- Turn the ignition switch off.
- Set the multimeter to a frequency scale.
- Connect the black lead of the multimeter to the negative terminal of the battery or chassis and the red lead to the signal terminal of the MAF sensor.
- After isolating the connections, start the engine.
- If the frequency of the signal terminal is around 30 hertz, then the frequency wire is working properly.
What are the symptoms of a bad mass air flow sensor?
Symptoms of a Bad MAF Sensor
- Check engine light
- A Drop in acceleration
- Rough or Jerky Acceleration
- Hard starting condition
- Black Smoke From Exhaust Pipe
- Rough idle
- Misfires
- Changed Fuel Consumption
What are the problems for a mass air sensor?
What causes MAF sensor to fail in Sentra?
- Dirt accumulation. The most common cause of a malfunctioning MAF sensor in Nissan Sentra is dirt and grime accumulation on the sensor.
- Too many miles on the sensor. The mass air flow sensor is a wearing part. ...
- Water damage. ...
- Oil damage. ...
- Bad connector or electrical wires. ...
What are the symptoms of a bad Mas sensor?
Symptoms of a Bad Mass Air Flow Sensor are given bellow
- Hesitation and Jerking of the Car During Acceleration: A Bad Mass Air Flow Sensor will definitely reduce the quality of driving the car. ...
- The Ratio of the Air Fuel will be very Rich: As previously we knew how a Mass Air Flow Sensor works. ...
- The Ratio of the Air Fuel will be very Lean:
What do you use to clean mass air flow sensor?
To clean the sensor surface, you should only use a Mass Air Flow Sensor cleaner (MAF cleaner) or electrical contact cleaner. Try not to touch the sensor surface with your hands as grease and dirt from your hands can damage it. Let the sensor surface dry completely before refitting it to the vehicle. 4. Refit the mass air flow sensor to the car.
Can I test MAF with multimeter?
A basic digital multimeter (DMM) with at least 10 Megohms of impedance (to protect circuits and your car's computer) will help you test your MAF sensor. In some cases, though, you'll need a DMM with a frequency scale, depending on the type of MAF sensor your car uses.
How do you know if you have a faulty mass air flow sensor?
Stalling, jerking, or hesitation during acceleration A bad MAF sensor can cause too much fuel to be left in the combustion chamber, creating untimed detonations. You'll experience this as poor drivability such as hesitations or sudden jerking motions, particularly during acceleration.
How much resistance should a mass air flow sensor have?
2.5 – 3.1 ΩThe MAF resistance is checked as follows: ohmmeter is connected between terminals 2 and 3 of the MAF sensor's connector - the resistance should be 2.5 – 3.1 Ω.
What is a normal mass air flow sensor voltage reading?
Depending on your MAF sensor, your voltage reading should be between 0.60 to 0.80 volts at idle. If your reading indicates 12 volts or pretty close to it, you are probing the power wire, not the signal wire).
Will my car run if I unplug the MAF sensor?
If you unplug the mass air flow sensor the car will start. If you try to plug it in while it's running the car will die.
When I unplug my MAF sensor car runs better?
The MAF sensor measures air weight in grams per second and air temperature and if either of those two are off then the ECU may command a leaner or a richer mixture. By disconnecting the sensor the ECU switches to limp mode and the car may idle better .
How do you trick a MAF sensor?
How to Reset Mass Air Flow Sensor?Start your car's engine.Allow it to warm up to its normal operating temperature before continuing.Turn the ignition switch to the OFF position.Disconnect the connection for the mass airflow sensor harness.Start the engine of your car.More items...•
How do you reset a mass air flow sensor?
Start engine and warm it up to normal operating temperature.Turn ignition switch OFF.Disconnect mass air flow sensor harness connector.Restart engine and let it idle for at least 5 seconds.Stop engine and reconnect mass air flow sensor harness connector.Make sure DTC P0102 is displayed.Erase the DTC memory. “
How do I test a sensor with a multimeter?
0:302:36How to test a Car Sensor - YouTubeYouTubeStart of suggested clipEnd of suggested clipTake our two leads. And we're gonna touch. Each side. And I'm getting all over the place. Five eightMoreTake our two leads. And we're gonna touch. Each side. And I'm getting all over the place. Five eight nine between five and nine mmm. So there's three point six three point five anyways.
What is a good MAF reading at idle?
With the engine at idle, the MAF's PID value should read anywhere from 2 to 7 grams/second (g/s) at idle and rise to between 15 to 25 g/s at 2500 rpm, depending on engine size. Most manufacturers provide specifications for air flow at idle; some will provide specifications at several engine speeds.
Will a bad MAF sensor throw a code?
Often, when there's an issue with the MAF sensor, your car's primary computer—often referred to as the powertrain control module (PCM)—will turn on the check engine light and store a diagnostic trouble code (DTC) in its memory.
When should I replace MAF sensor?
Generally, you should get at least ten years of driving out of your mass airflow sensor, but this can vary depending on several factors. Over time, contaminants such as carbon will find their way into the mass airflow sensor, creating a buildup which makes it harder for air to pass through.
Is it better to clean or replace a mass air flow sensor?
MAF sensors can become damaged, but more often they just get too dirty to do their job well. In this case, they can be cleaned but if it is a mechanical or electrical failure, they must be replaced.
How do you reset a mass air flow sensor?
Start engine and warm it up to normal operating temperature.Turn ignition switch OFF.Disconnect mass air flow sensor harness connector.Restart engine and let it idle for at least 5 seconds.Stop engine and reconnect mass air flow sensor harness connector.Make sure DTC P0102 is displayed.Erase the DTC memory. “
Will a bad MAF sensor throw a code?
Often, when there's an issue with the MAF sensor, your car's primary computer—often referred to as the powertrain control module (PCM)—will turn on the check engine light and store a diagnostic trouble code (DTC) in its memory.
What are the symptoms of a faulty map sensor?
What to look out for in a failing MAP sensorRich air-fuel ratio: Look for rough idle, poor fuel economy, slow acceleration and a strong smell of gasoline (especially at idle)Lean air-fuel ratio: Look for surging, stalling, lack of power, hesitation on acceleration, backfiring through the intake, and overheating.More items...
What to check for when cleaning MAF sensor?
Check your local auto parts store, they will have MAF sensor cleaning spray. After having checked for contamination the other things that you must check for (and eliminate if present) are: That the engine does not have any vacuum leaks. That there are no ignition system misfires.
How to clean a MAF sensor?
If cleaning the MAF sensor, use an electronics spray cleaner to do it with. This in itself may solve your problem. Don't use carb or brake clean spray. These solvents can damage the sensor. Also, don't attempt to physically clean the sensor with anything. Check your local auto parts store, they will have MAF sensor cleaning spray.
Why is my MAF sensor contaminated?
Why? Because this MAF sensor is a hot-wire type that easily becomes contaminated with dirt and stuff from the air filter not performing its job. Cleaning this type of sensor is easy since the hot-wires are clearly visible to the eye (with the sensor removed).
Can an ignition system misfire?
That there are no ignition system misfires. A misfire condition will skew the results of the test you'll perform here.
Can a MAF sensor be tested without a scan tool?
A MAF sensor can be tested without a scan tool. How? With a digital multimeter. Yes, a digital multimeter can be used in testing the Mass Air Flow (MAF) sensor.
When testing a mass air flow sensor, do you need to know the voltage?
Another very important thing to know, when testing a mass air flow sensor, is that we don't need to know the exact voltage value for certain engine RPM. What is important is that the MAF sensor signal should increase when you accelerate the engine and should decrease once you let the engine return to idle.
What happens when a mass airflow sensor fails?
I can tell you, from personal experience, that in nine out of 10 cases when the mass airflow sensor fails, it simply stays stuck producing one specific voltage (or Hz) value no matter how much you accelerate the engine.
How Does The MAF Sensor Work?
To be able to understand how to test a MAF sensor, it's always good to know how it works.
How to verify MAF signal?
The MAF signal has to be verified with the sensor connected to its electrical connector and with the engine running. This means that you'll need to use either a back probe or a wire piercing probe to access the signal within the wire. 1. 2. 3.
What is the next step in a MAF sensor?
If the MAF sensor is getting Ground, then the next step is to make sure that it's generating a MAF signal. Testing for the MAF signal: If the mass airflow sensor is getting power and Ground, then the next step is to make sure it's generating a correct signal. This signal will either be and analog signal or a digital signal.
How many wires does a MAF sensor have?
What complicates testing a MAF sensor is the fact that it could have 3, or 4, or 5 wires coming out of its connector.
Where does the 12 volt sensor come from?
These 12 Volts usually come from a fuse or a relay. If the mass airflow sensor is being fed with 10 to 12 Volts, then the next step is to make sure it's getting around. Making sure the MAF sensor is getting Ground: Depending on the make and model of your car, the mass airflow sensor will get ground from the engine/chassis or through ...
