U0063 code meaning
Vehicle Communication Bus D (-) Shorted to Bus D (+)
What U0063 means
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.
U0063 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0063
- All modules on Bus D unreachable at once
- Several warning lamps or fallback modes
Common causes of U0063
- Most likelyHarness crushed so that both Bus D wires touch
- PossibleWater in a splice or connector bridging the pair
- Less likelyDamaged transceiver shorting its two bus pins
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Bus d wiring
What each part of U0063 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 63 | The exact fault in that area. |
What to do next
- Note U0063 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 U0063
What does U0063 mean?
U0063 means "Vehicle Communication Bus D (-) Shorted to Bus D (+)". U0063 covers a short circuit between both conductors of Vehicle Communication Bus D. It is a generic code, so it means the same on every make.
Is it safe to drive with U0063?
Drive gently and only to a workshop. With U0063 the car can go into limp mode (reduced power) to protect itself.
Will U0063 fail an emissions test?
U0063 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 U0063 to fix?
Difficulty: hard. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will U0063 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.