DTC C0278/11 Open in ABS Solenoid Relay Circuit; DTC C0279/12 Short to B+ in ABS Solenoid Relay Circuit: Description

WARNING: This page is about a different car, the 2008 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.

The solenoid relay supplies power to the ABS solenoid and TRAC solenoid.

After the ignition switch is turned ON, the vehicle speed has reached 6 km/h (4 mph) 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 alternator outputs being insufficient.

DTC DETECTION CONDITION AND TROUBLE AREA

DTC No.	DTC Detection Condition	Trouble Area
C0278/11	When either condition below is met: Both of following conditions continue for 0.2 seconds or more. IG1 terminal voltage between 9.5 V and 18.5 V. Solenoid relay contact open when relay on. Both of following conditions continue for 0.2 seconds or more. IG1 terminal voltage becomes 9.5 V or less when relay turned on. Relay contact remains open.	ABS2 H-fuse Wire harness (+BS circuit) ABS and TRACTION actuator
C0279/12	Immediately after ignition switch turned ON, solenoid relay contact closed for 0.2 seconds or more when relay off.	ABS2 H-fuse Wire harness (+BS circuit) ABS and TRACTION actuator

HINT:

DTCs C0278/11 and C0279/12: The skid control ECU begins to detect these DTCs when the vehicle speed exceeds 6 km/h (4 mph).