OBD-II code · Network

U0302 Software Incompatibility with TCM

A control module has detected that its software/calibration is incompatible with the transmission control module. Often appears after a TCM swap or partial flash.

Is it safe to drive with U0302?

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

Common causes

  • Most likelySoftware/calibration mismatch with TCM
  • PossibleUsed TCM from different vehicle fitted
  • 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
0.5–3 h
Emissions test
Usually unaffected
Parts involved
Tcm, Control Module

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