OBD-II code · Network

U0014 Medium Speed CAN Communication Bus (-) High

CAN-Low on the medium-speed bus is shorted to battery voltage. The differential bus cannot work, body and comfort modules drop out of the network.

Is it safe to drive with U0014?

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

Common causes

  • Most likelyCAN-Low shorted to battery
  • 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 Low Wire, Module Connector

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