How to Test a 1995 Mazda Miata Mass Air Flow Sensor
The 1995 Mazda Miata mass air flow sensor measures the amount of air flow into the engine. The air passes a thin wire in the sensor, and the temperature of the air changes the voltage going through the wire. The sensor then sends a signal, based on the voltage in the wire, to the computer, so that the computer can determine how much fuel is needed for the appropriate air to fuel mixture. The mass air flow sensor is located in the air intake duct on the Miata.
Other People Are Reading
Instructions
-
DC Voltage Test
-
1
Look at the five wires going into the connector. The wire on the left is the electronic control module, or ECM, ground wire. The second wire is the ground wire. The third wire is the intake air temperature wire. The fourth wire is the mass air flow signal wire, and the fifth wire is the ignition wire.
-
2
Stick the needle into the fourth wire -- the mass air flow signal wire. Attach the voltmeter's red lead to the MAF signal wire and the black lead to a good ground. Turn the key on, but leave the engine off. The voltage should be 0.6 volts. '
-
-
3
Start the vehicle and allow it to warm up. The voltage should be about 1.3 volts. Slowing bring the rpm up to 2,500 while watching the voltmeter. The voltage should go up to about 1.6 volts. While the voltage is rising it should rise smoothly with no drop outs -- it should never go up then go down as long as the increase in rpm is smooth. Turn the vehicle off.
Out of Range or No Signal Test
-
4
Stick the needle in the ECM ground wire, if the voltage in the previous section was out of range, or if you got no signal when testing. Attach the red lead on the voltmeter to the needle and the black lead to a good ground.
-
5
Turn the key on. The voltage should read below 100mV. If not, replace the MAF sensor. If the voltage is below 100mV, stick the needle into the ignition wire. Attach the red voltmeter lead to the needle. Leave the black lead on a good ground.
-
6
Turn the key on, but leave the engine off. If the voltage is not about 12 volts, replace the MAF sensor.
-
1
