The mass airflow (MAF) sensor is a device that measures the volume and density of air so that the electronic control module can calculate the proper mixture of fuel injected into the fuel injectors. It does this by converting the intake of air into a voltage signal that the electronic control module can measure. The MAF sensor is located directly in the path of incoming air, between the air cleaner and the throttle body. A malfunctioning MAF sensor can cause the engine to stall, misfire or have poor gas mileage.
Look in your owner's manual for your specific GM MAF sensor settings. If you do not have an owner's manual, call your local GM dealer to inquire about the MAF sensor specifications for your vehicle.
Open the hood of the car and locate the MAF sensor housed between the air cleaner and the throttle body. It is a plastic clip with cables coming out of both ends. Inspect the sensor to be sure it is tightly clipped together at both ends.
Gently press the clips in and pull apart to release their connection. Inspect the inside of the connectors for debris, or anything that could interfere with conducting a voltage signal.
Start the car and then insert the probe of a voltmeter into the MAF sensor output terminal port. Turn the voltmeter on and check whether the voltage remains at a steady state of 2 to 3 volts. Gently tap the MAF sensor while the car is running and while the probe is in the terminal port. If the voltage reading stays constant, the MAF sensor is fine. If the engine begins to knock or the sensor reading changes, the MAF sensor needs to be changed.
Press on the accelerator to change the rpm of the engine while taking a voltage reading. If the voltage of the MAF sensor changes more than the rpm increase, the MAF sensor will need to be changed. To check for heat-related issues, use a hairdryer and point the hot air toward the MAF sensor and its cable connectors. Any heat-related issues will cause the voltage reading to increase.
