Powertrain, generic (extended)

P266B "A" Rocker Arm Actuator Position Sensor Circuit Range/Performance (Bank 2)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

For bank 2, P266B means the position reported for actuator A is electrically valid but does not match what was commanded or changes too slowly. CARB expects variable lift monitors to notice when the commanded position is missed or reached too late, and a sensor whose reading drifts from the real actuator position defeats both. No manufacturer publishes P266B; on the bank 1 side Toyota's comparable experience with P265B on Valvematic engines ended in recalibration or a replaced lift controller, which illustrates that software and mechanics can both be at fault. Check sensor mounting, linkage wear and actuator movement on that bank before replacing parts.

Likely causes

Bank 2 actuator or linkage binding
Sensor reading drifting from the true position
Control software calling for an update

Symptoms

  • MIL on after a drive cycle
  • Uneven running between the banks
  • Hesitation under load

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–1,300
Time0.5–4.5 h

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

Parts involved

rocker arm position sensor a b2actuator mechanism

Related codes

P266AP2656P264B

References: law.cornell.edu, static.nhtsa.gov, static.nhtsa.gov.