P2650"B" Rocker Arm Actuator Control Circuit/Open (Bank 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- Some engines split rocker arm switching into two stages or groups, each fed by its own oil control solenoid; the second one is called actuator B. P2650 is logged when the engine controller finds the drive line of that B solenoid on bank 1 open, so switching the output on or off brings no matching electrical response. No carmaker publishes this code with limits. GM's 2015 four-cylinder table 15OBDG05 shows how the equivalent test for actuator A is built: a driver check that only runs above 11 V and fails after 100 bad readings out of 120. CARB requires such circuit checks for every output of a valve lift system. Shorts on the same line are reported as P2653 (ground) and P2654 (power). Until repaired, the stage served by solenoid B remains in its rest position.
- What you may notice
- Check engine light on
- Second switching stage never engages, less power or economy in that range
- Possibly no other noticeable change in driving
- Likely causes
- LikelyOpen winding in the B rocker arm oil control solenoid
- PossibleTerminal pushed out or corroded in the solenoid B connector
- PossibleWire chafed through near the valve cover or harness clips
- RareFailed output stage for solenoid B in the engine control module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.