Cylinder 4 Deactivation/Intake Valve Control Circuit Open
Code P3425 indicates an open circuit in the cylinder 4 deactivation/intake valve control solenoid circuit. This solenoid is part of the cylinder deactivation system (e.g., Active Fuel Management or Variable Cylinder Management) that deactivates intake valves to shut down cylinders under light load. An open circuit means there is a break in the electrical path, preventing the solenoid from operating. This can cause the cylinder to remain active or fail to deactivate properly, leading to performance issues and potential engine damage.
01. Most Common Causes
- Faulty cylinder 4 deactivation/intake valve control solenoid
- Open or shorted wiring in the solenoid circuit
- Corroded or damaged connector at the solenoid
- Failed engine control module (ECM) - rare
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or performance
- Rough idle or misfire on cylinder 4
- Decreased fuel economy
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data. Clear codes and test drive to see if P3425 returns.
Step 2: Visually inspect the wiring and connector for cylinder 4 deactivation solenoid for damage, corrosion, or loose connections.
Step 3: Use a multimeter to check resistance of the solenoid (typically 10-30 ohms). If open or shorted, replace solenoid.
Step 4: Check for voltage at the solenoid connector with key on engine off. Should see battery voltage on one pin. If not, trace circuit back to ECM.
Step 5: If wiring and solenoid are good, suspect ECM failure. Perform ECM tests or consult a professional.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Driving with an open circuit can cause cylinder deactivation to malfunction, leading to misfires, reduced fuel economy, and potential catalytic converter damage. Have it diagnosed promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, depending on whether the solenoid or wiring needs replacement. Parts cost around $30-$80, labor $50-$100.