Genuine Toyota Avalon Mass Air Flow Sensor

Toyota Avalon Mass Air Flow Sensor Parts Questions & Answers

• Meter Sub-Assembly, INTA
  22204-0V010
  Q: How to remove and reinstall the Mass Airflow (MAF) sensor?

  A: The Mass Air Flow Sensor, technology that measures the amount of air entering the engine, is typically located on the air intake duct. Before starting, ensure that the ignition key is in the OFF position to prevent any injury or accidents. To remove it, first disconnect the electrical connector. Then, unscrew the retaining bolts. Remove the MAF sensor. To perform an installation, you can simply follow the exact opposite steps that were taken during the removal process.
• Meter Assy, Intake Air Flow
  22250-20020
  Q: What is the location and function of the Mass Airflow (MAF) sensor?

  A: The Mass Air Flow Sensor, located on the air intake duct, is a system circuit with a platinum hot wire, a thermistor, and a control circuit within a plastic housing. This setup detects changes in intake air temperature. When the throttle opens, more air cools the wire, causing the PCM to increase the current flow to maintain a constant temperature. The MAF sensor's output voltage signal varies with this current flow, and the PCM measures this, turning the injectors on and off accordingly. A problem in this circuit sets a diagnostic trouble code. To check the MAF sensor, first check for power to it, looking for 9-14 volts between terminal number 4 and the ground. If voltage is absent, check the circuit between the EFI main relay and the MAF sensor. Next, check the MAF sensor voltage signal to the PCM by back-probing the MAF sensor connector. If the indicated signal voltage is out of range, inspect the wiring harness for bad connections, open circuits, or damage. If these are fine, the MAF sensor might be faulty, but given its cost, consider having the circuit checked before replacing it. For removal, turn the ignition key to OFF, disconnect the electrical connector from the MAF sensor, and remove the air cleaner assembly, and the two sensor retaining bolts to remove the MAF sensor and gasket. Installation is the reverse of removal, with a new gasket or O-ring between the MAF sensor and the intake duct.