U05B9Invalid Data Received From Rear Radar Module C
- Generic OBD-II code · Network
- How the car detects it
- A third rear radar is only needed on vehicles whose rear coverage goes beyond the usual pair of corner sensors, for example to watch longer flanks or the area directly behind. No manufacturer publishes U05B9 or the position of a rear radar C, and its lost-communication partner U02B8 has no public bulletin either. Where letters are documented, they belong to the outer units: Mercedes-Benz uses rear modules A and B for the outer left and right sensors of the 2026 CLA electric and reports them, when unconfigured, with fault type 55. U05B9 would follow the same logic for a further sensor: frames arrive, the content is refused. Configuration, calibration after bumper work and the connector are the first checks. Blind spot or rear crossing alerts may be partly unavailable.
- What you may notice
- Rear assistance warnings partly unavailable
- Service message for driver assistance
- Likely causes
- PossibleRear radar C not configured or calibrated after replacement
- PossibleSensor position or cover changed by rear body repair
- RareWiring or connector fault at rear radar C
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.