P2394
Diesel Intake Air Flow B Control Stuck Open
Diesel intake air flow valve B is mechanically stuck open - the ECU cannot close it for anti-shudder shutdown or EGR mixing assistance.
- 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 open due to soot or broken linkageCommon
- Carbon or debris buildup preventing free movementLess likely
- Component wear with age - mechanical playLess likely
Parts involved
- Diesel Intake Air Flow B
P2394 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.