OBD-II code · Powertrain (generic, extended)

P202F Reductant/Regeneration Supply Control Circuit Range/Performance

The control line that gates the DEF supply pump or the regeneration heating circuit does not respond as commanded — duty cycle, current draw, or response time off-spec.

Is it safe to drive with P202F?

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

Common causes

  • Most likelySupply relay aged or pitted contacts
  • PossibleSupply pump motor brushes worn
  • 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
Medium
DIY friendly
Best left to a mechanic
Typical labour
1–3 h
Emissions test
Likely to fail
Parts involved
Reductant Supply Pump, Reductant Supply Relay

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