P0102 Code – Meaning, Causes, Symptoms (& How To Fix)

P0102 - Mass or Volume Air Flow Circuit Low Input

P0102 Code

Engine trouble codes can be challenging to figure out, especially if the error isn’t something familiar. When dealing with the P0102 code, you might find yourself confused at the different causes. 

In this guide, we discuss what the P0102 trouble code means, so there’s no confusion. We also show you some possible fixes and talk about how much it might cost. 

Code P0102 Definition

P0102 – Mass or Volume Air Flow Circuit Low Input

What Does the P0102 Code Mean?

The P0102 code indicates that the mass airflow (MAF) circuit is reading low voltage. This code sets if the ECM or PCM determines there’s a problem with the performance of the mass airflow sensor, which is found between the throttle body and air filter.

When it’s working as intended, the MAF sends out a signal used by the engine control module to determine how much fuel is needed to mix with the air entering the combustion chamber. If the input or output signal isn’t right or it’s low for a specified amount of time, this code will set. 

The P0102 can often be seen together with the P0100, P0101, P0103 or P0104 trouble codes as they are closely related to the MAF sensor.

P0102 Trouble Code Symptoms

The most common symptom of P0102 is a Check Engine Light. While no other symptoms may occur, there could be performance issues that arise, indicating that something isn’t right. 

Here are the most common symptoms that drivers endure:

Causes of the P0102 Code

Most of the issues surrounding the P0102 trouble code have to do with the MAF sensor itself or the connection to it. However, it’s not uncommon to deal with some sort of leak or electrical short as well. 

Here are the most common symptoms:

How Serious is the P0102 Code?

Low – Usually the P0102 trouble code isn’t stopping you from getting anywhere. In general, it might cause some minor drivability concerns or no symptoms other than the Check Engine Light. You might also notice reduced fuel economy and a rough operation.

If the fault causes you to struggle starting the engine, you may have a more pressing concern. After all, you don’t want to get stranded somewhere.

Either way, the code should be repaired as soon as possible. Otherwise, you could allow further damage to be done as the engine isn’t running in optimal condition. 

What Repairs Can Fix the P0102 Code?

It’s important to complete a full diagnostics check before deciding what needs to be repaired. Otherwise, you could be throwing money at something that won’t resolve the issue. Here are a few of the possible repairs you could be looking at:

  • Repair low voltage, electrical short or wiring harness
  • Clean dirty mass airflow sensor
  • Replace MAF sensor
  • Clean MAF sensor connectors
  • Repair intake manifold air leak
  • Replace air filter

Common P0102 Diagnosis Mistakes

The most common mistake is to replace the MAF sensor without first determining that it is the problem. While the code indicates something is wrong with the MAF sensor, it could be reading faulty because of other conditions.

It’s also possible the MAF sensor simply needs to be cleaned. If it has dirt or corrosion on it, a simple clean up should do the trick. To clean the MAF sensor, remove it and carefully clean the sensor head with some electrical cleaner or a special MAF sensor cleaner and let it dry. This part is very sensitive and you can easily damage it, so do it very carefully and don’t touch it!

How to Diagnose the P0102 Trouble Code

If you want to diagnose P0102 like the professionals do, you would follow the steps we outline. These are the same methods used by certified mechanics when the P0102 trouble code is set in the computer.

  1. Clear all of the trouble codes from the system.
  2. Take the vehicle for a test drive and see what codes set.
  3. Read the new codes and get freeze frame data.
  4. Measure the voltage and ground to the MAF sensor. Inspect the MAF sensor wiring to see if there is anything obviously damaged. Repair wirings if low voltage output from the ECU or bad ground.
  5. Inspect the MAF sensor head, and if you see any dirt or corrosion, you can clean it off carefully with a special MAF cleaner. 
  6. Look for air leaks in the system. 
  7. Check the air filter. If it is dirty, replace it.
  8. Inspect for vacuum leaks by using real-time data.
  9. If no other problems have been found, go ahead and replace the MAF sensor. 

Estimated Cost of Repair

If you plan to have a shop replace the parts, you will need to pay for the components and the labor charge. Here are some estimates on what the repairs might cost you. 

  • Clean dirty mass airflow sensor – $10-$75
  • Replace MAF sensor – $250-$400
  • Repair electrical short or wiring harness – $50-$500
  • Repair intake air leak – $100-$650
  • Replace air filter – $15-$85

Mechanics Tips

Because the MAF sensor is reading the level of air that’s coming in, there’s always the possibility that the air filter is clogged or contaminated, thereby causing an inaccurate reading. This is one of the cheapest solutions, so it should never be overlooked during diagnostics.

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