U011CLost Communication With Rocker Arm Control Module B
- 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
- U011C is the partner of U011B for rocker arm control module B, for example the controller of the second cylinder bank or of a second group of switchable rocker arms where the task is split across two units. The engine controller expects cyclic status from it, such as the confirmed lock state per cylinder, and records U011C once those frames fail to arrive. No manufacturer documents this code publicly, and it remains open which production engines use a separate B module at all; the entry relies on CARB's call for separate lack-of-communication codes and its monitoring rules for valve lift and control. Invalid data from this module is U041D. Without the B unit the affected cylinders usually stay in full-lift mode: MIL, possibly uneven running and more fuel.
- What you may notice
- MIL on
- Affected cylinders remain in full-lift mode
- Uneven running or higher consumption
- Likely causes
- LikelyModule B without power or ground
- PossibleContaminated or loose connector at the second cylinder head
- PossibleOpen or shorted CAN lines to module B
- RareRocker arm control module B 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.