P2391
Diesel Intake Air Flow B Control Performance
Same as P2390 with the actuator electrically intact yet not delivering the commanded position - sticky valve, broken linkage, or position offset.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Valve stuck due to sootCommon
Parts involved
- Diesel Intake Air Flow B
P2391 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.