OBD-II code · Network

U019D Lost Communication With Direct Ozone Reduction Catalyst Temperature Sensor

ECU lost communication with the direct ozone reduction (DOR) catalyst temperature sensor. A communication loss with this module breaks any function relying on its data — diagnostic tools may show 'no response' and dependent modules can fall into limp mode.

Is it safe to drive with U019D?

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

Common causes

  • Most likelySensor unpowered or wiring broken
  • 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
Often, with basic tools
Typical labour
0.5–2 h
Emissions test
Likely to fail
After the fix
A drive cycle is needed before the light stays off
Parts involved
Dor Catalyst Temp Sensor, Can Bus

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