P2C90

Code

Generic P — Powertrain

Crankcase Ventilation System - Hose A Disconnected

Brand: Generic

Type: P — Powertrain

Views: UK: 24 EN: 118 RU: 36

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Page language: EN

Check Engine MIL illuminated
Rough idle or unstable idle speed
High or fluctuating crankcase pressure; oil leaks or seepage around hose connections
Increased oil consumption or oil in intake
Possible drivability issues: hesitation, stalling, or poor throttle response
Elevated fuel trims or lean condition codes on scan tool

Visual inspection of PCV/vent hoses and connections for disconnection, damage, or missing clamps
Wiggle hoses and fittings while engine is running to reproduce symptoms
Listen for hissing/air leak near hose A and associated connections
Use a scan tool to view fuel trim, MAP/vacuum and misfire counts
Perform a smoke test of intake/crankcase ventilation to find leaks
Check for oil stains or wetness around hose ends and fittings

Intake manifold vacuum: lower or fluctuating vacuum at idle
Short-term/long-term fuel trims: positive (lean) corrections may be observed, often >+10%
MAP sensor/pressure reading: may show lower-than-expected manifold pressure
Misfire counters: may show increased misfires under certain conditions
Crankcase pressure or vent flow (if equipped): abnormal high pressure or no controlled flow

Safety first: work with a cool engine when possible and secure vehicle on level surface.
Retrieve trouble code and freeze frame with a scan tool and note fuel trims, MAP/vacuum, RPM and load.
Perform a visual inspection of Hose A, its connections at the PCV valve and intake manifold, and nearby fittings for disconnection, cracks, splits or missing clamps.
If visual check is inconclusive, start the engine and listen for vacuum leak (hissing) at Hose A and related connections; spray a safe smoke/soapy solution cautiously to localize leak.
Use a smoke machine into the intake/crankcase ventilation system to identify leaks or disconnected hoses; watch for smoke exiting from hose A or other joints.
If Hose A is disconnected or damaged, reconnect with correct orientation and install a new OEM-appropriate hose and clamp or replace quick-connect fitting as required.
Inspect and, if necessary, replace the PCV valve or vent valve if it’s stuck or damaged and may have caused hose separation.
After repair, wipe area clean, clear trouble codes with scan tool and perform a road/idle test while monitoring fuel trims, MAP and misfire counters to confirm parameters return to normal.
If code returns or symptoms persist, inspect intake manifold gasket, other vacuum lines, and perform further diagnostics (pressure/vacuum checks, intake manifold inspection, component-specific tests).