Cylinder 4 Deactivation/Intake Valve Control Circuit Low
The P3427 code indicates a low voltage condition in the cylinder 4 deactivation/intake valve control circuit. This circuit is part of the cylinder deactivation system (e.g., Active Fuel Management or Variable Cylinder Management) that deactivates intake valves to improve fuel economy. A low voltage reading suggests a short to ground, open circuit, or faulty component in the solenoid or wiring. This can prevent proper valve operation, leading to misfires, reduced power, and increased emissions.
01. Most Common Causes
- Faulty cylinder deactivation solenoid
- Short to ground in wiring or connector
- Open circuit in the control circuit
- Engine control module (ECM) failure
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine misfire or rough idle
- Reduced fuel economy
- Loss of power or hesitation
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect wiring and connector for damage, corrosion, or loose pins.
Step 3: Test the solenoid resistance with a multimeter (compare to specs).
Step 4: Check for voltage and ground at the solenoid connector with key on.
Step 5: If wiring and solenoid are good, test ECM output or replace ECM.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Driving with a cylinder deactivation circuit fault can cause misfires, catalytic converter damage, and reduced engine performance. Have it diagnosed promptly.
How much does it cost to fix?▼
Typical repair costs range from $50 to $150 for parts and labor, depending on whether it's a wiring repair or solenoid replacement. ECM replacement would be more expensive.