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. |
This diagnostic procedure supports the following DTC:
DTC C1214 Solenoid Valve Relay Coil or Contact Circuit Open
• | The ignition voltage is greater than 10.8 volts. |
• | The system relay is commanded ON. |
• | For Criteria 2, one of the following conditions exists: |
- | The pump motor is OFF. |
- | During initialization, the pump motor is ON. |
One of the following conditions exists for 0.23 seconds:
The system voltage is less than 8 volts.
The difference between the ignition voltage and system voltage is greater than 1.9 volts.
If equipped, the following actions occur:
• | The EBCM disables the Antilock Brake System (ABS)/Traction Control System (TCS) 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 message center displays the Service Traction System message. |
• | The condition for the DTC is no longer present and the DTC is cleared with a scan tool. |
• | The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
The system relay is integral to the EBCM. The relay is not serviceable.
The number below refers to the step number on the diagnostic table.
Step | Action | Value | Yes | No |
---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
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 |
Does the DMM display the specified value? | OL | Go to Step 5 | Go to Step 4 |
4 | Replace the EBCM and the BPMV. Refer to Control Module References in Computer/Integrating Systems and Brake Pressure Modulator Valve Replacement . Did you complete the repair? | -- | Go to Step 6 | -- |
5 | Replace the EBCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the repair? | -- | Go to Step 6 | -- |
6 |
Does the DTC reset? | -- | Go to Step 2 | System OK |