WOMS
P code powertrain High severity

P3420 Cylinder 3 Deactivation/Intake Valve Control Circuit High

The OBD2 code P3420 indicates that there is a high voltage signal detected in the intake valve control circuit for cylinder 3, which is related to the cylinder deactivation system

Definition

The OBD2 code P3420 indicates that there is a high voltage signal detected in the intake valve control circuit for cylinder 3, which is related to the cylinder deactivation system

Common causes

  • Faulty intake valve control solenoid
  • Wiring issues or damaged connectors
  • Faulty engine control module (ECM)
  • Low engine oil level or poor oil quality
  • Blocked or restricted oil passages
  • Faulty camshaft or timing chain/belt
  • Vacuum leaks
  • Faulty cylinder deactivation system components

Common misdiagnoses

  • Faulty camshaft or timing issues
  • Ignition system problems
  • Fuel delivery issues
  • Vacuum leaks
  • Faulty engine control module (ECM)
  • Wiring or connector issues
  • Faulty intake valve actuator
  • Low oil pressure
  • Cylinder head problems
  • Exhaust system restrictions

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. This can provide more context and help identify related issues

  2. 2. Inspect Wiring and Connectors

    Visually inspect the wiring and connectors associated with the intake valve control for cylinder 3. Look for signs of damage, corrosion, or loose connections

  3. 3. Pay special attention to the wiring harness that runs to the intake valve actuator

  4. 4. Test the Intake Valve Actuator

    If accessible, test the intake valve actuator for cylinder 3. This may involve checking the resistance of the actuator coil and ensuring it operates correctly when commanded

  5. 5. If the actuator is faulty, it may need to be replaced

  6. 6. Check the Engine Control Module (ECM)

    Ensure that the ECM is functioning properly. Sometimes, a software update or reprogramming may be necessary

  7. 7. Check for any known issues or recalls related to the ECM for your specific vehicle model

  8. 8. Inspect the Cylinder Deactivation System

    Review the entire cylinder deactivation system for any mechanical issues. This includes checking the oil level and condition, as low oil pressure can affect the operation of the system

  9. 9. Ensure that the system is not stuck in the deactivated position due to carbon buildup or mechanical failure

  10. 10. Check for Vacuum Leaks

    Inspect for any vacuum leaks in the intake system that could affect the operation of the intake valves

  11. 11. Perform a Visual Inspection of the Engine

    Look for any signs of engine damage or wear that could affect cylinder operation, such as a blown head gasket or damaged valves

  12. 12. Clear Codes and Test Drive

    After performing any repairs or adjustments, clear the trouble codes and take the vehicle for a test drive to see if the code returns

  13. 13. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the P3420 code for your vehicle make and model. Manufacturers may have specific fixes or recommendations for this issue

  14. 14. Seek Professional Help

    If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who has experience with your vehicle's specific engine and systems. By following these troubleshooting steps, you can systematically identify and resolve the issue associated with the P3420 code