OBD-II code · Powertrain (generic, extended)
P2C91 Crankcase Ventilation System - Hose B Disconnected
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.
Is it safe to drive with P2C91?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyHose disconnected at fitting
- PossibleHose split or perforated
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.2–1 h
- Emissions test
- Likely to fail
- Parts involved
- Crankcase Vent Hose B, Crankcase Pressure Sensor, Intake Manifold
Related codes
- P2C90Crankcase Ventilation System - Hose A Disconnected
- P2C8EDC/DC Converter Temperature Sensor D Circuit Low
- P2C8FDC/DC Converter Temperature Sensor D Circuit High
- P2C92Hybrid/EV Battery Contactor Control Supply Circuit/Open
- P2C93Hybrid/EV Battery Contactor Control Supply Circuit Range/Performance
- P2C94Hybrid/EV Battery Contactor Control Supply Circuit/Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.