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).

Tech notes

There is a factory service bulletin for the P1388 code on Jaguar model S type. The factory recommends reprogramming the Powertrain Control Module (PCM) to repair the problem.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P1388 JAGUAR Description

The variable camshaft timing solenoid effects the inlet camshaft timing only. The actuator is a helical spline type, which is engine oil driven. It provides 50 degrees of rotation for camshaft adjustment under different types of engine torque and load conditions.

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.

JAGUAR Technical Service Bulletins for P1388 code