U011BLost Communication With Rocker Arm Control Module A
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- U011B covers the first rocker arm control module. On overhead-cam engines that shut cylinders down or change valve lift, a solenoid routes engine oil to unhook a pin coupling two rocker arms; the cam-driven arm then moves on its own and the valve stays shut. Where a maker hands this switching to a dedicated controller, the engine controller sets U011B when that unit's messages stop. No manufacturer documents the code publicly. CARB requires lost digital communication to be coded separately and also obliges makers to supervise systems that vary valve timing or lift. U011C is the second module, U041C stands for invalid data from this one. Expect the MIL, switching of valve lift or cylinder deactivation locked out and higher fuel use.
- What you may notice
- MIL on
- Cylinder deactivation or valve lift switching inactive
- Higher fuel consumption
- Likely causes
- LikelyRocker arm module without power or ground
- PossibleOil-soaked or heat-damaged connector on the cylinder head
- PossibleDamaged CAN wiring between module and engine controller
- RareRocker arm control module internally faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.