Possible causes
– Cam timing improperly set
– Continuous oil flow to the VCT piston chamber
– VCT solenoid valve stuck open
– Camshaft advance mechanism binding (VCT unit).
– Continuous oil flow to the VCT piston chamber
– VCT solenoid valve stuck open
– Camshaft advance mechanism binding (VCT unit).
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P1388 MAZDA OBD Code Description
The comprehensive component monitor (CCM) monitors the VCT position for over-retarded camshaft timing. The test fails when the camshaft timing exceeds a maximum calibrated value or remains in a retarded position.