(MAF) Mass Air Flow Sensor : How it Works, Symptoms & Replacement Cost

MAF Sensor

Various types of sensors are used in modern vehicles, which provide signals to the ECM about the functioning of engine parts. The vehicle’s ECM uses these signals to successfully operate the engine and other functions, including determining the proper fuel mixture and ignition timing.

Through this article, we will learn in detail about the mass air flow sensor used in the engine. Like, what is a mass air flow sensor, what are the causes and symptoms of a bad mass air flow sensor, and what is the replacement cost?

What is A Mass Air Flow (MAF) Sensor?

The mass air flow sensor is a component used in the intake air system of modern vehicle engines to detect the mass flow rate of air entering the internal combustion engine. The mass air flow sensor signals the vehicle’s ECU about the volume and density of air entering the combustion chambers, and based on the data provided, the ECU controls fuel injection and ignition to ensure efficient engine operation, performance, fuel economy, and emissions control.

A faulty or dirty MAF sensor can disrupt this delicate balance, causing engine performance issues and increased emissions. Therefore, it requires regular maintenance for efficient operation.

(MAF) Mass Air Flow Sensor Location

The location of the mass air flow (MAF) sensor varies depending on the make and model. In most vehicles, the MAF sensor is found in the air intake system between the air filter and the throttle body. However, in some vehicles, this sensor may be located near or adjacent to the air filter housing. In some rare cases, it may also be inside the throttle body.

How Does The Mass Air Flow Sensor Work?

The mass air flow sensor transmits a signal about the quantity and temperature of air coming from the air filter into the engine’s internal combustion chamber to the vehicle’s ECM unit during engine operation.

Due to which the vehicle’s ECM determines the ratio of air and fuel in the mixture, sends the right amount of fuel to the engine, and determines the correct ignition timing. Due to which the engine successfully delivers power performance without any problems or excessive fuel consumption. For the engine to start successfully, it is absolutely essential that the correct amount of fuel is ignited in the internal combustion chamber of the engine.

Types Of Mass Air Flow Sensor

  • Hot Wire MAF Sensor
  • Hot Film MAF Sensor
  • Vane MAF Sensor

However, it is also classified on the MAF sensor wiring diagram depending on the make and model of the vehicle.

  • 4 wire mass air flow sensor
  • 5 wire mass air flow sensor
  • 6 wire mass air flow sensor

Bad Mass Air Flow Sensor Symptoms

Causes Of Bad Mass Air Flow Sensor

  • Clogged or Dirty Air Filter
  • Damaged or broken MAF sensor & wire
  • Dirt build-up at the sensing point of the MAF sensor
  • Faulty ECM
  • Damaged MAF pin or connector

Mass Air Flow Sensor Codes

When you scan a vehicle’s system with an OBD-II digital scanner for problems with the mass air flow sensor. You may then see a variety of trouble codes related to a faulty MAF sensor in the scanner.

MAF Sensor Trouble Codes

  • P0101 – Mass or Volume Air Flow Circuit Range/Performance
  • P0102 – Mass or Volume Air Flow Circuit Low Input
  • P0103 – Mass or Volume Air Flow Circuit High
  • P0104 – Mass or Volume Air Flow Circuit Intermittent
  • P0110 – Intake Air Temperature Sensor 1 Circuit

How To Check & Troubleshoot The Mass Air Flow Sensor?

You will need to repeat the following process to check and troubleshoot the mass sensor.

  • First of all, scan the vehicle’s system with an OBD digital scanner. You will get the trouble codes related to the mass air flow sensor problem; act according to these trouble codes.
  • Reset the trouble code from the ECM with the OBD scanner once. If, after a while, the trouble code for the MAF sensor is displayed again, then this process will have to be repeated.
  • First, check the air filter. If the air filter is clogged, replace it with a new one.
  • Next, check if the MAF sensor is damaged.
  • Remove, clean, and re-install the mass air flow sensor.
  • For this, check the reading of the mass air flow sensor with a multimeter when the ignition is on. This reading should be between 7.5 and 14 volts.
  • Now that the engine is running, check the reading of the MAF sensor with a multimeter. Now this reading should be 0–5 volts.
  • If the reading of this sensor is coming wrong. So this indicates a bad MAF sensor. Then a new mass air flow sensor should be substituted.
  • Also check the wiring at the mass air flow sensor. if any of the wires connected to the MAF sensor are damaged. Then repair the wire or replace the wire with a new one.
  • Check the ECM unit. If you find the ECM to be faulty, then get it repaired or replaced. However, replacement of the ECM can be a costly affair.


  • The MAF sensor should always be protected from oil and water.
  • Any sensor should be protected from falling. because falling down can cause sensor failure or damage.
  • Never hit the MAF sensor when opening or fitting it.
  • Never blow air with high pressure directly while cleaning the sensor.
  • Never check sensor with direct supply from battery.

How To Replace A Mass Air Flow Sensor?

  • First of all, remove the positive wire from the battery.
  • Next, remove the wire connecting to the mass air flow sensor.
  • Now you have to carefully take out the mass air flow sensor by opening it.
  • After this, you fit the new mass air flow sensor.
  • Now connect the wire connector of the mass air flow sensor.
  • Then connect the removed positive wire to the positive terminal of the battery.
  • After this, if the check engine light is still illuminated in your vehicle’s cluster meter, you have to reset all trouble codes one time with an OBD scanner.
  • Through this process, you can replace the mass air flow sensor.

Mass Air Flow Sensor Replacement Cost

Car’s, SUV’s & Trucks Mass Air Flow Replacement Cost Is –

  • Mass Air Flow Sensor Cost: $130 to $250
  • Mechanic Labor Cost: $70 to $100
  • Total MAF Replacement Cost: $200 to $350

Generally, the replacement cost of a mass air flow sensor in cars and trucks can range from $200 to $350. This cost will be inclusive of the labor cost of the mechanic. Taxes and fees are not included in this estimated cost.

The cost of a mass air flow sensor can range from $130 to $250. And the labor cost to have the mass air flow sensor replaced by a mechanic can range from $70 to $100.

In fact, air mass flow sensor replacement cost depends on the model of vehicle, type of MAF sensor, and mechanic labor costs. If you are experienced with replacing your vehicle’s mass air flow sensor yourself, then the replacement cost can save the mechanic’s labor costs.


Q. Can you drive without the mass air flow sensor?

Yes, you can drive a vehicle with a bad mass air flow sensor. But driving a vehicle with a bad mass air flow sensor for an extended period of time is not recommended by the vehicle manufacturer or vehicle mechanics. because it badly affects the functioning of the engine of your vehicle.

Q. Can you clean the mass air flow sensor?

Yes, instead of replacing the mass air flow sensor, you can clean it and use it once. If, in spite of cleaning, you still face problems related to this sensor, So after this, you have the option of replacing it with a new one. However, this can be a matter of cost. Because replacement of the mass air flow sensor can cost between $250 to $350.

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