Powertrain, generic (extended)

P2661 "B" Rocker Arm Actuator System Performance/Stuck Off (Bank 2)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P2661 is the functional check of rocker arm stage B on bank 2: although the solenoid circuit is electrically sound, the commanded switch did not happen or the confirmation (an oil pressure switch reading or a change in cam phaser or engine response) stayed too small. Bank 2 means the engine has two cylinder heads, so the fault concerns only half of the cylinders, which may show as a difference between the banks. No manufacturer documents P2661 publicly with test conditions; CARB requires valve lift systems to detect hydraulic and mechanical faults that keep them from reaching the target. Oil starvation in that head, a partly blocked oil gallery, a sticking spool or seized pins are likely. Bank 1 counterpart: P2651; electrical fault: P2660.

Likely causes

Low oil level or poor oil supply to the bank 2 head
Partly blocked oil gallery or screen on bank 2
Sticking solenoid spool or seized locking pins on bank 2

Symptoms

  • MIL after a completed drive cycle
  • Less power in the range where stage B should engage
  • Higher fuel consumption

Repair estimate

DifficultyMediumDIY possible
Parts and labour€50–900
Time0.5–4 h

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

Parts involved

rocker arm actuator b b2oil control valveoil supply

Related codes

P2662P2660P2651P2656

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