U007FControl Module Communication Bus M Off
- Generic OBD-II code · Network
- How the car detects it
- U007F closes the range of bus-off codes that SAE runs from U0073 for Bus A to Bus M; the next code, U0080, already belongs to the general Bus F faults. No manufacturer publishes a use, and which physical network carries the letter M has to be read from the maker's service data. CARB only demands that missing digital communication be detected and stored separately, not how buses are named. One detail helps narrow the cause: according to Wikipedia, a sender whose frames simply go unacknowledged, for example because it is alone on the bus, keeps repeating them and reaches error passive, not bus off. U007F thus points to active disturbance, such as a shorted line or a node that cannot drive the bus. Begin at the storing module's supply, ground and connector.
- What you may notice
- Functions of the storing module unavailable
- Several warning messages or none, depending on the module
- Likely causes
- PossibleShorted line on Bus M
- PossibleA node unable to drive the bus, e.g. defective transceiver
- RarePoor supply, ground or connector contact at the storing module
- Repair
- Hard · Usually a job for a workshop.Typical cost: €60 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.