C0403 – AWD Oil Filter Reverse Valve Stuck Open

C0403 Possible Symptoms

Anti-Lock Brake System (ABS) Warning Light ON,Engine Light ON (or Service Engine Soon Warning Light)

C0403 Possible Causes

Faulty AWD Oil Filter Reverse Valve,AWD Oil Filter Reverse Valve harness is open or shorted,AWD Oil Filter Reverse Valve circuit poor electrical connection

C0403 Description

The differential clutch pump delivers hydraulic oil pressure to the rear drive clutch solenoid valve and the rear differential clutch solenoid valve. The pump is mounted to the torque transfer device housing. The pressure of the system is calculated by the rear differential clutch control module which monitors the differential clutch pump current levels. When the pressure reaches approximately 3200 kPa (464 psi), the rear differential clutch control module determines that the system pressure has been obtained and deacvitates the differential clutch pump. If a voltage is detected after a predetermined time limit when the pump has been deactivated an error is detected. This condition indicates the pump is spinning backwards.