U007BControl Module Communication Bus I Off
- Generic OBD-II code · Network
- How the car detects it
- U007B is tied to no published manufacturer use; a Bus I only exists on vehicles split into many separate networks. The cause need not sit in the wiring at all. Onsemi describes a node whose transmit pin cannot produce a dominant level: every start-of-frame attempt fails and raises the error counter by eight, after 17 attempts it is error passive and shortly afterwards bus off, although the remaining bus may keep running normally. A damaged transceiver, a supply dip at the module or a cracked solder joint can therefore produce U007B in a single module only. If the code returns after clearing, check that module's power and ground under load and swap it against a known good unit before opening the harness.
- What you may notice
- Only the reporting module's functions drop out
- Code returns soon after clearing
- Likely causes
- PossibleTransceiver in the reporting module unable to drive the bus
- PossibleWeak supply or ground at the reporting module
- RareShort or open in the Bus I wiring
- Repair
- Hard · Usually a job for a workshop.Typical cost: €80 – €1,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.