OBD-II code · Powertrain (generic)

P04E4 Crankcase Ventilation Hose Connection Sensor Circuit Intermittent or Erratic

Same as P04E1 with intermittent or erratic signal. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.

Is it safe to drive with P04E4?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyIntermittent contact at connector
  • Less likelyConnector with intermittent contact under vibration
  • Less likelyHarness routed against vibrating component

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, Pcv Hose Wiring

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.