reference

ABS Description and Operation

Electrical Information Reference

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

Scan Tool Reference

Control Module References for scan tool information

Circuit Verification

Ignition ON, perform the Pump Motor Test with a scan tool and listen/feel the Pump Motor turn ON and OFF.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the EBCM.
  2. Test for less than 5 ohms between the ground circuit terminal 16 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 terminal 1 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 ABS motor circuit fuse is open, test or replace the BPMV.
  6. If all circuits test normal, replace the EBCM. If the DTC resets, 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