Powertrain Definition only Lights the check engine lamp

P202D: Reductant Leakage

Standardized SAE J2012 code · P20xx — Fuel & air metering and auxiliary emission controls

What does P202D mean?

A leak has been detected in the DEF (urea) supply system — usually by a pressure-decay test after pump shutdown, or by visible crystallisation around fittings.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

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)

Common causes

  • High Cracked DEF line or fitting
  • Medium Pump seal leaking
  • Medium Injector mounting seal leaking

Likelihood is a general estimate across vehicles; your make and model may differ.

Add your car to see reports of P202D on the same make and model first.

P202D in the community

Ask about P202D

No one has posted about P202D yet

Share your vehicle, the tool you used and what you tested — the first thread helps everyone who searches for this code.

Describe your P202D problem