P04E3Crankcase Ventilation Hose Connection Sensor Circuit High
- 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 ventilation (PCV) system routes blow-by gas from the crankcase into the intake; CARB requires a disconnection between crankcase and intake to be detected. GM's 2.0-litre LSY has a pressure sensor in the PCV hose: with the hose connected it must see a pressure drop that grows with air flow, plus pressure pulses from the pistons. Ford reports the same sensor type as crankcase pressure sensor A (P051A ff). P04E3 means the sensor signal is too high: GM's LSY sets it at 95.5 % of 5 V or more (about 4.78 V) in 1280 of 1600 samples, MIL after two trips. Typical is a signal line shorted to 5 V or battery voltage; an open sensor ground can also pull the signal up. The disconnection check P04DB is then suspended.
- What you may notice
- Check engine light on
- Disconnection check P04DB does not run
- Usually no change in driving
- Likely causes
- LikelySignal line shorted to 5 V or battery voltage
- PossibleSensor ground open
- PossibleSensor faulty
- RareCorroded or wet connector
- 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: €50 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.