Cylinder 1 Exhaust Valve Control Performance
The Powertrain Control Module (PCM) detected an improper operation or performance issue with the exhaust valve control mechanism for cylinder 1 during cylinder deactivation. This code is set when the engine computer observes that the exhaust valve for cylinder 1 is not transitioning correctly between active and deactivated modes based on expected manifold pressure or mass airflow readings.
While the vehicle can usually still be driven, the cylinder deactivation system will be disabled, leading to reduced fuel economy. Prolonged driving with valve control issues could potentially lead to internal engine wear or misfires, so it should be diagnosed soon.
Common symptoms
- Illuminated Check Engine Light
- Decreased fuel efficiency
- Engine misfires or rough idle
- Hesitation during acceleration
- Cylinder deactivation system disabled (stays in full cylinder mode)
Likely causes
- Low engine oil level or dirty engine oil
- Faulty cylinder deactivation solenoid for cylinder 1
- Defective cylinder deactivation valve lifter for cylinder 1
- Restricted oil passages in the engine block or valve control solenoid assembly
- Wiring or connector issues in the cylinder 1 exhaust valve control circuit
- Faulty Powertrain Control Module (PCM)
What to check before replacing parts
Check the engine oil level and condition.
Look for: Low oil levels or excessively dirty, sludged oil, which prevents proper hydraulic operation of the cylinder deactivation lifters.
Inspect the wiring and connectors for the cylinder 1 deactivation solenoid.
Look for: Chafed wires, corrosion, or loose connections that would cause an open or short circuit in the control system.
Test the cylinder 1 exhaust valve control solenoid operation using a bidirectional scan tool.
Look for: The solenoid failing to click or actuate when commanded by the scan tool, indicating a mechanically stuck or failed solenoid.
Measure the resistance of the cylinder 1 exhaust valve control solenoid with a digital multimeter.
Look for: Resistance values outside the manufacturer's specified range, confirming an internal electrical fault in the solenoid.
Perform an engine oil pressure test using a mechanical gauge.
Look for: Oil pressure below the minimum specification required to operate the cylinder deactivation lifters properly.
This page explains the generic P3406 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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