OBD-II code · Network

U031F Software Incompatibility With Accessory Protocol Interface Module

A module reports a software version mismatch with the accessory protocol interface module (APIM) — typically after replacing one of the modules without programming the new unit to match the rest of the network.

Is it safe to drive with U031F?

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

Common causes

  • Most likelyModule replaced without programming
  • PossibleWrong part number for the vehicle
  • 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
Medium
DIY friendly
Best left to a mechanic
Typical labour
0.5–2 h
Emissions test
Usually unaffected
Parts involved
Accessory Protocol Interface Module

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