U0063Vehicle Communication Bus D (-) Shorted to Bus D (+)
- Generic OBD-II code · Network
- Can trigger limp mode
- How the car detects it
- U0063 covers a short circuit between both conductors of Vehicle Communication Bus D. On a CAN-type Bus D the receivers then measure no voltage difference, read every bit as recessive and cannot see any frame start; onsemi lists this short with those that block transmission completely. It is also one of the two fault classes, along with wire breaks, that NXP's TJA1041 bus diagnosis explicitly does not detect, so modules infer it from error counters and silent partners. A useful check uses the termination: with the battery disconnected, a healthy high-speed pair reads about 60 ohms between the wires, while this fault gives close to zero. If the short sits inside a module, unplugging modules one at a time brings the reading back. No manufacturer documents U0063 publicly.
- What you may notice
- All modules on Bus D unreachable at once
- Several warning lamps or fallback modes
- Likely causes
- LikelyHarness crushed so that both Bus D wires touch
- PossibleWater in a splice or connector bridging the pair
- RareDamaged transceiver shorting its two bus pins
- 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.