U0057Vehicle Communication Bus D (+) Open
- Generic OBD-II code · Network
- How the car detects it
- U0057 indicates an interrupted (+) wire on Vehicle Communication Bus D. Where Bus D is a two-wire CAN, such as the private chassis CAN Bentley files under that name, it is CAN-High. Apart from splitting the bus, a break changes the line itself: Texas Instruments describes high-speed CAN as a 120-ohm twisted pair terminated at both far ends, and warns against placing a terminator inside a node because the line loses it when that node is unplugged. A break that cuts one terminator off leaves part of the wire unterminated, so reflections can distort edges for the remaining nodes. The transceiver cannot detect the interruption itself (NXP). No manufacturer documents U0057 publicly. Look for connectors left open after repairs and conductors fractured where the harness flexes.
- What you may notice
- Modules beyond the break unreachable
- Sporadic errors among the remaining modules
- Likely causes
- Likely(+) wire of Bus D broken where the harness flexes
- PossibleConnector left unplugged or not latched after a repair
- PossibleBacked-out or spread terminal
- 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.