The MAF is measured by detection of heat transfer from a hot film probe because the change of the mass air flow rate causes change in the amount of heat being transferred from the hot film probe surface to the air flow. The air flow sensor generates a pulse so it repeatedly opens and closes between the voltage (5V) supplied from the PCM. This results in a change of the temperature of the hot film probe and in the change of resistance.
Removal & Installation
- Disconnect the negative battery cable.
- Disconnect the connector from the sensor.
- Remove the air cleaner and air intake assembly, as required.
- Remove the sensor from its mounting.
- Installation is the reverse of the removal procedure.
- Allow the engine coolant to reach 176-198 degrees F.
- Using a voltmeter check the sensor output voltage.
- Specification should be 0.5 volt at idle, 1.0 volt at 2000 rpm.
- If the measured value is not within specification, replace the sensor.