OBD-II code · Powertrain (generic)

P065D Reductant System Malfunction Lamp Control Circuit

A circuit fault on the AdBlue malfunction warning lamp output - regulatory in many regions to alert the driver of NOx aftertreatment problems.

Is it safe to drive with P065D?

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

Common causes

  • Most likelyOpen in lamp or wiring

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 h
Emissions test
Likely to fail
Parts involved
Reductant Warning Lamp

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