Powertrain
Definition only
Lights the check engine lamp
P239D: Diesel Intake Air Flow B Control System Low Air Flow Detected
Standardized SAE J2012 code · P23xx — Ignition system and misfire
What does P239D mean?
Same as P239C with the airflow below the threshold when the valve is commanded open - valve does not open fully or the path is restricted.
The code tells you which monitor failed, not which part is broken. Test before replacing parts.
Common causes
- High Valve does not open fully
Likelihood is a general estimate across vehicles; your make and model may differ.
Add your car to see reports of P239D on the same make and model first.
P239D in the community
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