How Long Does it Take for a New MAF Sensor to Work?

How Long Does it Take for a New MAF Sensor to Work

MAF is an acronym for the Mass Air Flow sensor. It is a very important part of cars that have electronic fuel injection systems because the mass air flow sensor measures the amount of air that enters the engine.

It is used to determine the amount of air that enters the engine of the car and also the amount of fuel that the car’s engine would need.

However, if the mass air flow sensor goes bad, and you replace it with a new one, the question is, how long does it take for a new MAF sensor to work?

Normally, the newly replaced mass air flow sensor is supposed to start working as soon as it is installed. You are however urged to remove the battery from the connectors and wait between 15 – 20 minutes before starting the car.

Do MAF Sensors Start Working Immediately After a Replace?

Most times, the mass air flow sensor doesn’t start working immediately after it has been replaced.

As reiterated earlier, the engine needs to be completely drained of energy so that the engine’s electronic control unit begins to acclimatize itself with the newly replaced part and starts processing information from it.

After you have replaced the mass air flow sensor, you should turn off your car’s engine and then open up the bonnet of your car.

Find the negative part of the two wires that are connected to the top of the battery and remove that part from the battery so that the energy is drained out completely.

Moreover, remember that there are two types of mass air flow sensors but in these modern times, car manufacturers have chosen to use the hot wire mass air flow sensor.

The hot wire coupled with additional sensors and inputs successfully sends information to the engine’s electronic control unit and it can determine the date at which air flows into the engine.

How Long Does it Take for a New MAF Sensor to Work?

Once you have replaced the faulty mass air flow sensor, you can take the battery off and wait for about 15 – 20 minutes before restarting the car.

The mass airflow sensor is not a device that comes on and goes off, when it’s good or newly fixed, it starts working immediately.

However, you need to uncouple the car’s battery and leave it for about 15 – 20 minutes so all the energy is completely drained from the car’s engine.

The engine’s electronic control unit is a computer and when a part is newly replaced, it might not recognize the new part and still keep displaying the information it got from the former part, that’s why the energy needs to be drained.

Meanwhile, sometimes, error codes get stuck on the car’s electronic system and if you don’t want to take your battery off to drain the car’s electronic system, there’s only one other thing you can do to confirm that the mass air flow sensor is recognized by the engine’s ECU.

The only other thing you can do is keep the engine running because the mass air flow sensor only works when the engine has been working and is already hot, so you can keep driving for a couple of miles before the mass air flow sensor starts functioning.

How to Tell if MAF Sensor is Working.

The mass air flow sensor is responsible for measuring the air intake of the vehicle’s engine so when it is working there are a few things that you’d notice.

  • Smooth Acceleration: The vehicle has no difficulty working and it runs smoothly. With this, you are certain that the mass air flow sensor is reading correctly and working very well.
  • The Engine Doesn’t Stall: When the mass air flow sensor is functioning properly, the engine does not just stop turning.
  • Check Engine Light: When the mass airflow sensor is in a good condition, the check engine light with the trouble code for faulty MAF does not come on.
  • Proper Fuel Economy: The engine properly manages fuel when the mass air flow sensor is functional. It allows the engine to add or inject more than the necessary fuel.
  • No Difficulty in Starting: As long as the mass air flow sensor is good, the vehicle would easily start up without any difficulty.
  • Stability of Engine Power and Functionality: The engine’s power would decrease evidently when the mass air flow sensor is in a bad condition but when it’s not the engine functions optimally.

How to Troubleshoot MAF Sensor

Troubleshooting a MAF sensor can be a bit tricky but these guidelines will help you troubleshoot successfully without harming any other part of your car’s engine. You need a digital meter for this exercise

1. Open The Bonnet of Your Car

Firstly, you need to open up the bonnet of your vehicle to have access to the engine parts.

2. Locate the MAF Sensor

Locate the MAF sensor, it is usually between the air filter and the throttle, in case your car is different, you should check your car’s manual to know where it would be.

The mass air flow sensor is usually a small block-shaped or cylindrical section that is mounted as part of the air duct.

3. Check the Air Duct

After you have located the MAF sensor, check for the air duct, it is usually after the where the air filter is housed. Now, check the connectors and make sure that they’re in contact.

4. Unplug the MAF Sensors Connector

Unplug the MAF sensors connector and thoroughly look through the terminal to see if there’s any damage or if it’s clogged up with dirt. Make sure that none of the wires are burnt by gently pulling the wires.

5. Set Your Digital Meter at 20 Volts DC

Now, set your digital meter at 20 volts DC then connect the red wire of the meter to the connector’s power terminal, then put the meter’s black wire to the ground (the negative terminal on your car’s battery)

6. Turn The Ignition On

Turn on your car but don’t start the engine, the meter should into the range of 10 to 13. If it doesn’t then there’s a fault in that part between the car computer and electrical connector.

7. Turn Off the ignition

Once everything is set, turn off the ignition


The MAF sensor, also known as the air meter is a very key component of the car’s engine it should be properly maintained and checked regularly to see if it’s working.

When you notice any irregularity, drive down to a repair shop and get it fixed because a faulty MAF sensor damages the car gradually until it eventually becomes a really big issue that will cause you to spend a lot more.