Code P0102: Now What?

Your diagnostic tool has pulled up a code P0102 and you aren’t sure what to do. That’s okay. We have all been there at one time or another. That’s the reason we put these guides together. To help those who are new to the industry learn specific codes and how to fix them on your own. 

Today we’ll chat about code P0102, which seems rather important when you look at its sequence in numbering. Where an issue lies in code numbers has nothing to do with the severity, as you will soon see. 

Code P0102

If you were to look up this code in a manual it would say Mass or Circuit Air Flow Circuit Low Voltage Input, but that doesn’t explain much does it? What that means is the Mass Air Flow Sensor, which measures the air that the system takes in, may have a low voltage output to the ECM, PCM, or ECU. The destination depends on the type of car you are working on. 

Mass Air Flow Sensor (MAF)

Check air flow meter automobile engine by car technician.

Without this, the electric fuel injection system in your engine would not work. You can find it between the air filter and the intake manifold. It does exactly what the name indicates, it measures the airflow into the engine

There are only a few airflow sensors but contemporary engines use a kind called hot-wire, which works with a small wire that’s heated electrically, which doesn’t take much of a current to achieve. Air cools it down which, in turn, prompts it to get more electrical current so it will remain hot. 

Besides reading a code on the diagnostic tool you use there are other ways to know that the MAF might have a low voltage input. 

  • Your check engine light should go on
  • You will feel less power going to the engine
  • Your engine will consume less fuel, which can cause damage
  • Your car could have an inconsistent idle

Is It Important?

Check engine light. Car dashboard in closeup

This issue isn’t anything to worry about. No one is in danger while driving or riding in the car and you shouldn’t have any issues while driving. But, as we say in all of our pieces, the check engine light is not to be ignored. The sooner you find out what the problem is and fix it the more money you will ultimately save by saving your engine from damage. 

Getting To The Root Of It

There are several reasons why your MAF is getting a low voltage input. It could be any of the following reasons. 

  • The MAF sensor could be defective
  • The MAF circuit terminals could be eroded or run-down
  • The MAF sensor screens could be covered in carbon
  • The air filter could be dirty or clogged
  • PCM issues

How To Find The Problem

Even though the damage this type of issue can cause is minimal it takes specific tools and a level of expertise to sniff out the root cause. Here is how a professional would complete the job. 

Step One

Using an OBD- II scan tool, a qualified user can indicate if the engine is diagnosed with P0102. To do that they need to reset the fault codes in the scan tools 

Step Two

Driving car during low visibility at night

Next, take the car on a road test to see if the code comes up again. If it does then it’s time to open the hood. 

Step Three

Inspect the electrical connectors, the sensor’s wiring and other components, the air cleaner, the air filter, and the MAF unit for damage. If you can’t find anything then it is time to contact a professional to conduct a circuit test with a multimeter. This will determine if the output is truly low or is there another issue. 

Things To Look Out For

When we see an error code on our diagnostic tool, more often than not it’s because we weren’t following the right protocol. It’s important to know your equipment. If you indicate that the MAF sensor is faulty try cleaning it with a specialized cleaner before buying a new one. 

How To Fix It

Depending on what you uncovered during your investigation, there are several ways you can fix that P0102 code. But it is important to remember that there is never one solution for a P0102 code or any other code for that matter. Here are some possible solutions.

Cropped view auto mechanic with mud on hands fixing automobile.
  • Check the electrical connector to make sure it hasn’t lost connection. If it has, reconnect it. 
  • If wiring is corroded or damaged then replace it
  • If you find any vacuum leaks have them fixed

The Cost Of Repair

It may seem redundant because our answer to this question is typically the same for every code or car issue. Just as there isn’t one way to fix all the problems that can arise, there are variations in cost that can only be determined after the problem is revealed. That’s when you can figure out parts and labor if you aren’t doing the work yourself. 


Mechanic and car repairing in garage

A P0102 code is not that serious but, if you see it then you shouldn’t put it off or ignore it. Car issues never go away and, like most things in life, an engine is completely connected. One small problem that doesn’t get the attention it needs can easily branch out into a myriad of motor issues that will end up costing an arm and a leg to repair. 

We always recommend consulting professionals before setting out to do any mechanic work you are unfamiliar with for your safety and the longevity of your engine. If you found this article helpful let us know in the comments section below. You can also share this with your auto-loving friends or groups.

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