Circuit Description
The system relay is energized when the ignition is ON. The system relay supplies voltage to the valve solenoids and the pump motor. This voltage is referred to as the system voltage. The electronic brake control module (EBCM) microprocessor activates the valve solenoids by grounding the control circuit.
Conditions for Running the DTC
| • | The system voltage is greater than 8 volts. |
| • | The ignition voltage is greater than 9 volts. |
Conditions for Setting the DTC
The commanded state of the driver and the actual state of the control circuit do not match for 0.03 seconds.
Action Taken When the DTC Sets
| • | The EBCM disables the ABS for the duration of the ignition cycle. |
| • | The ABS indicator turns ON. |
| • | For DTCs C1265 and C1267, the red Brake warning indicator turns ON. |
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 solenoid valve circuit is internal to the EBCM. The solenoid valve circuit is not diagnosable external to the EBCM. The DTC sets when there is a malfunction in the solenoid circuit internal to the EBCM.
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | |||
1 | Did you perform the ABS Diagnostic System Check? | Go to Step 2 | |
Does the DTC reset as a current DTC? | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | |
3 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Did you complete the repair? | Go to Step 4 | -- |
4 |
Does the DTC reset? | Go to Step 2 | System OK |
