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

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
B+ | C0110 04 | C0110 04 | -- | --
Ground | -- | C0110 04 | -- | --

Component | Condition | DTC
--- | --- | ---
Internal Pump Motor Relay | Mechanically Stuck in the ON or OFF Position | C0110 61

### 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

• | 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 low voltage in the pump motor B+ 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 illuminates.

### 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. The pump motor is not serviceable. Inspect the power and ground circuit connections.

### Reference Information

#### Schematic Reference

Antilock Brake System Schematics

#### Connector End View Reference

Antilock Brake System 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

Scan Tool Data List for scab tool information

### Circuit/System Verification

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

### 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.

⇒ | 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. If the circuit tests normal and the ABS motor circuit fuse is open, test or replace the BPMV.

4. 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.

• | Electronic Brake Control Module Replacement

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