• | 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+ Terminal 1 | C0110 03 | C0110 04 | -- | C0110 61 |
Ground Terminal 13 | -- | C0110 04 | -- | C0110 61 |
Ground Terminal 38 | -- | C0110 04 | -- | 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 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. |
• | System and ignition voltage is above 9 volts. |
• | The system enable relay is ON. |
• | Ignition ON. |
• | System and ignition voltage is above 9 volts. |
• | The system enable relay is ON. |
• | The pump motor has been commanded OFF for 2 seconds. |
• | Ignition ON. |
• | The system enable relay is ON. |
• | The pump motor has been commanded ON, OFF and ON again. |
The EBCM detects an open in the pump motor driver or supply when when the motor is supposed to be turned on and if the motor feedback is below 50% of the system voltage for 10 ms,
The EBCM detects an open in the pump motor circuit when the feedback voltage remains greater than 0.75 volt for more than 50 msec.
The pump motor continues to rotate briefly after activation creating a feedback voltage. The EBCM sets the code if the measured feedback voltage indicates an open circiut, binding or stalled pump motor.
• | The EBCM disables the antilock brake system (ABS), traction control and StabiliTrak for the duration of the ignition cycle. |
• | A DIC message and/or a warning indicator may be displayed. |
• | The condition for the DTC is no longer present. |
• | Operate the vehicle at speeds greater than 15 km/h (10 mph) to complete the self test, and the EBCM will turn off the ABS indicator. |
• | The EBCM clears the history DTC when a current DTC is not detected in 40 consecutive drive cycles. |
Antilock Brake System Schematics
Control Module References for scan tool information
• | Terminal 25 |
• | Terminal 1 |
⇒ | 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. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for EBCM replacement, setup, and programming |