P25CB

Code

Generic P — Powertrain

Intake Camshaft Actuator Park Lock Control Circuit Low Bank 1

Brand: Generic

Type: P — Powertrain

Views: UK: 27 EN: 37 RU: 29

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Page language: EN

Causes

Short to ground in park lock control wiring
Open or high-resistance wiring/connector between PCM and actuator
Corroded, pushed-back, or damaged connector pins at actuator or PCM
Faulty intake camshaft actuator / park lock solenoid (internal short or high resistance)
Blown fuse or poor power supply to actuator circuit
Faulty PCM or driver transistor (less common)

Symptoms

Malfunction Indicator Lamp (MIL)/Check Engine Light illuminated
Reduced engine performance or limp mode due to VVT disabled
Rough idle or hesitation under load
Loss of variable valve timing on intake Bank 1 (timing stuck in parked position)
Possible unusual engine noise during startup or valve actuation

What to check

Read and record freeze frame data and readiness status with a scan tool; note when the code sets (key on/engine running/after cranking).
Visually inspect wiring and connector for the intake camshaft actuator (Bank 1) for damage, corrosion, or pin push-out.
Check battery voltage (engine off and cranking) and inspect related fuses and relay for the cam actuator circuit.
Back-probe actuator connector and command the actuator with a scan tool while observing voltage; check for expected supply and driver signal.
Measure coil resistance of the actuator (manufacturer spec) and compare to expected range; check for short to ground or open.
Perform continuity check between actuator connector and PCM pins to verify no opens or shorts.

Signal parameters

Connector supply voltage (key ON, engine OFF): typically ~11–14 V (battery voltage) on the feed circuit
Driver/command signal when PCM actuates: may be a switched ground or switched positive — expected measurable change when commanded; a low condition is typically
Park lock solenoid coil resistance (typical range for many actuators): roughly 6–30 Ω (varies by manufacturer) — check OEM spec
Open-circuit condition: infinite/very high resistance between actuator terminals
Short-to-ground condition: near 0 Ω between control wire and chassis ground

Diagnostic algorithm

Verify the code: Use a scan tool to confirm P25CB is stored and record freeze frame and live data. Clear the code and attempt to reproduce.
Visual inspection: With engine off, inspect the Bank 1 intake camshaft actuator connector, wiring harness, and nearby components for chafing, heat damage, corrosion, or poor connections.
Power and ground check: Verify battery voltage at the actuator feed and check engine/PCM grounds related to cam actuator circuits; inspect and test any related fuses/relays.
Back-probe and command: Back-probe the actuator connector. Command the actuator ON/OFF with a scan tool and observe the voltage response at the harness. Note whether the circuit shows low voltage when the PCM commands a high state.
Coil resistance and shorts: With connector disconnected, measure coil resistance of the actuator and check for shorts to chassis ground or battery. Compare to OEM spec.
Wiring continuity: Check continuity between the actuator connector pins and the corresponding PCM pins. Check for high resistance, opens, or shorts to ground/power.
Wiggle and load test: With harness connected, wiggle the wiring while monitoring the signal and watch for code reappearance or intermittent changes.
Component substitution: If wiring and supply are good, substitute a known-good actuator (or swap with identical circuit if possible) to confirm faulty actuator vs PCM driver.
PCM driver check: If actuator and wiring test good but the circuit still reads low, test the PCM driver using OEM procedures or consult manufacturer diagnostic data; repair/replace PCM only after ruling out wiring and actuator.
Repair and verify: Repair any wiring faults, replace faulty actuator or PCM as justified, clear codes, and perform functional/road test to verify the repair. Re-scan for stored/pending codes.

Likely causes

Wiring shorted to ground at or near the actuator connector
Corroded/loose connector at the actuator (park lock solenoid)
Failed camshaft actuator/park lock solenoid coil
Open/poor ground or blown fuse for actuator power feed

Fault status

⚠️ Status

Intake camshaft actuator park lock control circuit low (Bank 1) — low voltage detected on the park lock/actuator control circuit. Check wiring, connectors, fuse/power, actuator coil, and PCM driver.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours