Powertrain
Definition only
Lights the check engine lamp
P2C91: Crankcase Ventilation System - Hose B Disconnected
Standardized SAE J2012 code · P2Cxx codes
What does P2C91 mean?
The ECM detects that crankcase ventilation hose B is disconnected based on pressure or vacuum signals. Unmetered air ingress and oil mist escape are possible.
The code tells you which monitor failed, not which part is broken. Test before replacing parts.
Common causes
- High Hose disconnected at fitting
- Medium Hose split or perforated
Likelihood is a general estimate across vehicles; your make and model may differ.
Add your car to see reports of P2C91 on the same make and model first.
P2C91 in the community
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