P266D

Code

Generic P — Powertrain

A Rocker Arm Actuator Position Sensor Circuit High Bank 2

Brand: Generic

Type: P — Powertrain

Views: UK: 29 EN: 58 RU: 45

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Page language: EN

Causes

Short to battery/12 V on the position sensor signal wire
Open or shorted wiring harness or poor connector connection to sensor
Defective rocker arm actuator position sensor
Faulty rocker arm actuator (positioner solenoid/valve) or internal mechanical binding
Low/contaminated engine oil or incorrect oil pressure affecting actuator operation
Faulty ECM or internal driver circuit

Symptoms

Malfunction Indicator Lamp (MIL) illuminated
Reduced engine performance or limp mode
Rough idle or hesitation under load
Cam timing related drivability faults or misfires
Related cam/valve timing DTCs may also be present

What to check

Read and record freeze frame and all related DTCs/new codes before clearing
Scan live data: monitor rocker arm actuator position sensor voltage and compare to expected values and to the other bank
Check oil level and condition; confirm oil meets manufacturer specification and is not heavily contaminated
Visually inspect wiring and connector for Bank 2 sensor for damage, corrosion, loose pins or oil intrusion
Backprobe the sensor connector and measure signal voltage with ignition on and engine running as applicable
Measure continuity and for shorts between sensor signal, 5 V reference (or supply), and battery positive

Signal parameters

Typical position sensor signal range: ~0.0–5.0 V (manufacturer dependent)
High condition threshold: sensor voltage above ~4.5 V (varies by vehicle)
Reference/supply: usually an internal 5 V reference or sensor supply from ECM
Signal should vary smoothly as the actuator changes position; stuck or constant high voltage indicates fault
If sensor is PWM type, expect a duty cycle range 0–100% corresponding to actuator position (refer to factory specs)

Diagnostic algorithm

Retrieve freeze frame data and related DTCs. Note when the code set and any conditions (oil temp, RPM).
Visually inspect the Bank 2 rocker arm actuator position sensor connector and wiring for damage, corrosion, oil intrusion and loose terminals.
With ignition ON (engine off) backprobe the sensor signal, reference and ground pins. Verify reference supply voltage (typically ~5 V) and that signal is not tied to battery voltage or stuck high.
Start the engine and observe the live sensor value. Confirm the signal changes with engine operation and compare to the same sensor on Bank 1 (if available).
Check for continuity and shorts: test resistance between signal wire and battery positive (short to 12 V), and signal wire to ground (short to ground). Repair any damaged wiring found.
Check oil level and condition; if oil is low or heavily contaminated, correct and retest since low pressure can affect actuators.
If wiring and supply are good, command the rocker arm actuator/solenoid (if supported by scan tool) and confirm the sensor responds. If commanded movement does not change the sensor reading, suspect actuator or sensor.
If suspect sensor, replace the Bank 2 rocker arm actuator position sensor and clear codes. Re-test to see if code returns.
If code persists after sensor replacement and wiring checks, consider testing or replacing the actuator/solenoid and, if required, perform ECM bench tests or replacement per factory procedure.
After repairs, road test and verify no recurrence of the code and that engine performance is restored.

Likely causes

Corroded or loose connector at the position sensor on bank 2
Pinched/damaged signal wire shorted to ignition power
Failed sensor producing a stuck-high voltage output
Actuator solenoid stuck closed/open causing sensor to read extreme position
Contaminated oil causing actuator to stick and sensor to report unexpected voltage

Fault status

⚠️ Status

Circuit High — Rocker Arm Actuator Position Sensor Bank 2 signal voltage is above the expected range. Diagnostic trouble code stored; may be current or intermittent.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.5-3.0 hours