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.
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.
Common causes
- high
PCV valve clogged or stuck
One of the most commonly reported causes for this code — check this first.
Typical part cost: $90-880
- medium
Oil separator clogged
A plausible cause — test and verify before replacing parts.
Typical part cost: $90-880
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does P04FC mean?
P04FC means "Crankcase Ventilation System Performance". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.
What are the most common causes of P04FC?
pcv valve clogged or stuck; oil separator clogged; excessive blow-by from worn piston rings — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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