U04BBInvalid Data Received From Switch Input Module B
- Generic OBD-II code · Network
- How the car detects it
- U04BB concerns the second switch input module. A receiving controller still hears module B on the bus, but the switch information inside its frames fails the plausibility, counter or checksum test. Where buttons are split across several housings, a modular layout like the one in a BCS Automotive Interface Solutions patent is typical: a main module identifies each attached satellite by a coded type and translates its signals for the CAN or LIN bus. A satellite reported with the wrong type or a coding mismatch after a part swap can produce exactly this kind of unusable data. No carmaker publishes a text for U04BB. U01B8 stands for total silence of module B. Expect individual buttons, often a group in one console or panel, to stop responding.
- What you may notice
- A group of buttons in one panel not responding
- Functions switching on by themselves or not switching off
- Likely causes
- LikelyReplacement switch module of the wrong variant or not coded to the vehicle
- PossibleSwitch input module B internally faulty
- RareLoose or corroded plug between satellite and main module
- 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.