Powertrain, generic (extended)

P265E "B" Rocker Arm Actuator Position Sensor Circuit Intermittent/Erratic (Bank 1)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Here the bank 1 position signal for actuator B is neither stuck low nor high; instead it jumps, flickers or briefly vanishes faster than the mechanism could physically move. The engine controller compares successive readings and flags P265E when the rate of change or the number of dropouts exceeds what a motor-driven lift mechanism can produce. Typical culprits are fretting corrosion on the terminals, a conductor broken inside its insulation that only opens under vibration, or electrical noise from nearby ignition wiring. CARB asks for such signal quality checks on valve lift inputs. No manufacturer documents P265E publicly. The fault may come and go with temperature and road surface; the lift controller can hunt or fall back to a fixed setting.

Likely causes

Fretting corrosion on sensor B terminals
Conductor broken inside its insulation, opening under vibration
Interference from ignition or other high-current wiring

Symptoms

  • MIL on and off over several trips
  • Surging or uneven power delivery

Repair estimate

DifficultyHardWorkshop job
Parts and labour€60–1,200
Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

rocker arm position sensor b b1wiring harness

Related codes

P265AP265BP265DP264E

References: law.cornell.edu, en.wikipedia.org.