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Old 02-05-2016, 01:00 PM   #1
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Default Testing GM MAF sensor off the vehicle

Is it possible to test a GM MAF sensor that is not connected to a vehicle?

I have one of the 3-wire MAF sensors from a 1996 Monte Carlo 3.1 L and it has a pin for a 12V (+), Ground (-), and Signal (F). I connected the 12V and Ground pins to a 12 volt battery. This sensor is supposed to output a hertz value; however, the multimeter only reads 0 Hz when it is connected between the signal and ground pins. When I switch the multimeter to read resistance, then the resistance value (ohms) outputs a signal that is proportional to the amount of air passing through the sensor.

It makes me wonder if the signal wire has to be connected to the electronic control module where other stuff happens to make the hertz reading.

Thank you. I look forward to hearing your responses.
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Old 02-05-2016, 04:57 PM   #2
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You need diagnostic equipment that can read hertz. Bench testing it will only tell you that its working. Not accurately.
It needs to be installed in the vehicle and a diagnostic scanner connected to the car that can scan live data will work better. Watching the live data knowing what to look for will tell you if its working accurately.
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Old 02-05-2016, 06:41 PM   #3
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It changes in hertz depending on how much air is flowing over the thermistor, no air flow would mean no change in hertz. The thermistor is heated and measured, air flows over it and readings change depending on the amount of air flowing over it.
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