P051ACrankcase Pressure Sensor A Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- The crankcase pressure sensor measures pressure in the crankcase ventilation (PCV) against atmosphere; Ford's EcoBoost engines use it for the disconnection check P04DB, which needs a sound sensor. P051A is the sensor's general circuit fault. Ford uses it only for the digital SENT sensor, when the module receives invalid messages or signal patterns (together with U060E for lost communication); analogue sensors report P051B–P051D instead. It is checked continuously with 5 s to fault.
- What you may notice
- Check engine light on
- Usually no change in driving
- Disconnection check P04DB suspended
- Likely causes
- LikelyConnector or supply, ground or SENT signal wire open or corroded
- PossibleSensor electronics faulty
- PossibleOil or moisture in the connector
- RareEngine module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €40 – €200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.