P25D0

Code

Generic P — Powertrain

Exhaust Camshaft Actuator Park Lock Control Circuit/Open Bank 1

Brand: Generic

Type: P — Powertrain

Views: UK: 25 EN: 33 RU: 23

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Page language: EN

Causes

Broken or disconnected wiring in the park lock control circuit
Corroded, loose, or damaged connector at actuator or ECM
Failed exhaust camshaft actuator park-lock solenoid or actuator assembly
Blown fuse or power supply interruption to the VVT/actuator circuit
Poor engine ground or ECU ground issue
Internal ECM driver failure or software fault

Symptoms

MIL (Check Engine) illuminated
Possible limp mode or reduced engine power
Rough idle, hesitation or loss of low‑end torque
Hard starting or extended crank time in some conditions
Increased emissions or failed camshaft timing adaptation noted on scan tool

What to check

Read and record freeze-frame and live data with a capable scan tool (cam timing, actuator command, actuator feedback)
Confirm DTC is current and note mileage/conditions when set
Visually inspect wiring and connectors at the exhaust cam actuator (bank 1) and ECM for damage, corrosion, or loose pins
Check fuses and power supply circuits related to the VVT actuators
Perform a wiggle test of harness while monitoring live data and looking for intermittent changes
Measure continuity between actuator connector and ECM pin; check for shorts to battery and ground

Signal parameters

Control type: ECM-driven park-lock solenoid (on/off or PWM driver)
Supply voltage: battery voltage present on supply circuit when key on — verify at connector
Driver output: switching to ground or PWM from ECM when commanded (verify with oscilloscope/scan tool)
Actuator coil resistance: typically low ohms (consult OEM spec; an open reading indicates coil failure)
Expected behavior: when commanded, ECM output changes and actuator shows corresponding current draw or position change

Diagnostic algorithm

Use a scan tool to confirm P25D0 is current; record freeze frame, cam angle, and actuator commanded vs actual.
Inspect the exhaust cam actuator (Bank 1) connector and wiring for damage, corrosion, or disconnection; repair as required.
Check fuses/power feeds for the VVT/actuator circuits; restore any blown fuses and retest.
With ignition ON (engine off), measure voltage at the actuator supply pin and resistance of the coil; compare to OEM values. An open coil or no supply indicates electrical fault or failed actuator.
Check continuity from the actuator connector to the ECM pin; repair any open or high-resistance wiring. Check for short to voltage or ground if symptoms indicate.
If wiring and power/ground are good, command the actuator with a scan tool while monitoring voltage/current or use a scope to confirm ECM output waveform. If ECM does not switch output, suspect ECU driver or software.
If safe and per service manual, bench-test or apply battery power briefly to the actuator to verify movement (observe manufacturer safety precautions).
Inspect mechanically that the park-lock mechanism and actuator move freely and are not seized. Repair or replace actuator/park-lock if mechanically stuck.
After repairs, clear DTCs, perform relearn/adaptation procedures if required, and run closed-loop tests/road test to verify.
If wiring, power, and actuator are good but fault persists, consider ECM diagnostics or replacement per OEM guidance.

Likely causes

Damaged harness at valve cover or cylinder head (chafing/heat damage)
Pin/backside corrosion or bent pin in connector
Open coil windings in the actuator solenoid
Blown engine fuse or fusible link supplying actuator power
Park lock stuck mechanically due to carbon/valve train damage

Fault status

⚠️ Status

Exhaust camshaft actuator park-lock control circuit open detected on Bank 1: control output commanded but expected circuit response or feedback not detected.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.0 hours