Powertrain
Definition only
Lights the check engine lamp
P2ACE: Reductant Temperature Sensor B Circuit Low
Standardized SAE J2012 code · P2Axx codes
What does P2ACE mean?
Voltage on the reductant temperature B sensor signal line is below the expected window. Wire shorted to ground or sensor short.
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 Signal wire shorted to ground
- Medium Internal sensor short
- Low Connector pins corroded - high contact resistance
Likelihood is a general estimate across vehicles; your make and model may differ.
Add your car to see reports of P2ACE on the same make and model first.
P2ACE in the community
Ask about P2ACENo one has posted about P2ACE yet
Share your vehicle, the tool you used and what you tested — the first thread helps everyone who searches for this code.
Describe your P2ACE problem