Powertrain, generic (extended)

P264B "A" Rocker Arm Actuator Position Sensor Circuit Range/Performance (Bank 1)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

Range/Performance means the bank 1 feedback sensor for actuator A delivers a signal inside its electrical limits that still does not fit what the engine expects, for example a position that lags or overshoots the commanded one, or that fails to move when the actuator is driven. CARB requires valve lift systems to catch target errors and slow response before emissions exceed set limits. No manufacturer documents P264B publicly; the closest documented case is Toyota's P265B on Valvematic engines (2014 Corolla, 2018–19 C-HR, 2020 Corolla), cured by ECM reprogramming or a new continuously variable lift controller. Worn linkage, a loose sensor, or a dragging actuator are plausible causes.

Likely causes

Actuator or linkage moving sluggishly
Sensor loose or misaligned on its mount
Control software needing an update

Symptoms

  • MIL on after a drive cycle
  • Hesitation or uneven power delivery
  • Idle speed fluctuating

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–1,200
Time0.5–4 h

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

Parts involved

rocker arm position sensor a b1actuator mechanism

Related codes

P264AP2646P266BP265B

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