OBD-II code · Network

U0076 Control Module Communication Bus "C" Off

A control module has shut its bus C interface off because the bus is non-functional. Bus C is typically a tertiary CAN or LIN segment used for diagnostic or specialized subsystems.

Is it safe to drive with U0076?

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

Common causes

  • Most likelyBus C line shorted to supply or ground
  • PossibleOne failing module pulling the bus down
  • 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
1–8 h
Emissions test
Usually unaffected
Parts involved
Can Bus Wiring, Control Module

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