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U0010

Medium Speed CAN Communication Bus

A fault on the medium-speed CAN bus has been detected. This bus (typically 125 kbit/s) connects body and comfort modules — BCM, climate, doors, infotainment. A failure usually disables comfort functions but leaves the powertrain operational.

  • Check engine light: Not always
  • Emissions related: No
  • Repair difficulty: hard

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

Common causes

Ordered by how often each turns out to be the cause.

  • MS-CAN line shorted to supply or groundCommon
  • One failing comfort module pulling the bus downPossible
  • Gateway module routing CAN messages incorrectlyLess likely

Parts involved

  • CAN Bus Wiring
  • Body Control Module

U0010 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.