U009DVehicle Communication Bus J
- Generic OBD-II code · Network
- Can trigger limp mode
- How the car detects it
- U009D covers Vehicle Communication Bus J in general, the tenth letter, and like I it has only this code and a performance code in the list, so open or shorted lines also end up here. No public bulletin names the network behind J, and no manufacturer documents U009D publicly. CARB's requirement for a separate code when a digital input stops communicating is the regulatory basis. Faults that appear after parking deserve attention. Nissan points out that with the key off and the network asleep both CAN wires read 0 V, so voltages must be measured with the bus awake. NXP notes that a single frame at a 500 kbit/s rate may not be enough to wake its TJA1043 reliably, and asks for two in a row. A module that wakes late can therefore look like a bus fault.
- What you may notice
- Functions of Bus J modules missing after start
- Lost-communication codes, sometimes only after parking
- Likely causes
- LikelyOpen or shorted wire on Bus J
- PossibleModule not waking or waking late
- PossibleSupply or ground fault at a Bus J module
- Repair
- Hard · Usually a job for a workshop.Typical cost: €50 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.