OBD-II code · Network

U0015 Medium Speed CAN Communication Bus (-) Shorted to Bus (+)

CAN-High and CAN-Low on the medium-speed bus are shorted together. The differential signal collapses; body and comfort modules drop offline.

Is it safe to drive with U0015?

Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.

Common causes

  • Most likelyCAN-H/CAN-L harness short
  • Less likelyGateway module routing CAN messages incorrectly
  • Less likelyCAN terminating resistor (120 Ω) drifted out of spec

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
0.8–5 h
Emissions test
Usually unaffected
Parts involved
Can High Wire, Can Low Wire

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