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

Diagnostic algorithm

1. Retrieve all DTCs and freeze-frame data. Note vehicle conditions when code set (temp, RPM, oil temp).
2. Check oil level/quality. Correct low oil or change very contaminated oil before electrical diagnostics if oil-related symptoms present.
3. Perform visual inspection of the intake cam actuator (Bank 1) harness and connector for corrosion, bent pins, or damage. Repair as needed.
4. Verify power and ground at the actuator connector with ignition ON. Check for battery voltage on the supply terminal and a good ground reference.
5. Measure solenoid coil resistance at the connector (unplugged). Compare to specification; an open or very high reading indicates a failed solenoid.
6. Back-probe the control/driver pin and command the actuator ON/OFF with a capable scan tool while monitoring voltage/current. Observe for a change — if no change, suspect open circuit or failed solenoid.
7. If no control signal reaches the actuator, perform continuity check between the actuator control pin and the ECM driver pin. Repair any open/short in wiring.
8. Wiggle test wiring and connectors while monitoring live data to detect intermittent faults.
9. If wiring and actuator test good but no response, test or substitute the ECM driver according to manufacturer procedures (often a dealer-level procedure).
10. If mechanical seizure suspected (actuator electrical tests normal but phaser doesn't move), remove phaser/actuator for mechanical inspection and repair as required.
11. After repairs, clear codes and perform a relearn/initialization procedure if required by the manufacturer. Road test and re-scan to confirm the issue is resolved.