7 Common MAF Sensor Failures: Symptoms, Problems & Cleaning!
The Mass Air Mass Sensor (MAF) is a critical component in your car’s fuel injection system. It sits between the air filter and the intake manifold, carefully measuring the amount of air drawn into the engine to fuel combustion. On this occasion we will tell you everything about the common failures of the MAF sensor , and how to detect them.
This sensor is important because it sends the information to the engine control unit (ECU), which in turn supplies the correct amount of fuel to the engine. As the sensor collects different information about air density, temperature and other variables, it ensures that the engine is running at the most efficient level.
What is the function of the Mass Air Flow Sensor or MAF?
The air mass sensor is relatively simple. Contains two cables. One is hot and one is cold. The system measures how much power it takes for the cold wire to feel the heat from the hot wire; a value that is affected by the amount of air flowing between the two wires, thus adjusting the airflow in the motor accordingly .
Why is the MAF malfunctioning?
Over time, the sensor will degrade and become increasingly prone to failure. Because the part is constantly exposed to air, full of contaminants such as dirt and exhaust fumes from other vehicles on larger roads, it can become dirty, preventing it from functioning properly. Or, in the worst case, a power surge could fry the circuitry, making it unable to transmit information to the ECU.
Common MAF Sensor Symptoms and Failures
You should be aware of the following signs that could indicate that your engine’s mass air flow sensor is failing:
1- Engine light illuminates
By far the most common sign that you are having sensor trouble is the check engine light. However, it could flicker for a number of reasons, not all of which are related to airflow. Have the car error codes scanned. If the codes go from P0100 to P0104 this indicates that there is something wrong with the sensor. Damaged or faulty sensors will have codes P0171 or P0174.
2- Engine slowdown
Is your car running poorly? Which means you are struggling for power and perhaps stalling more could this mean you are getting too much air into the engine and not enough fuel? Too much air means that the combustion process is not working properly. The cause is usually dirt buildup on the sensor cables. Have a technician clean the wires, which should restore sensor function.
3- The engine does not start correctly
Do you have problems starting the car? If the engine cranks and the battery is fine, it could be due to a bad air-fuel mixture. Possibly because the ECU can’t measure the airflow going into the engine. Check first that it is not the spark plugs and then have a professional look at the sensor.
4- Engine drag
Do you have problems when you add an extra load to the car? This may be because the car needs more fuel. If the mass air flow sensor is playing, then the powertrain control module will not be able to determine the optimum air-fuel mixture, which in turn causes the engine to suffer and drag.
5- Acceleration delay
Another car performance function that is likely to suffer under a bad sensor is acceleration. If the fuel can’t get to the engine fast enough because the air flow sensor isn’t picking up the correct viscosity and density of the air, especially as it begins to enter the engine at higher speeds, then the fuel-air mixture is will be altered once more.
6- Excessive fuel consumption
Have you noticed that you have to refuel more fuel? If you’re making more fuel stops than seems normal, then the air mass sensor could be to blame. A faulty sensor could be sending incorrect information to the powertrain control module (PCM), which in turn could be causing the vehicle to consume more fuel than normal.
7- Smell of unburned fuel in the exhaust
A faulty air mass sensor could be supplying too much fuel to the engine. If this is the case, unburned fuel could be blown out of the exhaust, causing the smell of fuel in the air around your car.
Cleaning the air mass sensor
Most of the problems on our list are caused by dirt and debris buildup on the sensor wires. The ideal is to review this piece twice a year or every six months. Many mechanics also recommend changing the air filter when servicing. Anyone with a little bit of mechanical knowledge can get this job done:
You will need: a standard flat head screwdriver, a plastic bag, cleaning alcohol, and sensor cleaner.
1- Extract the sensor
You should be able to find the sensor in the airbox and you can remove it with a flat head screwdriver. Be very careful not to break any of the wires during the removal process.
2- Clean the sensor
Use the cleaning spray on the sensor or simply put it in a plastic bag and rub it gently with alcohol until the part is free of dirt and debris.
3- Reinstall the sensor
Allow the sensor to air dry before reinstalling it in the air box. Take your car for a test drive and you should notice an increase in engine response and performance.
In conclusion
If nothing else works… It may be the case that the cleaning process is failing to get the sensor to work at normal levels of performance, in which case the part is most likely completely broken. In these cases, we strongly recommend that you replace your air mass sensor. Fortunately, this is a relatively easy task – if you give yourself a little time and patience.
