For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using the 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) or Traction Control System operation is required the EBCM activates the pump motor relay and battery power is provided to the pump motor.

### Conditions for Running the DTC

• | The ignition switch is in the ON position.

• | Initialization is complete.

### Conditions for Setting the DTC

• | Pump motor voltage is not present 100 milliseconds after activation of the pump motor relay.

• | Pump motor voltage is present more than 1 second with no activation of the pump motor relay within 5 seconds.

### Action Taken When the DTC Sets

• | The EBCM disables the ABS, TCS and dynamic rear proportion (DRP) for the duration of the ignition cycle.

• | The ABS indicator illuminates.

### Conditions for Clearing the DTC

The Electronic Brake Control Module (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. Inspect the power and ground circuits for proper connections.

### 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

Scan Tool Data List

### Circuit/System Verification

Clear the DTCs then drive the vehicle in a straight line at a speed greater than 20 km/h (13 mph). The DTC should not set.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the EBCM.
2. Ignition ON, 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.

3. Verify that a test lamp illuminates between the B+ circuit terminal 32 and ground circuit terminal 16.

⇒ | If the test lamp does not illuminate, test the ground circuit for an open or high resistance.

4. 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.

5. Connect the EBCM harness to the EBCM with the BPMV still separated.
6. Connect a test lamp between the pump motor circuits at the internal EBCM connector.
7. Ignition ON, perform the Pump Motor Test using the scan tool.

⇒ | If the test lamp does not illuminate replace the EBCM and BPMV.

8. If all circuits test normal, test or replace the BPMV.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• | Electronic Brake Control Module Replacement

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