WOMS
P code powertrain Medium severity

P0104 Mass or Volume Air Flow "A" Circuit Intermittent

The OBD2 code P0104 indicates that there is an intermittent issue with the mass or volume air flow sensor "A" circuit, which means the sensor is not consistently providing accurate readings to the engine control module

Definition

The OBD2 code P0104 indicates that there is an intermittent issue with the mass or volume air flow sensor "A" circuit, which means the sensor is not consistently providing accurate readings to the engine control module

Common causes

  • Faulty Mass Air Flow (MAF) sensor
  • Dirty or clogged MAF sensor
  • Air intake leaks
  • Damaged wiring or connectors in the MAF circuit
  • Faulty engine control module (ECM)
  • Vacuum leaks
  • Clogged air filter
  • Exhaust leaks
  • Intermittent electrical connections
  • Corroded connectors or terminals

Common misdiagnoses

  • Faulty Mass Air Flow (MAF) sensor
  • Vacuum leaks
  • Dirty or clogged air filter
  • Faulty engine control module (ECM)
  • Wiring issues or poor connections
  • Throttle body problems
  • Fuel delivery issues
  • Intake manifold leaks
  • Exhaust leaks
  • Faulty oxygen sensors

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 additional context for the issue

  2. 2. Inspect the MAF Sensor

  3. 3. Physical Inspection

    Check the MAF sensor for any signs of damage, dirt, or contamination. Ensure that the sensor is securely connected

  4. 4. Connector and Wiring

    Inspect the wiring and connector for any signs of wear, corrosion, or loose connections. Look for frayed wires or broken pins

  5. 5. Clean the MAF Sensor

    If the sensor appears dirty, use a MAF sensor cleaner to clean it. Avoid using other types of cleaners, as they can damage the sensor

  6. 6. Check for Vacuum Leaks

    Inspect the intake system for any vacuum leaks that could affect the air flow readings. Look for cracked hoses, loose clamps, or damaged intake components

  7. 7. Test the MAF Sensor

  8. 8. Use a multimeter to test the MAF sensor according to the manufacturer's specifications. Check the voltage and signal output while the engine is running

  9. 9. If available, use a scan tool to monitor the MAF sensor readings in real-time to see if they are within the expected range

  10. 10. Inspect the Air Filter

    A clogged or dirty air filter can restrict airflow and affect MAF sensor readings. Replace the air filter if necessary

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

    Ensure that the ECM is functioning properly. In rare cases, a faulty ECM can cause intermittent issues with the MAF sensor circuit

  12. 12. Look for Intermittent Issues

    Since the code indicates an intermittent problem, pay attention to the conditions under which the code is triggered. It may be temperature-related, vibration-related, or occur under specific driving conditions

  13. 13. Perform a Visual Inspection of the Intake System

    Check for any obstructions in the intake system that could affect airflow, such as foreign objects or collapsed hoses

  14. 14. Clear the Codes and Test Drive

    After performing the necessary repairs or adjustments, clear the trouble codes and take the vehicle for a test drive to see if the code reappears. 1

  15. 15. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the MAF sensor or the specific vehicle model, as manufacturers may have issued guidance on common issues. If the problem persists after following these steps, it may be necessary to consult a professional mechanic for further diagnosis and repair