Powertrain, generic (extended)

P25D1 Exhaust Camshaft Actuator Park Lock Control Circuit Low (Bank 1)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P25D1 indicates that the control signal for the bank 1 exhaust phaser lock is too low, normally a grounded wire or a solenoid winding that leaks to ground. The exhaust side is the hotter one, so insulation that has hardened and cracked near the manifold or turbocharger is a typical finding. With the line grounded, the solenoid may stay powered and keep the pin retracted, or it never gets current, in which case the phaser stays locked. Either way the controller usually stops adjusting exhaust timing and falls back to a safe default. No public manufacturer document lists P25D1; the description follows the J2012 wording, CARB's requirement for circuit checks on output components and the general working of locking cam phasers.

Likely causes

Heat-cracked insulation grounding the lock wire
Shorted exhaust lock solenoid
Engine oil wicked into the connector

Symptoms

  • Check engine lamp on
  • Exhaust timing fixed, slightly less power

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–700
Time0.5–3 h

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

Parts involved

exhaust cam phaser b1park lock solenoidwiring harness

Related codes

P25D0P25D2P25D4P25CBP2090

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