Powertrain, generic (extended)

P266A "A" Rocker Arm Actuator Position Sensor Circuit (Bank 2)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P266A is the basic circuit fault for the bank 2 position sensor of rocker arm actuator A. It only applies to engines that have a lift actuator with position feedback on each cylinder bank, which is rare; most switching rocker systems on V engines rely on oil pressure switches or none at all. No manufacturer documents P266A publicly, and even Toyota's Valvematic, which does use such feedback, is an inline design whose bulletins list a B code for its sensor. CARB still requires every electrical component of a lift system to be checked. If the controller loses this signal, it typically stops varying lift on bank 2, so power and refinement suffer.

Likely causes

Poor contact at the bank 2 sensor connector
Damaged wiring between sensor and engine controller
Failed bank 2 position sensor

Symptoms

  • MIL on
  • Lift on bank 2 no longer adjusted
  • Reduced power and smoothness

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–750
Time0.5–3.5 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

P266BP266CP266DP266EP2655P264A

References: law.cornell.edu, static.nhtsa.gov, en.wikipedia.org.