Powertrain, generic (extended)

P265C "B" Rocker Arm Actuator Position Sensor Circuit Low (Bank 1)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

The angle or position sensor of rocker arm actuator B, bank 1, normally works inside a voltage band that never touches the lower rail. If the reading falls below that band, the engine controller logs P265C, because a value near zero cannot correspond to any real actuator position. Possible reasons are a signal conductor grounded through damaged insulation, a supply feed that has dropped out, or an internal sensor defect. CARB treats out-of-range low signals of valve lift inputs as circuit faults to be detected. No carmaker documents P265C publicly; Toyota's published Valvematic cases concern the B sensor's range code P265B only. Without trustworthy feedback the controller generally parks the lift in a safe position. High side: P265D; range fault: P265B.

Likely causes

Sensor B signal wire grounded through damaged insulation
Sensor supply voltage missing
Internal fault in position sensor B

Symptoms

  • MIL on
  • Engine runs with fixed lift, less power

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–1,200
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

P265AP265DP265BP264C

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