U0072Vehicle Communication Bus E (-) Shorted to Bus E (+)
- Generic OBD-II code · Network
- Can trigger limp mode
- How the car detects it
- U0072 describes the (-) and (+) wires of Vehicle Communication Bus E touching each other. On a high-speed CAN this ends communication: with the pair bridged there is no differential voltage, onsemi found transmission impossible, and NXP's TJA1041 note lists the short with the faults its bus diagnosis cannot detect. A fault-tolerant low-speed CAN degrades more gently. NXP's TJA1055 treats the short as a dominant level that never ends, confirms it in 0.3-1.6 ms, shuts down its CAN-Low driver and falls back to working over one wire, and returns to differential mode once the short is gone and the recessive state holds for a while. No manufacturer documents U0072 publicly. Separating connectors along the bus while measuring the resistance between the wires narrows the location down.
- What you may notice
- All modules on Bus E unreachable (high-speed type)
- Several warning messages, gateway reports lost communication
- Likely causes
- LikelyHarness crushed so that both Bus E wires touch
- PossibleWater in a splice or connector bridging the pair
- RareDamaged module input shorting its 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.