Cylinder 1 Deactivation/Intake Valve Control Performance
Diagnostic trouble code P3402 indicates that the powertrain control module (PCM) has detected a performance issue with the cylinder 1 deactivation or intake valve control circuit. The PCM sets this code when the measured values from the cylinder 1 intake valve control solenoid do not match the expected parameters during the cylinder deactivation process.
While the vehicle can usually still be driven, a failure in the cylinder deactivation system can lead to poor engine performance, reduced fuel economy, and potential internal engine wear if left unaddressed. It should be diagnosed and repaired soon to prevent further issues.
Common symptoms
- Illuminated Check Engine Light
- Engine misfires or runs rough
- Decreased fuel efficiency
- Lack of engine power or hesitation
- Vibration or shuddering during driving
Likely causes
- Low engine oil level or low oil pressure
- Dirty or degraded engine oil
- Faulty cylinder 1 deactivation solenoid / intake valve control solenoid
- Wiring or connector issues in the cylinder 1 deactivation circuit
- Restricted oil passages in the engine
- Faulty Powertrain Control Module (PCM)
What to check before replacing parts
Check the engine oil level and condition.
Look for: Ensure the oil is at the correct level on the dipstick and is 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: Compare the mechanical gauge reading to the manufacturer's specifications. Low oil pressure can prevent the deactivation solenoids from operating correctly.
Inspect the wiring and connectors for the cylinder 1 deactivation solenoid.
Look for: Look for frayed wires, corroded pins, melted insulation, or loose connections that could cause high resistance or an open circuit.
Test the resistance of the cylinder 1 deactivation solenoid.
Look for: Use a multimeter to measure the internal resistance of the solenoid. If the resistance is out of the manufacturer's specified range, the solenoid is faulty.
Command the cylinder 1 deactivation solenoid using a bi-directional scan tool.
Look for: Listen for an audible click from the solenoid and monitor the scan tool data to see if the PCM recognizes the state change. If it does not actuate, the solenoid or its control circuit is defective.
This page explains the generic P3402 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.
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