Powertrain, generic (extended)

P266D "A" Rocker Arm Actuator Position Sensor Circuit High (Bank 2)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P266D is logged when the bank 2 position feedback of rocker arm actuator A climbs above its upper limit. Typical reasons are an interrupted sensor ground, a signal wire chafed through onto a supply line, or corrosion that raises resistance. Since the value no longer represents a reachable actuator position, the engine controller discards it. No manufacturer documents P266D publicly; the requirement to detect it comes from CARB's monitoring rules for variable valve lift components. Only engines with position-sensed actuators on both banks could ever set it. Diagnosis starts with reference voltage and ground at the bank 2 sensor plug. Related: P266C, P264D.

Likely causes

Interrupted ground of the bank 2 sensor
Signal wire chafed onto a supply line
Corroded terminals raising circuit resistance

Symptoms

  • MIL on
  • Lift on bank 2 frozen
  • Reduced power

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–650
Time0.5–3 h

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

Parts involved

rocker arm position sensor a b2wiring harness

Related codes

P266AP266CP264D

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