OBD-II code · Network

U0032 Vehicle Communication Bus A (+) High

The communication bus A high-side line (CAN-H or equivalent) is at a higher voltage than allowed. Likely short to power or a transceiver fault that pulls the line high.

Is it safe to drive with U0032?

The car may go into limp mode (reduced power). Get it diagnosed before a long trip.

Common causes

  • Most likelyBus high line shorted to battery
  • PossibleTransceiver in one node failed
  • Less likelyGateway module routing CAN messages incorrectly

Symptoms

  • Multiple warning lights may illuminate
  • Affected modules may go into limp mode or shut down
  • Specific functions inoperative depending on module
  • Diagnostic tools may show communication faults

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
1–6 h
Emissions test
Usually unaffected
Parts involved
Bus A Wiring, Bus A Transceiver

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.