U04BCInvalid Data Received From Switch Input Module C
- Generic OBD-II code · Network
- How the car detects it
- With a third switch input module, addressing becomes a weak point. Several near-identical switch units often hang on one LIN line as slaves, and each needs its own node address, assigned either by part variant or by an auto-addressing routine at start-up. If two units end up with the same address, or a reply arrives with a bad LIN checksum, the master receives data it cannot assign and the controller records U04BC for module C. Nothing public ties this code to a specific make or to a fixed location in the car. U01B9 covers the case where module C does not answer at all, and U04BD, which follows in the list, belongs to the park lock module rather than to this series. Effects stay limited to the buttons wired to module C.
- What you may notice
- Buttons of module C ignored while other switch groups work
- Button presses assigned to the wrong function
- Likely causes
- PossibleTwo switch units with the same LIN node address after replacement or failed auto-addressing
- PossibleSwitch input module C internally faulty
- RareInterference on the shared LIN line, e.g. damaged insulation
- Repair
- Medium · Usually a job for a workshop.Typical cost: €0 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.