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Home >   How To >   How to Repair Mass Air Flow Sensor >   Mass Air Flow Sensor Diagnostics

Mass Air Flow Sensor Diagnostics

Mass Air Flow Sensor    




The engine of a car is equipped with a mass air flow sensor that measures the volume and density of the air entering the engine. In this way, the vehicle's Engine Control Unit (ECU) can calculate how much fuel is needed to maintain the correct air-fuel mixture.




The breakdown shown here is of the mass air flow sensor housing and it shows the individual parts that make up the full unit. The unit is made up of an air temperature sensor, sample tube, metal foil sensing element, electronic module and then the top cover and the flow tube. All of these elements work together to properly sense the air flow.


Mass Air Breakdown    




The mass air flow sensor works by reading the amount of air passing the aperture at a given time. This is sent to the vehicle's computer via electrical pulses which can be interpreted. This will allow the computer to adjust the fuel added to the motor to create the correct air-fuel ratio. The mass air flow sensor not only reads the amount of air flow but reads the temperature of the air, as well. The air temperature is just as vital of a factor as the amount of air brought into the engine. The mass air flow sensor will have a screen to protect the unit from debris. This is not to stop dust or dirt but is intended to protect the engine from any large debris that could enter the system.


Mass Air Flow Working    


Cause of a MAF sensor failure:


In some situations, mass airflow sensor begins to fail due to contamination caused due to oil or dirt entering the sensor. In both cases, if the mass airflow sensor becomes dirty, the fix is to clean it or replace it.


Symptoms of a faulty MAF sensor:


When your engine runs lean, a failure of the MAF sensor can be a likely cause. If your engine is having trouble running or idles erratically, or if the throttle decreases at highway speed, it is a possible indicator of a defective MAF sensor. A faulty MAF sensor will also illuminate the “Check Engine” light on your dashboard.


Is your MAF sensor at fault? Replace it now!


If you notice that your engine is running below its efficiency, make sure that you check your car's computer to ascertain if the MAF sensor is the cause of failure. If it is the cause of your engine's problems, you should replace it or clean it at the earliest to prevent your engine from sustaining further damage.


For MAF sensor problems you can analyze the computer yourself by attaching a digital scanner on the vehicle's housing circuit and scan for any fault codes. You can find scanners at auto shops and even if some of them work differently, they all have the same function in the end.


Check the error codes generated by the scanner against those listed in your scanner's instruction manual to narrow down the cause of your engine's problem. If the generated codes match that of the MAF sensor, head over to your service center and replace the sensor. The MAF sensor being repairable is very rare.


The mass airflow sensor can be removed from the car's filter housing. Spray the sensor's wires with electrical cleaner ONLY and let the MAF sensor air dry before you reinstall it. Start the car and if the check engine light is off, the problem has been resolved.


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Check out Buy Auto Parts' extensive range of mass air flow sensors that carry an industry-leading warranty at unbeatable prices! To place an order, just select the right year, make and model of your vehicle. You can get your mass air flow sensors delivered from the warehouse closest to your location at the earliest. We also stock Mass air flow sensor probes. Buy Auto Parts sells thoroughly-tested OEM replacement and aftermarket parts for every car make and model. We offer free shipping for orders over $50 in the continental United States. You can convey your difficulties to us through our toll-free number, or you can leave us an email at [email protected]. We have got automotive professionals to answer to your queries regarding any of our parts.


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