OBD-II code · Powertrain (generic, extended)

P2D5A Reductant Level Sensor A/B Correlation

The signals of the reductant level sensors A and B do not correlate within the calibrated tolerance. One sensor drifts or installation offset between channels.

Is it safe to drive with P2D5A?

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

Common causes

  • Most likelyOne sensor characteristic drifted
  • PossibleHarness incorrectly swapped between channels

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
0.3–2 h
Emissions test
Usually unaffected
Parts involved
Reductant Level Sensor A, Reductant Level Sensor B, Scr Module

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