OBD-II code · Powertrain (generic, extended)

P2ACD Reductant Temperature Sensor B Range/Performance

The reductant temperature B signal does not match plausibility checks against related signals. Sensor drift.

Is it safe to drive with P2ACD?

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

Common causes

  • Most likelySensor characteristic drifted
  • PossibleSensor mounting displaced from reference path
  • Less likelySensor element aged beyond calibration window

Symptoms

  • Check engine light or NOx warning on
  • AdBlue/DEF level or quality warning
  • Possible no-start countdown after ignore period
  • Failed emissions inspection (NOx)

Repair at a glance

Difficulty
Easy
DIY friendly
Often, with basic tools
Typical labour
0.3–1.5 h
Emissions test
Likely to fail
Parts involved
Reductant Temperature Sensor B, Wiring Harness, Ecm

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