OBD-II code · Powertrain (generic)
P04E1 Crankcase Ventilation Hose Connection Sensor Circuit
A dedicated sensor monitors whether the PCV hose is fitted to its connector at the engine. The ECU detects a circuit fault on this sensor - cannot determine whether the hose is connected. Required by some emissions regulations to flag a disconnected PCV hose immediately.
Is it safe to drive with P04E1?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen in sensor circuit
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.4–1.2 h
- Emissions test
- Likely to fail
- Parts involved
- Pcv Hose Connection Sensor
Related codes
- P04DECold Start EGR A Flow Excessive Detected
- P04DFEVAP System Purge Control Valve A Performance Stuck Open
- P04E0EVAP System Purge Control Valve A Stuck Closed
- P04E2Crankcase Ventilation Hose Connection Sensor Circuit Low
- P04E3Crankcase Ventilation Hose Connection Sensor Circuit High
- P04E4Crankcase Ventilation Hose Connection Sensor Circuit Intermittent or Erratic
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.