• | 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. |
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 |
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.
• | Ignition ON. |
• | Initialization is complete. |
• | 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). |
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.
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.
• | The EBCM disables the ABS for the duration of the ignition cycle. |
• | The ABS indicator illuminates. |
• | 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. |
The pump motor is integral to the BPMV. The pump motor is not serviceable. Inspect the power and ground circuit connections.
Antilock Brake System Schematics
Antilock Brake System Connector End Views
Scan Tool Data List for scab tool information
Ignition ON, perform the Pump Motor Test with a scan tool and listen/feel the motor running.
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
⇒ | 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. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for EBCM replacement, setup, and programming |