Cylinder 3 Deactivation/Intake Valve Control Performance
Diagnostic trouble code P3418 indicates a performance issue with the cylinder 3 deactivation or intake valve control circuit. The engine control module (ECM) sets this code when it detects that the intake valve for cylinder 3 is not operating as commanded during the cylinder deactivation process.
While the vehicle can usually still be driven, this code should be addressed soon to prevent potential engine damage and restore proper performance and fuel economy.
Common symptoms
- Illuminated Check Engine Light
- Engine misfires or runs rough
- Decreased fuel efficiency
- Lack of engine power or hesitation
- Vibration from the engine compartment
Likely causes
- Low engine oil level or poor oil pressure
- Faulty cylinder 3 deactivation solenoid/actuator
- Clogged oil passages restricting flow to the lifters
- Wiring or connector issues in the cylinder 3 deactivation circuit
- Mechanical failure of the cylinder 3 intake valve lifter
- Faulty Engine Control Module (ECM)
What to check before replacing parts
Check the engine oil level and condition.
Look for: Ensure the oil is at the correct level and not excessively dirty or sludged, as cylinder deactivation systems rely heavily on proper oil pressure and clean oil.
Test the engine oil pressure using a mechanical gauge.
Look for: Verify that the oil pressure meets the manufacturer's specifications at idle and under load, as low pressure can prevent the deactivation solenoids from operating correctly.
Inspect the wiring and connectors for the cylinder 3 deactivation solenoid.
Look for: Look for frayed wires, corrosion, or loose connections that could cause an open or short circuit in the control system.
Test the cylinder 3 deactivation solenoid electrically.
Look for: Measure the resistance of the solenoid with a multimeter and compare it to factory specifications; an out-of-range reading indicates a faulty solenoid.
Command the cylinder 3 deactivation solenoid using a bi-directional scan tool.
Look for: Listen for a click from the solenoid and monitor engine RPM/smoothness to see if the mechanical components respond to the electronic command.
This page explains the generic P3418 definition and is general reference information, not a diagnosis for your specific vehicle. Actual causes, severity, and repairs vary by make, model, engine, and mileage — always confirm with a scan tool and a qualified technician before replacing parts.
Gear guide: Best OBD2 ScannersRead this code yourself next time — from $20 Bluetooth dongles to bidirectional scan tools.Rather have a pro handle it? Find a vetted local mechanic.