Cylinder 3 Deactivation/Intake Valve Control Circuit Low
Diagnostic trouble code P3419 indicates that the powertrain control module (PCM) has detected a low voltage condition in the control circuit for the cylinder 3 intake valve deactivation solenoid. This typically means the circuit is shorted to ground or has excessive resistance, preventing the cylinder deactivation system from operating correctly.
While the vehicle can usually still be driven, the cylinder deactivation system will be disabled, leading to reduced fuel economy and potential drivability issues. It should be diagnosed and repaired soon to prevent further engine management complications.
Common symptoms
- Illuminated Check Engine Light
- Decreased fuel efficiency
- Engine misfires or runs rough
- Lack of engine power
- Cylinder deactivation system disabled
Likely causes
- Faulty cylinder 3 deactivation solenoid/actuator
- Wiring harness damage (short to ground or open circuit) in the cylinder 3 deactivation circuit
- Poor electrical connection at the cylinder 3 deactivation solenoid connector
- Low engine oil pressure or incorrect oil viscosity affecting actuator operation
- Restricted oil passages leading to the deactivation solenoid
- Faulty Powertrain Control Module (PCM) (rare)
What to check before replacing parts
Check engine oil level and condition.
Look for: Ensure the oil is at the correct level, is not excessively dirty, and is the correct viscosity, as cylinder deactivation systems rely heavily on proper oil pressure.
Visually inspect the wiring and connector for the cylinder 3 deactivation solenoid.
Look for: Look for frayed wires, melted insulation, corrosion, or loose pins that could cause a short to ground or high resistance.
Measure the resistance of the cylinder 3 deactivation solenoid using a digital multimeter.
Look for: Compare the resistance reading to the manufacturer's specifications; an out-of-spec reading indicates a faulty solenoid.
Check for voltage and ground at the solenoid connector with the key on, engine off (or commanded via scan tool).
Look for: Verify that the PCM is supplying the correct control voltage and ground; lack of voltage or constant ground indicates a wiring or PCM issue.
Perform an oil pressure test using a mechanical gauge.
Look for: Ensure engine oil pressure meets manufacturer specifications, as low pressure can prevent the deactivation solenoids from functioning properly.
This page explains the generic P3419 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.