Check engine light on after replacing MAF sensor. Causes and solutions

Having a check engine light due to a faulty mass airflow sensor is a common problem experienced by car owners. The problem is also quite common after replacing the MAF sensor or when the vehicle has a series of electric issues.

Furthermore, a check engine light might pop up on your car if the has other issues besides a bad MAF sensor and you don’t know about.

Take the car for diagnosis whenever your vehicle shows a check engine, and you suspect it could be a problem with the MAF sensor. Establishing the actual problem with the sensor helps you take real actions towards fixing the problem.

When the MAF light shows because of an electrical fault, go to a mechanic to fix the problem and avoid finding a quick fix.

But, there is a simple solution you can try when the MAF sensor light pops up after replacing the MAF sensor, you can try to reset your vehicle’s computer using the right scanner and software for your car.

Common causes why the check engine light is still on after replacing the MAF sensor.

After replacing the MAF sensor, having the check engine still on can be frustrating. Many people do not seem to know why it is still on and what to do to switch it off.

While most car manufacturers and technicians recommend resetting the vehicle’s computer, most people still believe that something went wrong or they have other issues that didn’t know about.

1. Poor replacement

One of the most common causes of check engine popping up after MAF sensor replacement is having a faulty replacement. When replacing the sensor, especially at home, most people do not accurately make the replacement, causing the check engine light to appear again.

2. Not resetting the car’s computer (ECU)

The second and the most common problem is replacing the MAF sensor and forgetting to reset the vehicle’s computer. Resetting the car’s computer and ensuring all codes from the sensor are synched with the computer.

The codes are an essential tool in helping a technician detect a problem with the MAF sensor. Hence, when some codes are not in sync with the vehicle’s computer, you will have the check engine light showing up again.

The task is very simple if you have the correct tools and software to do it the right way.

3. Other problems related to Mass airflow senso

When the air intake passages are not transparent or when the air filter is faulty, you could get a check engine light on in the dashboard related to a faulty MAF sensor.

The key to resolving the problem is a thorough diagnosis and a qualified technician to fix the air filter. Having the air intake systems clean will eliminate the pain.

Do I need to disconnect the battery when changing MAF?

It’s essential to disconnect the battery whenever you are replacing a MAF sensor. Disconnect the battery from the ground cable to ensure no current flows through the vehicle’s electrical cable. The disconnection also helps prevent any short circuit of the wires during the process. 

First, one is advised to disconnect the wiring to the harness plug before removing the MAF sensor. Also, disconnect the IAT sensor, and ensure the air cleaner tubes are disconnected from the engine.

What would happen if the airflow sensor is left unplugged? Your vehicle may run with the MAF sensor unplugged, but it will lead to the check engine popping up. Also, never plug in the MAF sensor when the vehicle is running as it could damage the engine. 

Whenever you are working on the sensor, ensure the battery is disconnected as it leads triggers engine error codes such as P0101 and P0102. Thus, disconnecting the battery helps you prevent more problems with your engine. When fixing the MAF sensor, having the battery on can easily short circuits the mass airflow sensor, leading to more problems. 

After fixing the MAF sensor, it takes a few seconds to re-calibrate and work flawlessly. However, if this is not the case, check the engine analyzer or the cold air intake pipes for any fault. If everything seems perfect, drive the vehicle for a few minutes, and the sensor should synch and work perfectly. 

Finally, whenever you have a faulty MAF sensor, the first step is running a diagnostic to establish the cause of the problem. On confirming the problem, get a qualified technician to fix it or diligently resolve the issue from your garage.

After the fix and you still get the check engine light, you could face problems with the air intake systems or problems discussed above. Remember to remove the battery when fixing the MAF sensor to avoid more problems with your wiring systems.

Scroll to Top