Cylinder 8 Deactivation/Intake Valve Control Circuit Open
Code P3457 indicates an open circuit in the cylinder 8 deactivation/intake valve control solenoid circuit. This solenoid is part of the Active Fuel Management (AFM) or Dynamic Fuel Management (DFM) system, which deactivates cylinders to improve fuel economy. 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 inactive improperly, leading to performance issues and potential engine damage.
01. Most Common Causes
- Faulty cylinder 8 deactivation/intake valve control solenoid
- Open or shorted wiring in the solenoid circuit
- Poor electrical connection at the solenoid connector
- Failed engine control module (ECM)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Rough idle or misfire on cylinder 8
- Reduced fuel economy
- Engine hesitation or loss of power
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm code P3457 and check for related codes.
Step 2: Inspect the wiring and connector for cylinder 8 deactivation solenoid for damage, corrosion, or loose pins.
Step 3: Measure resistance of the solenoid; compare to manufacturer specs (typically 20-30 ohms).
Step 4: Check for voltage and ground at the solenoid connector with the engine running.
Step 5: If wiring and solenoid are good, test the ECM output or replace the ECM.
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 8 to malfunction, leading to misfires, reduced performance, and potential catalytic converter damage.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, but can be higher if the ECM needs replacement.