Network, generic

U0063 Vehicle Communication Bus D (-) Shorted to Bus D (+)

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

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.

Likely causes

Harness crushed so that both Bus D wires touch
Water in a splice or connector bridging the pair
Damaged transceiver shorting its two bus pins

Symptoms

  • All modules on Bus D unreachable at once
  • Several warning lamps or fallback modes

Repair estimate

DifficultyHardWorkshop job
Parts and labour€60–800
Time1–5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

bus d wiring

Related codes

U0036U0045U0054U0055U0072

References: onsemi.com, nxp.com, ti.com.