Cylinder 3 Exhaust Valve Control Circuit High
Diagnostic Trouble Code P3424 indicates that the Powertrain Control Module (PCM) has detected a high voltage condition in the control circuit for the cylinder 3 exhaust valve deactivation mechanism. This typically means the circuit is shorted to power or has high resistance, preventing the cylinder deactivation system from operating correctly on cylinder 3.
While the vehicle can usually still be driven, the cylinder deactivation system will be disabled, leading to reduced fuel economy. It should be diagnosed soon to prevent potential drivability issues or further electrical damage.
Common symptoms
- Illuminated Check Engine Light
- Decreased fuel efficiency
- Engine misfire or rough idle
- Poor engine performance or hesitation
- Cylinder deactivation system disabled
Likely causes
- Faulty cylinder 3 exhaust valve control solenoid
- Short to power in the cylinder 3 exhaust valve control circuit
- Corroded, damaged, or loose electrical connector at the solenoid
- Open circuit or high resistance in the wiring harness
- Low engine oil pressure or restricted oil passages
- Faulty Powertrain Control Module (PCM) (rare)
What to check before replacing parts
Check the engine oil level and condition.
Look for: Low oil level or extremely dirty oil can prevent the hydraulic cylinder deactivation lifters/solenoids from operating correctly.
Visually inspect the wiring and connector for the cylinder 3 exhaust valve control solenoid.
Look for: Look for frayed wires, melted insulation, or a corroded/loose connector that could cause a short to power or high resistance.
Measure the resistance of the cylinder 3 exhaust valve control solenoid using a multimeter.
Look for: Compare the resistance reading to the manufacturer's specification; an out-of-spec reading indicates a faulty solenoid.
Test the control circuit for a short to power.
Look for: With the solenoid disconnected and the key ON, check for unexpected battery voltage on the control wire, which indicates a short to power in the harness.
Check engine oil pressure using a mechanical gauge.
Look for: Oil pressure below the manufacturer's minimum specification can prevent the deactivation solenoids from functioning properly.
This page explains the generic P3424 definition and is general reference information, not a diagnosis for your specific vehicle. Actual causes, severity, and repairs vary by make, model, engine, and mileage — always confirm with a scan tool and a qualified technician before replacing parts.
Gear guide: Best OBD2 ScannersRead this code yourself next time — from $20 Bluetooth dongles to bidirectional scan tools.Rather have a pro handle it? Find a vetted local mechanic.