C0278 Code: Meaning, Causes, and Symptoms | OBD2 Codes
C0278 – Open or Short Circuit in ABS Solenoid Relay Circuit
C0278 Possible Symptoms
Anti-Lock Brake System (ABS) Warning Light ON,Engine Light ON (or Service Engine Soon Warning Light)
C0278 Possible Causes
Blown Anti-Lock Brake System (ABS) Solenoid Relay Fuse,Faulty ABS Solenoid Relay,ABS Solenoid Relay harness is open or shorted,ABS Solenoid Relay circuit poor electrical connection,ABS Actuator (Skid Control ECU)
The solenoid relay supplies power to the Anti-Lock Brake System (ABS) solenoid and TRAC solenoid. After the ignition switch is turned on, the vehicle speed has reached 4 mph (6 km/h) and the solenoid is determined to be normal by the initial check self- diagnosis, the relay switches on. If any open or short circuits are detected, the relay switches off. These DTCs may be set if the voltage supply to the solenoid relay (+BS) falls below the DTC detection threshold due to the battery or generator outputs being insufficient.