P04FB
Crankcase Ventilation Hose Connection Sensor Range or Performance
The sensor that monitors PCV hose connection reports a value within plausible range yet inconsistent with the engine model - signal does not switch when the hose is moved during diagnosis, or shows offset against actual hose state.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: easy
Common causes
Ordered by how often each turns out to be the cause.
- Sensor signal offsetCommon
Parts involved
- PCV Hose Connection Sensor
P04FB 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.