Circuit Description
The system relay is energized when the ignition is ON. The system relay supplies voltage to the solenoid valves and the pump motor. This voltage is referred to as the system voltage.
The electronic brake control module (EBCM) controls each solenoid valve by grounding the solenoid.
The EBCM controls the pump motor by grounding the control circuit. The pump serves 2 purposes:
| • | Transfers brake fluid from the brake calipers to the master cylinder reservoir during pressure decrease events. |
| • | Transfers brake fluid from the master cylinder reservoir to the brake calipers during pressure increase events. |
Conditions for Running the DTC
| • | The pump motor is commanded ON. |
| • | The system voltage is greater than 8 volts. |
Conditions for Setting the DTC
One of the following conditions exists for 0.16 seconds:
| • | With the commanded pump motor voltage less than the system voltage, the actual pump motor voltage is 3 volts less than the commanded voltage. |
| • | With the commanded pump motor voltage greater than the system voltage, the actual pump motor voltage is less than 8 volts. |
Action Taken When the DTC Sets
If equipped, the following actions occur:
| • | The EBCM disables the ABS/TCS/VSES for the duration of the ignition cycle. |
| • | The DRP does not function optimally. |
| • | The ABS indicator turns ON. |
| • | The Traction Off indicator turns ON. |
| • | The DIC displays the Service Stability System message. |
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present and the DTC is cleared with a scan tool. |
| • | 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 BPMV. The pump motor is not serviceable.
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Antilock Brake System Connector End Views | ||||
1 | Did you perform the ABS Diagnostic System Check? | -- | Go to Step 2 | |
2 |
Does the DTC reset? | -- | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems |
3 |
Is connector OK and cavity free of brake fluid? | -- | Go to Step 5 | Go to Step 4 |
4 |
Did you complete the repair? | -- | Go to Step 9 | -- |
Does the test lamp illuminate? | -- | Go to Step 8 | Go to Step 6 | |
6 |
Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 7 |
7 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Did you complete the repair? | -- | Go to Step 9 | -- |
8 | Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement . Did you complete the repair? | -- | Go to Step 9 | -- |
9 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
