Powertrain
Definition only
Lights the check engine lamp
P2D5A: Reductant Level Sensor A/B Correlation
Standardized SAE J2012 code · P2Dxx codes
What does P2D5A mean?
The signals of the reductant level sensors A and B do not correlate within the calibrated tolerance. One sensor drifts or installation offset between channels.
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 One sensor characteristic drifted
- Medium Harness incorrectly swapped between channels
Likelihood is a general estimate across vehicles; your make and model may differ.
Add your car to see reports of P2D5A on the same make and model first.
P2D5A in the community
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