TECHNOLOGY

Nissan Altima Mass Air Flow Explained

The engine control unit in a Nissan Altima uses air flow data to adjust the ratio of air to fuel. A dirty or faulty mass air sensor can make it difficult to start the engine or cause a variety of performance problems. Learn more about the symptoms of a bad mass air flow sensor and how to locate, clean or replace this part.


What Does a MAF Sensor Measure?

The MAF sensor situated between the air filter housing and intake manifold in your Nissan Altima measures the rate of airflow into the engine. The sensor housing contains a wire element heated by electrical current. More current is drawn as more air moves over the sensor. This sensor sends digital signals to the engine control unit, which controls the fuel injection system. You can try to clean this sensor or get replacement Nissan Altima auto parts for the year make and submodel of your vehicle.


Locating the MAF on Your Nissan Altima

The ease of accessing the MAF sensor varies across the six generations of Nissan Altima models released to date. In earlier models, you will need to open the airbox cover to access the sensor assembly. Disconnect the negative battery terminal and the wiring harness for the sensor. Loosen the clamp on the air intake hose and remove the airbox cover. The MAF sensor assembly is bolted to the cover. Torx bolts secure the sensor. You will need to remove these bolts to clean and replace the sensor. Replacement parts include the full assembly.


The MAF sensor is located behind the airbox on later models, making it easier to access. Disconnect the negative battery terminal and release the wiring harness by pressing a tab. Remove two Phillips screws and pull out the sensor. Use a spray cleaner formulated for MAF sensors and do not touch or try to scrub the wire element. Spray 10 to 15 short bursts of cleaner into the sensor from every side and shake gently to dislodge debris. Allow the sensor to dry completely before reinstalling. Replace this component by plugging a new sensor into the wiring harness and securing in place.


Sings Your MAF Sensor Isn’t Working Properly

A malfunctioning MAF sensor in a Nissan Altima can keep the engine from obtaining sufficient fuel. If the ratio of air to fuel is being miscalculated, your vehicle may experience performance issues. A lack of engine power, weak acceleration or stalling may occur if the system runs too lean or rich. Altima models with automatic transmissions may experience hesitation or jerk when shifting gears. Engine performance may also be improved with replacement Nissan Altima oil filters or air filters.


A vehicle diagnostic can determine whether a Check Engine light is accompanied by error code P0101 MAF Circuit Range/Performance or a related code. A clogged or faulty sensor can also result in system too lean or system too rich codes. A scan tool that measures the amount of air flow at different RPMs and a digital multimeter for testing voltage can identify the cause of sensor problems.