How to Fix P0102 Code: Mass Air Flow (MAF) Sensor Circuit Low Voltage Input

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Voltmeter on the car engine

If your "check engine" light comes on and you see the code P0102, don't worry. You can fix this issue yourself without spending a lot of money at the mechanic. This blog post will discuss what the code P0102 means and how to fix it.

What is Code P0102?

P0102 is a diagnostic trouble code for "Mass Air Flow (MAF) sensor Circuit Low Voltage Input." This means a problem with the MAF sensor. The MAF sensor measures the amount of air that is entering the engine.

The MAF sensor must be within the correct voltage range for the Engine Control Unit (ECU) to function correctly. When the Powertrain Control Module (PCM) detects a lower voltage output than its normal operating range, it will trigger the P0102 code.

Symptoms of Code P0102

When the MAF sensor is not working properly, you might experience various symptoms. Some common symptoms are:

  • Check Engine Light coming on
  • Run slightly erratically
  • Rough idling
  • Too low fuel consumption
  • Exhaust smoke
  • Engine hiccup or stalling
  • Clogged air filter

Causes of Code P0102

When diagnosing this issue, you must know all its possible causes. A few different things can cause the P0102 trouble code. Here are some of the most common causes:

  • Dirty or faulty MAF sensor
  • A hole in the air filter
  • Vacuum leaks
  • Faulty PCM
  • Damaged or Failed Mass Air Flow Sensor
  • Damaged sensor circuit wiring or connectors 

How to Diagnose Error Code P0102

Now that you know all the causes of this issue, you can start diagnosing it. Are you mechanically inclined? If you are unsure of your automotive abilities, you can have this issue checked by a professional. Let's get started!

Scan for other Codes

Get your OBD scanner and plug it into the vehicle's diagnostic port. Turn the ignition on, but don't start the engine. The scanner will automatically detect the error code(s) stored in your car's computer.

Take note and clear all the retrieved codes and try to start the engine. If the code returns, proceed to check the components.

Perform Visual Inspection

Check your air filter and ensure it is not dirty or clogged. A dirty air filter can cause the engine to misfire and set a P0102 code. Replace if necessary. Also, visually inspect your MAF sensor for dirt, debris, or damage. Use a MAF sensor cleaning kit to clean the sensor if necessary.

Check for Vacuum Leak and Cracks

Don't forget to check your vacuum hoses for leaks. A vacuum leak will allow air to escape from your engine. Small cracks or holes can cause the engine to misfire and set a P0102 code. Replace damaged hoses.

Test the Mass Air Flow MAF Sensor Output

If there are any signs of an out-of-range condition, reconnect all of the sensor's terminals to ensure that it is getting appropriate input and ground signals. If the MAF sensor is still not functioning properly, replace it.

How to Fix Code P0102?

If you have performed all the diagnoses and found out that that MAF sensor is the culprit, it's time to change it. You can do this by yourself, but take it to a mechanic if you don't feel confident enough. Here's how to do it:

  1. Start by locating your MAF sensor (it is usually located between the air filter box and intake hose)
  2. You will see an electrical connection that plugs in at the side. Remove the plug and loosen the bolts on the air filter box and lift it up
  3. Use the key included in your new MAF sensor to slide out the old sensor from the box.
  4. Put your new sensor and make sure it is in place.
  5. Install the air filter box back in place and screw in the bolts.
  6. Reconnect your electrical plug to the new MAF sensor.
  7. Start your car and check if the error code is gone.

Common Mistakes When Diagnosing the Code P0102

When diagnosing and repairing the P0102 trouble code, it is essential to note some common mistakes people make to avoid making the same mistakes. So what are these?

  • Not checking the vacuum lines and connectors for leaks or damage
  • Not cleaning the MAF sensor before installing a new one
  • Not properly tightening the bolts on the air filter box or not installing it correctly.
  • Not testing the MAF sensor before replacing it.

Code P0102 FAQs

1. Is the code P0102 serious?

Code P0102 is not as severe as any other trouble codes. However, as with all Check Engine Light codes, you should resolve this code as soon as possible to avoid further damage to your vehicle.

2. Is it safe to drive having the code P0102 issue?

The code P0102 should not affect the drivability of your car. However, it is always best to have the issue fixed as soon as possible for safety reasons.

3. Can I fix the code P0102 myself?

In most cases, you can fix a P0102 code yourself. However, there are some instances where you will need to take your car to a mechanic.

4. What diagnostic trouble scanner should I use to scan this error code?

You can use any code reader/scanner to scan this code. However, an advanced one will be better.

5. How much does the code P0102 diagnostic cost?

If the MAF sensor needs to be replaced, the labor will be around $75 to $150 per.


Code P0102 is not a serious issue; however, it is important to diagnose and fix it as soon as possible to avoid any damage to your car. The diagnosis and repair process may seem daunting, but it is quite simple. With the help of a diagnostic scanner tool and a bit of car knowledge, you should be able to fix this code in no time. 

Thanks for reading! We hope this article was helpful. If you have any further questions or comments, feel free to leave them below. Until next time!