P202A: Reductant Tank Heater Control Circuit/Open
Standardized SAE J2012 code · P20xx — Fuel & air metering and auxiliary emission controls
What does P202A mean?
The DEF tank heater control circuit is open or has lost continuity — the PCM cannot drive the resistive heater that prevents the DEF (urea) tank from freezing in winter.
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 Heater element winding open
- Medium Open wire between PCM and heater
- Low Pin pushed back out of connector body
Likelihood is a general estimate across vehicles; your make and model may differ.
Add your car to see reports of P202A on the same make and model first.
P202A in the community
Ask about P202ANo one has posted about P202A yet
Share your vehicle, the tool you used and what you tested — the first thread helps everyone who searches for this code.
Describe your P202A problem