U007CControl Module Communication Bus J Off
- Generic OBD-II code · Network
- How the car detects it
- For U007C no manufacturer publishes a use; a Bus J only exists where the electrical architecture splits the vehicle into ten or more CAN segments. Bus off is self-healing by design: once the controller has seen 128 sequences of 11 recessive bits it may rejoin, as onsemi explains, and the error counters start again from zero. A short-lived short circuit, a loose pin or a voltage dip during cranking can therefore leave U007C as a history code while everything works again by the time the car reaches the workshop. Such intermittent cases need the fault reproduced, for instance by flexing harness sections and connectors of Bus J while watching the module's communication status. Replacing modules on a history code alone rarely helps.
- What you may notice
- Stored history code without a current complaint
- Brief, self-clearing dropouts of single functions
- Likely causes
- PossibleLoose pin or connector on Bus J opening briefly
- PossibleVoltage dip during engine cranking
- RareHarness chafe causing brief shorts on Bus J
- Repair
- Hard · Usually a job for a workshop.Typical cost: €60 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.