Cylinder Deactivation Hydraulic Circuit Bank 1 Open
The engine control module has detected an open hydraulic circuit in the cylinder deactivation system on bank 1. The system uses pressurized engine oil routed through dedicated lifters and oil control valves to collapse valves; an open circuit indicates loss of oil flow or a failed pressure switch.
Affected components
- Oil control valve
- Oil pressure switch
- Lifter
- Engine oil passage
Common causes
- High likelihood: Oil pressure switch failed
- Medium likelihood: Oil passage blocked or sludge buildup
- Medium likelihood: Oil control valve stuck
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.