WOMS
P code powertrain High severity

P035B Ignition Coil 'B' Primary/Secondary Circuit Malfunction

The OBD2 code P035B indicates a malfunction in the primary or secondary circuit of ignition coil 'B', which can affect the ignition system's performance and engine operation

Definition

The OBD2 code P035B indicates a malfunction in the primary or secondary circuit of ignition coil 'B', which can affect the ignition system's performance and engine operation

Common causes

  • Faulty ignition coil 'B'
  • Damaged wiring or connectors in the ignition circuit
  • Short circuit or open circuit in the ignition coil circuit
  • Faulty engine control module (ECM)
  • Poor ground connection
  • Corroded or damaged terminals
  • Faulty spark plugs or ignition components
  • Issues with the ignition control module (ICM)

Common misdiagnoses

  • Faulty ignition coil
  • Bad spark plugs
  • Ignition control module failure
  • Wiring issues or shorts
  • Engine control unit (ECU) problems
  • Fuel injector issues
  • Vacuum leaks
  • Crankshaft or camshaft position sensor failure
  • Timing belt or chain problems
  • Battery or charging system issues

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 if there are related issues

  2. 2. Visual Inspection

    Inspect the ignition coil and its wiring for any visible damage, such as frayed wires, corrosion, or loose connections

  3. 3. Check the connectors for signs of wear or damage

  4. 4. Test the Ignition Coil

    Swap the ignition coil with another cylinder (if applicable) to see if the code follows the coil. If it does, the coil may be faulty

  5. 5. Use a multimeter to test the resistance of the ignition coil. Compare the readings to the specifications in the vehicle’s service manual

  6. 6. Check the Power and Ground Supply

    Verify that the ignition coil is receiving the correct voltage. Use a multimeter to check for power at the coil connector

  7. 7. Check the ground connection for the ignition coil to ensure it is secure and functioning properly

  8. 8. Inspect the PCM (Powertrain Control Module)

    Ensure that the PCM is functioning correctly. A malfunctioning PCM can sometimes cause ignition coil issues

  9. 9. Check for any software updates or recalls related to the PCM

  10. 10. Examine the Wiring and Connectors

    Inspect the wiring harness for any signs of damage, shorts, or open circuits

  11. 11. Ensure that all connectors are clean and securely connected

  12. 12. Check for Vacuum Leaks

    Vacuum leaks can affect engine performance and may lead to ignition issues. Inspect hoses and gaskets for leaks

  13. 13. Test Related Components

    If applicable, check other components related to the ignition system, such as spark plugs and ignition control modules

  14. 14. Ensure that the spark plugs are in good condition and properly gapped

  15. 15. Clear the Codes and Test Drive

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

  16. 16. Consult a Professional

    If the issue persists after following these steps, it may be necessary to consult a professional mechanic for further diagnosis.Additional Notes: - Always refer to the vehicle’s service manual for specific testing procedures and specifications. - Safety precautions should be taken when working on the ignition system, as it involves high voltage. By following these troubleshooting steps, you should be able to identify the cause of the P035B code and take appropriate action to resolve the issue