Cylinder 8 Deactivation/Intake Valve Control Circuit/Open
Code P3457 indicates a problem in the cylinder deactivation system for cylinder 8, specifically an open circuit in the intake valve control solenoid or its wiring. This system, often found in V8 engines with Active Fuel Management (AFM) or similar technology, deactivates cylinders to improve fuel economy. An open circuit means the solenoid cannot be energized, preventing cylinder deactivation and potentially causing drivability issues.
1. 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
- Engine control module (ECM) failure (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced fuel economy
- Rough idle or misfire on cylinder 8
- Possible loss of power or hesitation
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the wiring and connector for cylinder 8 deactivation solenoid for damage, corrosion, or loose pins.
Step 3: Use a multimeter to check resistance of the solenoid; compare to specifications (typically 20-30 ohms).
Step 4: Check for voltage at the solenoid connector with the engine running; should see 12V on one pin.
Step 5: If wiring and solenoid are good, test the ECM output by commanding the solenoid on/off with a scan tool.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe for short distances, but the vehicle may experience reduced fuel economy and performance. Prolonged driving could lead to catalytic converter damage if misfiring occurs.
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 are usually $30-$80.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.