DTC C0278: Open in ABS Solenoid Relay Circuit; DTC C0279: Short in ABS Solenoid Relay Circuit: Description

WARNING: This page is about a different car, the 2009 Lexus IS 350 and 2009 Lexus IS 250. However, it is still accessible from the selected car via links, so may be relevant.

The ABS solenoid relay supplies power to the ABS solenoid and TR(A)C solenoid.

The solenoid relay is turned on 1.5 seconds after the engine switch is turned on (IG), and is turned off if an open or short in the solenoid is detected by self diagnosis performed when the vehicle starts running.

The ABS solenoid relay is housed in the skid control ECU in the actuator assembly.

DTC Code	DTC Detection Condition	Trouble Area
C0278	Either of the following is detected: Both of the following conditions continue for 0.2 seconds or more. The IG1 terminal voltage is 9.5 V or more. The solenoid relay contact is open when the relay is ON. Both of the following conditions continue for 0.2 seconds or more. The IG1 terminal voltage becomes lower than 9.5 V when the relay is turned on. The relay contact remains open.	ABS2 fuse ABS solenoid relay circuit Brake actuator assembly (ABS solenoid relay)
C0279	Immediately after the engine switch is turned on (IG), the solenoid relay contact is closed for 4 seconds when the relay is turned off.	ABS solenoid relay circuit Brake actuator assembly (ABS solenoid relay)