OBD-II code · Powertrain (generic)
P04FC Crankcase Ventilation System Performance
A general performance fault of the crankcase ventilation system - PCV pressure or flow does not match the engine model. Possible causes are a clogged PCV valve, blocked separator, oil-filler cap with a damaged seal, or excessive blow-by from worn rings.
Is it safe to drive with P04FC?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyPCV valve clogged or stuck
- PossibleOil separator clogged
- Less likelyExcessive blow-by from worn piston rings
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.6–3 h
- Emissions test
- Likely to fail
- Parts involved
- Pcv Valve, Oil Separator, Oil Filler Cap
Related codes
- P04F9Catalyst Heater Circuit Intermittent Bank 2
- P04FAEGR A Control Temperature Too High
- P04FBCrankcase Ventilation Hose Connection Sensor Range or Performance
- P04FDEGR Actuator A Control Processor Performance
- P04FECatalyst Heater Circuit Performance Bank 1
- P04FFCatalyst Heater Circuit Performance Bank 2
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.