The Mass Airflow (MAF) sensor monitors the amount of air being drawn into the engine. Electric current from the PCM heats a wire inside of the MAF sensor. As air flows through the sensor, the temperature of the heated wire decreases. The PCM supplies more current to the sensor to maintain the temperature of the wire as air flow increases. The PCM monitors the current change, and increases the fuel injection output in proportion to the increased airflow.
Removal & Installation
- Disconnect the negative battery cable.
- Disconnect the MAF sensor electrical connector.
- Remove the air cleaner-to-intake manifold hose from the MAF sensor.
- Release the four spring clips from the air cleaner lid and remove the lid and MAF sensor assembly from the vehicle.
- Remove the four MAF sensor nuts and remove the sensor from the air cleaner lid.
The installation is the reverse of removal. Tighten the MAF sensor nuts to 71-88 inch lbs. (8-10 Nm).
- Run the engine until it reaches normal operating temperature.
- Turn the engine OFF .
- Using a voltmeter set to the DC range, connect the negative lead of a voltmeter lead to the negative battery terminal.
- With the MAF sensor electrical connector still connected, insert the positive lead probe into the back of the white and blue wire terminal of the connector.
- With the ignition switch on and the engine OFF , observe the voltmeter reading. The reading should be less than 1 volt.
- Start the engine and observe the voltmeter reading. The reading should be 1.0-1.7 volts.
- Speed the engine up to approximately 2,500 rpm. The voltmeter reading should rise to 1.9-2.3 volts.
- Allow the engine to return to idle.
- Observe the voltmeter reading while evenly revving the engine up to 4,000 rpm. The reading should rise smoothly to approximately 4.0 volts.
If the voltages are not within specifications, the sensor may be faulty.