Proper functioning of you car's air intake temperature sensor can help you avoid costly repairs to your engine and other components. Sensors are simple to test at home to ensure they are working correctly.
Understand the purpose of the air intake temperature sensor. The sensor keeps tabs on the temperature of the air circulating through the exhaust system. It is located in the air cleaner housing or duct and helps the car's computer regulate the exhaust-gas recirculation.
Know when to test the sensor. The "check engine" or "service engine" light will come on as is your first indicator that something is wrong. At this point, it could be an actual problem or a malfunctioning sensor.
Remove the air intake temperature sensor after first removing the air intake housing. Let the engine cool before doing this, as you can be severely burned. Allow the sensor to cool before further testing. You will need a hair drier and ohmmeter for the testing portion of this process.
Test the MAT's resistance when it is cold, by holding the probe on the ohmmeter. Note what it registers. Then warm it up with the hair drier and test it again. Check your vehicle's repair or service manual for the acceptable ohm range. Reinstall the sensor if it is within range. If you are still having the same problem, reset your car's computer by disconnecting the negative battery charge for five minutes.