P2645"A" 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
- Engines that switch valve lift or deactivate cylinders through their rocker arms use an actuator, usually an oil control solenoid, to send oil to the locking pins. P2645 means the engine controller sees the drive circuit of actuator A on bank 1 as open: the state it commands and the state it reads back on the line disagree. GM's 2015 four-cylinder table 15OBDG05 runs this check wherever VVL hardware is fitted, needs more than 11 V, counts 100 failures within 120 samples taken every 250 ms and sets a Type A fault with the MIL on the first trip. P2648 and P2649 cover shorts to ground and to power. The engine stays in its default lift, so power at high revs or economy suffers.
- What you may notice
- MIL on, often on the first trip
- No change to high lift, weak pull at high engine speed
- Cylinder deactivation or economy mode no longer engages
- Likely causes
- LikelyOpen coil in the rocker arm oil control solenoid
- PossibleLoose, corroded or oil-soaked solenoid connector
- PossibleBroken wire in the control or supply line
- RareFaulty output driver 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.