U0057 code meaning
Vehicle Communication Bus D (+) Open
What U0057 means
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.
U0057 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyHard
- Typical labor0.5 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0057
- Modules beyond the break unreachable
- Sporadic errors among the remaining modules
Common causes of U0057
- Most likely(+) wire of Bus D broken where the harness flexes
- PossibleConnector left unplugged or not latched after a repair
- PossibleBacked-out or spread terminal
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Bus d wiringModule connector
What each part of U0057 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 57 | The exact fault in that area. |
What to do next
- Note U0057 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U0057
What does U0057 mean?
U0057 means "Vehicle Communication Bus D (+) Open". U0057 indicates an interrupted (+) wire on Vehicle Communication Bus D. It is a generic code, so it means the same on every make.
Is it safe to drive with U0057?
U0057 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U0057 fail an emissions test?
U0057 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is U0057 to fix?
Difficulty: hard. A typical repair takes 0.5 to 5 hours of work. This is a job for a workshop.
Will U0057 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.