Powertrain, generic (extended)

P25CA Intake Camshaft Actuator Park Lock Control Circuit/Open (Bank 1)

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

Some cam phasers carry a locking pin that holds the rotor in a fixed base or middle position for starting and while oil pressure is still building. Where that pin is released and engaged by its own solenoid, the controller supervises this extra circuit. P25CA reports that the lock control circuit for the intake phaser on bank 1 is open or otherwise not behaving electrically, so the lock can no longer be operated on command. GM's 2015 Volt and ELR table 15OBDG01 lists P25CA among the intake phaser fault groups that suspend the other cam phaser diagnostics; it gives no thresholds of its own. Passive designs such as BorgWarner's mid-position lock for Hyundai lack this circuit. Expect rough starts or idle and limited cam timing.

Likely causes

Open winding in the intake phaser lock solenoid

Connector off or terminal pushed back after engine work

Broken wire between module and lock solenoid

Symptoms

Check engine lamp on
Rough start or unsteady idle
Intake cam timing held at a default position, 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

intake cam phaser b1park lock solenoidwiring harness

References: gsi.ext.gm.com, borgwarner.com, law.cornell.edu.