OBD-II code · Network

U05A8 Invalid Data Received From NOx Sensor C

A receiving module detected implausible data from NOx sensor C (smart sensor with own ECU). NOx concentration or pumping current values fail plausibility checks and are rejected.

Is it safe to drive with U05A8?

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

Common causes

  • Most likelyModule internal fault or sensor input drift
  • PossibleSoftware version mismatch after replacement
  • 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
0.5–3 h
Emissions test
Likely to fail
After the fix
A drive cycle is needed before the light stays off
Parts involved
Nox Sensor C

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