C0278

DTC C0278:

DTC C0278

Circuit Description
The valve relay is part of the electronic brake control module (EBCM). The EBCM turns ON the valve relay when the ignition switch is in the ON position and no malfunction exists in the ABS. The valve relay provides power to the antilock brake system (ABS) solenoid valves.

Conditions for Running the DTC
DTC C0278 can be set anytime the ignition switch is turned to the ON position.

Conditions for Setting the DTC
The EBCM detects that the valve relay is OFF when actually the EBCM commanded the valve relay ON.

Action Taken When the DTC Sets
^ The ABS is disabled.
^ The ABS warning indicator turns ON.

Conditions for Clearing the DTC
The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

Diagnostic Aids
Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.
The following are possible causes of the malfunction:
^ An open or high resistance in the battery positive voltage circuit
^ An open or high resistance in the motor ground circuit
^ An internal EBCM malfunction
If an intermittent malfunction exists, refer to Testing for Intermittent and Poor Connections in Symptoms. A Symptoms - Antilock Brake System

Test Description
The number below refers to the step number on the diagnostic table.
2. This step determines if the DTC is current.