P25D4 Exhaust Camshaft Actuator Park Lock Control Circuit Low (Bank 2)

P25D4 reports a lock control line for the bank 2 exhaust phaser that is pulled down below its expected level. Grounding through damaged insulation, a solenoid with shorted turns or oil that has crept into the connector are the usual explanations. Because the exhaust manifold of the second bank radiates onto nearby harness sections, heat sleeving that has slipped out of place is worth checking. While the fault is active the controller cannot set the lock reliably and normally freezes exhaust timing on that bank. As with the other exhaust lock codes, there is no public manufacturer documentation; the account rests on CARB's circuit monitoring requirement and the operating principle of locking phasers. Repair is wiring work or a new solenoid.

Likely causes

Symptoms

• Check engine lamp on
• Bank 2 exhaust timing fixed

Repair estimate

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

Related codes

References: law.cornell.edu, en.wikipedia.org.