P25E5

Code

Generic P — Powertrain

B Camshaft Position Control Performance Bank 1

Brand: Generic

Type: P — Powertrain

Views: UK: 22 EN: 25 RU: 21

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Page language: EN

Causes

Stuck, clogged, or leaking oil control valve (OCV)/solenoid for camshaft B
Failed camshaft phaser/actuator (mechanical binding or internal wear)
Low engine oil pressure or very dirty/contaminated oil
Damaged or shorted wiring/connectors to the OCV, cam actuator, or camshaft position sensor
Faulty camshaft position sensor or poor sensor signal (intermittent or out-of-range)
Stretched or jumped timing chain/belt, worn timing components

Symptoms

Check Engine Light (MIL) illuminated
Reduced engine power or hesitation on acceleration
Rough idle or intermittent misfire-like symptoms
Poor fuel economy and increased emissions
Unusual noise from timing cover area (rattling if chain slack)
Possible hard starting or stalling in severe cases

What to check

Read and record freeze frame and full DTC list with a scan tool
Check engine oil level and condition (visually inspect for sludge or contamination)
Verify battery voltage and primary power/ground to PCM and cam system circuits
Visual inspection of wiring and connectors for the OCV, cam actuator, and camshaft position sensor (corrosion, damage, loose pins)
Manually actuate OCV with a scan tool where supported and observe response
Check for other related codes (cam sensor, crank/cam correlation, oil pressure)

Signal parameters

Commanded camshaft position / target timing (degrees) from PCM
Actual/measured camshaft position (degrees) from camshaft position sensor or phaser feedback
OCV command duty cycle or on/off command (%) or millisecond on-time
OCV coil resistance (ohms) and current draw (mA/A)
Camshaft position sensor signal waveform (voltage vs time) and pattern
Engine speed (RPM) and load at time of fault

Diagnostic algorithm

Retrieve freeze frame, live data, and related codes. Note RPM, oil temp, and commanded vs actual cam angle at fault.
Perform a visual inspection of wiring/connectors to the OCV(s), camshaft actuator, and camshaft position sensor on Bank 1. Repair any damaged connectors or wiring.
Check engine oil level and inspect oil condition. If oil is low or contaminated, correct, change oil & filter, then clear codes and retest.
With a suitable scan tool monitor commanded vs actual cam position while varying engine speed; attempt to actuate the OCV/actuator from the tool and observe response.
Measure OCV coil resistance and compare to specification. Check for short to ground or open circuit. Verify proper supply voltage and ground at the connector with key on and engine running.
Capture camshaft position sensor waveform with an oscilloscope or scan tool. Verify clean, consistent signal and correct correlation to crankshaft sensor.
If the OCV, wiring, and sensor check OK but actuator does not move, remove and bench-test the cam phaser/actuator or replace the OCV as per manufacturer procedure.
Inspect timing chain/belt and tensioners for stretch, jump, or wear if mechanical timing error is suspected.
If all mechanical and electrical components test good, consider PCM driver fault — perform PCM power/ground checks and consult manufacturer technical service information before replacement.
After repairs, clear codes and perform a road test or relearn procedure as required by the vehicle to confirm the fault is resolved.

Likely causes

OCV electrical failure or internal blockage preventing oil flow to the phaser
Cam phaser stuck due to varnish/sludge from degraded oil
Open/short in OCV or cam sensor circuit or poor connector pin contact
Insufficient oil pressure (low level, pump, or internal engine wear) preventing actuator movement
Physical timing chain/belt jump or actuator/camshaft mechanical failure