For 1990-2009 cars

### 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 for proper connections. With ignition OFF, separate the EBCM from the BPMV. Inspect the EBCM to BPMV connector for conditions such as damage, corrosion, or presence of brake fluid. If connector corrosion or damage is evident, replace BPMV and/or EBCM as necessary. If brake fluid is present, replace both BPMV and 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

### Circuit/System Verification

With scan tool installed ignition ON clear the DTCs, command the ABS pump motor ON and OFF with a scan tool. Monitor the operation of pump motor turns on and off. Also, drive the vehicle in a straight line at a speed greater than 20 km/h (13 mph). If the DTC did not set as a current DTC see diagnostic aids.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the EBCM.
2. Test for less than 1.0 ohm of resistance from ground circuit terminal 16 and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 1 and ground.

⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

4. Verify that a test lamp illuminates between the B+ circuit terminal 32 and ground.

⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

5. If all circuits test normal, test or replace the BPMV and EBCM assembly.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Brake Pressure Modulator Valve Replacement

• | Electronic Brake Control Module Replacement

• | Control Module References for EBCM replacement, setup, and programming