What does it mean?
P3428 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Cylinder 4 Deactivation/Intake Valve Control Circuit High . This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms
- MIL (check engine lamp) on and the deactivation feature disabled
- Fuel consumption noticeably higher on steady cruising
- Rough idle and vibration if the valve is stuck in one position
- Ticking or light knocking from the cylinder head
- Cylinder 4 misfire under light load
- Flat throttle response and occasional hesitation
Likely causes
- Control wire shorted to battery voltage where it runs beside a powered feed
- Open or high-resistance ground return leaving the output sitting at supply voltage
- Open coil inside the cylinder 4 deactivation solenoid so nothing loads the circuit
- Corroded or oil-contaminated terminals in the solenoid connector
- Moisture entering a connector and bridging a power pin to the control pin
- Failed PCM (powertrain control module) output driver, considered last
How to fix it
- Save the freeze frame and try to reproduce the fault while commanding the output with a scan tool
- Inspect the solenoid connector for oil, corrosion, spread terminals and melted plastic
- Back-probe the control wire with the key on and compare with a healthy cylinder on the same bank
- Disconnect the solenoid and module, then test the control wire for a short to any power feed
- Measure the coil resistance; an open coil produces a high circuit reading with no harness fault
- Verify the ground return and terminal tension in the connector
- Repair the wiring or replace the solenoid, then confirm normal operation with commanded switching and a road test