P04E2Crankcase Ventilation Hose Connection Sensor Circuit Low
- 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). P04E2 means the sensor signal is too low: GM's LSY sets it at 4.3 % of 5 V or less (about 0.22 V) in 1280 of 1600 samples, MIL after two trips. With this ratiometric sensor an open signal line also reads low, as does a missing 5 V reference. 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 open or shorted to ground
- Possible5 V reference open or shorted (often shared with other sensors)
- PossibleConnector not latched or corroded
- PossibleSensor faulty
- 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.