Cylinder 2 Deactivation/Intake Valve Control Circuit High
The P3412 code indicates that the powertrain control module (PCM) has detected a high voltage condition in the circuit that controls the cylinder deactivation or intake valve control for cylinder 2. This system is used in engines with Active Fuel Management (AFM) or Variable Valve Timing (VVT) to improve fuel economy. A high voltage signal suggests a short to power, a faulty actuator, or a wiring issue. This can cause the cylinder to remain active when it should be deactivated, or vice versa, leading to performance problems.
1. Most Common Causes
- Faulty cylinder deactivation solenoid on cylinder 2
- Short to voltage in the wiring harness
- Corroded or damaged connector
- Failed PCM (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Rough idle or misfire
- Reduced fuel economy
- Engine hesitation or loss of power
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all codes and freeze frame data.
Step 2: Visually inspect the wiring and connector for cylinder 2 deactivation solenoid for damage, corrosion, or shorts.
Step 3: Test the solenoid resistance with a multimeter; compare to manufacturer specs.
Step 4: Check for voltage at the solenoid connector with key on; should be battery voltage or specific signal.
Step 5: If wiring and solenoid are good, test the PCM output or replace the PCM.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can cause engine misfire, reduced performance, and potential damage to the catalytic converter.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and simple repairs like wiring or connector fixes. Replacing a solenoid or PCM can cost more.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.