U041DInvalid Data Received From Rocker Arm Control Module B
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- U041D is the counterpart for rocker arm control module B, used where the switching of rocker arms is split, for instance by cylinder bank. The code tells that the engine controller still receives B's messages, but their lift or lock status cannot be trusted. Comparing with U041C helps: B alone points to that module, its harness branch or its solenoids, both together to the shared supply or the bus. No manufacturer documents U041D publicly and no thresholds are known. CARB requires monitoring of variable valve lift and plausibility checks of digital inputs. Likely effects: MIL, cylinders on the B side held in full-lift mode, higher fuel use and perhaps rough running. U011C is lost contact.
- What you may notice
- Check engine light
- Uneven running or higher fuel use
- Likely causes
- PossibleSwitching solenoid or oil supply on the B side faulty
- PossibleRocker arm control module B internally faulty
- RareShared supply or bus fault (then usually with U041C)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.