OBD-II code · Network

U0325 Software Incompatibility with Auxiliary Heater Control Module

The auxiliary heater module is running incompatible software. The pre-heater may not start or aborts operation early.

Is it safe to drive with U0325?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyIncompatible flash version
  • 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
Medium
DIY friendly
Best left to a mechanic
Typical labour
0.3–1.5 h
Emissions test
Usually unaffected
Parts involved
Auxiliary Heater

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