OBD-II code · Powertrain (generic, extended)

P20C6 Reductant Heater D Control Circuit Performance

Reductant heater D does not warm in time.

Is it safe to drive with P20C6?

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

Common causes

  • Most likelyPartial winding fault

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
Medium
DIY friendly
Best left to a mechanic
Typical labour
0.7–3 h
Emissions test
Likely to fail
Parts involved
Reductant Line Heater D

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