• | 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 00 | C0110 00 | -- | C0110 61* |
Ground | -- | C0110 00 | -- | C0110 61* |
* Relay or Pump Mechanically Stuck |
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.
• | 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 short to ground or an open/high resistance on the B+ circuit or the ground circuit.
The EBCM detects the pump does not run when the relay is energized.
• | 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. |
• | 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, and the pump motor relay integral to the EBCM.
Antilock Brake System Schematics
Control Module References for scan tool information
Ignition ON, perform the Pump Motor Test with a scan tool and listen/feel for the relay clicking and the Pump to turn ON and OFF.
⇒ | 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 pump 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 |