OBD-II code · Network

U030C Software Incompatibility With Reductant Quality Module

A module reports a software version mismatch with the reductant quality module — 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 U030C?

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
Likely to fail
Parts involved
Reductant Quality Module

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