Wondering what to do after replacing mass air flow sensor? Here is my detailed guideline. In most vehicles, an airflow sensor is useful in determining the quantity of air entering the engine.
When the mass airflow sensor (MAF) has a fault, it leads to rough idling, illuminated check engine light, and misfiring.
Sometimes, you might replace the mass airflow sensor and still experience check engine light flashing issues.
If your mass airflow sensor has an issue, it would be best to replace it immediately.
This article gives you tips on what to do after replacing the mass airflow (MAF) sensor.
What Is Mass Air Flow Sensor?
Mass airflow is a useful element in determining the air quantity that enters your car’s engine.
When calculating the amount of fuel to give the engine, the power control module uses the mass airflow sensor signal; it means more fuel if there is more air.
There are a variety of MAF sensors in different cars. The most popular types are hot film and hot wires, but they function similarly.
The power control module transmits electrical currents to heat the hot film or the hot wire element to measure the airflow.
The airflow then cools the element and reduces its electrical resistance to increase current demand. The power control module now uses the increasing current demand to determine the air entering into the engine.
Please note that not all vehicles use a MAF sensor; others have a Speed Density System.
Will a Bad MAF Sensor Throw A Code?
When the mass MAF sensor has a problem, it will likely show codes.
There are diagnostic trouble codes related to bad mass airflow sensors. At the same time, fuel or air ratio and misfires codes also indicate an issue with the MAF sensor.
Therefore, if you notice that the check engine is illuminating, use a code reader or a scan tool to retrieve the corresponding trouble codes.
It is important to note that a bad mass airflow sensor will not always throw a code, especially in old cars fitted with self-diagnostics.
Replacing Mass Air Flow Sensor and Check Engine Light Flashing
Unhook the battery if you realize the check engine light is illuminating after you replace the MAF.
Disconnecting the battery for about ten minutes allows the computer to forget the old learned parameters, resetting to factory parameters. After resetting, it moves to learning mode to understand the parameters of the new mass air flow sensor.
However, you should note that engine light flashing is not only a symptom of bad installing of the mass airflow sensor and can be caused by a fault in other parts.
What to Do After Installing New MAF?
After installing a new mass airflow sensor, your vehicle should recognize the new device and everything work properly.
However, sometimes the engine might not accept new mass airflow sensors. So, as a car owner, the first thing that will cross your mind is that the sensor is broken, a very rare occurrence.
So if your new MAF sensor does not work, here is what to do;
Ensure what you ordered is the right item and you received exactly that.
Check the number on the old part and compare it with OE- numbers in the seller’s description. If not sure of the exact fir for your car, check with your supplier.
After replacing the MAF through self-adaptation, the control unit learns the right data. The “learning” process might take longer, and at this time, the engine runs unevenly, and you could get the impression that the new airflow is defective. Let the engine run idle for 20 minutes and if it does not help, unhook the battery for 10 minutes.
Before installing the new MAF sensor, do the following;
- Compare the OE-number of the older MAF with your supplier’s reference number
- Replace the air filter and also clean the air filter housing.
- Clean the air hose to ensure it does not have oil or dirt
- Ensure no sign of corrosion on the connector and that it is clean.
If you still have an issue after installing the new MAF, do the following;
- If your vehicle still has issues, run your engine idle for 20-30 minutes.
- Disconnect your battery for about 10 minutes to reset your ECU.
- Ensure you have also checked the other parts components that can lead to such signs to ensure that it was not only the airflow sensor broken.
How Do I Reset My Mass Airflow Sensor?
Do you want to reset your mass airflow sensor; here are the steps to follow;
- Start your engine and allow it to warm up to normal operating temperatures.
- Turn off the ignition switch.
- Disconnect the harness connector for the mass airflow sensor.
- Restart your engine and allow it to rest for not less than 5 seconds.
- You can now stop your engine and hook the mass airflow harness connector back.
- Ensure that you display the DTC P0 102.
- You can now delete the DTC memory.
It is important to note that this might not function similarly for all the vehicles.
Should I Disconnect Battery When Changing MAF Sensor?
You need to disconnect the battery from the ground cable and remove the original MAF sensor before installing the new mass air flow sensor.
Unhooking the battery when installing the MAF sensor ensures you prevent any possible injuries and accidental starting. Disconnecting the battery also disables electric cooling fans, which may be transmitted even after turning off the ignition and removing the keys.
At the same time, disconnecting your battery for only ten minutes cannot cause any damage.
So disconnecting it will be great for your safety and cutting down expenses you might accrue if accidents arise because of installing your MAF sensor with the battery on.
On What to Do After Replacing Mass Air Flow Sensor
What do you do after replacing the MAF? If the check engine light still illuminates, reset the entire system by disconnecting the battery.
Disconnecting the battery and leaving it for about 10 minutes will allow your car to adapt to the new part and ensure everything is working properly.
If your car still has a problem, run the engine idle for about 20-30 minutes. At the same time, ensure you check your car properly if you still have an issue after replacing the MAF sensor.
It might be improperly installed or broken so ensure you ascertain where the issue is at exactly. A broken or faulty mass airflow sensor is inconvenient and dangerous and can damage other important components like a catalytic converter. So, the earlier you work on it, the better.
Hi I’m Marshall based in 1478 Doctors Drive Santa Monica, CA. I’m your DIY Car Repairman with more than 5 years experience in automobile repair, a skill I learned from my old man.
I started this blog to share my experience on both simple and technical aspects of your car.