The Mass Air Flow Sensor (MAF) determines the amount of air entering your car’s engine and transmits data to the Engine Control Unit (ECU).
If the signal is not within the normal operating range, it will display the mass air flow sensor code P0101 and illuminate the vehicle’s “Check Engine” light.
Other causes of code P0101:
- MAF sensor or wiring is too close to higher voltage components such as the alternator or ignition wires, which can interfere with the signal to the ECU.
- Engine vacuum leak
- Damaged or disconnected air intake boot (snorkel)
- Obstruction in the mass airflow sensor
- Clogged or improper installation of air filter
- Mass air flow sensor is contaminated with oil
- Clogged catalytic converter
Mass air flow sensor replacement costs usually range from $224 to $371. Fortunately, replacing the MAF Sensor is relatively simple: disconnect the mass airflow sensor by simply opening your vehicle’s air box then use a flathead screw to remove it. Auto Parts Warehouse provides affordable yet high-quality replacement mass air flow sensors that you can find right here: https://bit.ly/2NNFS18
What are the symptoms of a bad mass air flow sensor?
Common symptoms of a faulty MAF are:
- Engine stalling
- Difficulty starting
- Rough idling
- Less engine power
Testing a MAF Sensor
Mass air flow sensors of some older vehicles can be tested using a voltmeter by measuring signal voltage at different engine speeds and comparing it to a specific range. With newer cars, you may use a scan tool to test the digital signal produced by the air flow sensor.
How to Test a Mass Air Flow Sensor
First, locate the MAF Sensor in the air cleaner assembly, usually in between the air filter housing and throttle body. In some models, it’s inside the filter housing. Proceed to clean it (including wiring) and remove any foreign object clogging it up. You may refer to your vehicle’s manual to locate your MAF Sensor.
In the air duct next to the air filter housing, look for an electrical connector that you can back probe and plug it into the MAF Sensor. If the wires can’t be used, pierce them using a pin. You may want to wrap it with electrical tape to prevent rusting.
Once done, identify the power, grounds, and signal wires on the electrical connector. Refer to your vehicle’s manual for this information.
There are three (3) basic tests to check your MAF Sensor (using a multimeter):
- Ensuring the MAF Sensor is getting 10 to 12 voltages – This is the usual result when the ignition is switched on, coming from the fuse or a relay.
- Ensuring the MAF Sensor is getting ground – The MAF Sensor typically gets ground from the engine/chassis via a fuel injection computer. Use a wiring diagram from the engine management system.
- MAF Sensor signal test – Make sure the MAF Sensor generates the correct signal, either analog or digital. Set your meter to 10 DC V. Start your engine and put it on idle. Back probe the signal (red probe) and ground wires (black probe). Depending on your MAF sensor, your voltage reading should be between 0.60 to 0.80 volts at idle and between 1.5 to 3.0 volts when between 2,500 and 3,500 RPMs.