Air & Fuel Mixture ControlOBD2 Codes

P0102 – Meaning, Causes, Symptoms, & Fixes

Code P0102 Definition

Mass or Circuit Airflow (MAF) Circuit Low Voltage Input

What Does P0102 Mean?

The Mass Airflow (MAF) sensor measures the amount of air entering the engine. When code P0102 is set, there is a low voltage output to the ECM, PCM, or ECU depending on your car type (check your owner’s manual for your specific car).

P0102 Symptoms

  • Check Engine Light
  • Less power to the engine
  • Low fuel consumption – causing engine damage

P0102 Causes

  • Dirty air filter
  • Faulty MAF sensor
  • Corroded/Damaged MAF circuit terminals
  • Carbon covered MAF sensor screens

Code P0102 Severity – Low


Code P0102 does not pose any serious danger to the driver or the vehicle and there are no drivability issues that may occur. However as the case with all Check Engine Light codes, it should be fixed as soon as possible to prevent any further damage to your vehicle.

Code P0102 Common Diagnosis Mistakes

Replacing the air filter without further inspection of the MAF sensor circuitry and MAF sensor itself.

P0102 Diagnosis

  • Tools Needed to Diagnose:

Difficulty of Diagnosis and Repair – (1-4)

  1. Clear your Check Engine Light using your FIXD sensor and do a road test to see if your Check Engine Light comes back on (~20-50 miles should be a range).
  2. Check your air filter and replace if needed.
  3. Clean your MAF sensor to make sure that there are no pieces in the system that do not belong. Check out this video for a visual step by step walk through.
  4. The quickest way to check if your Mass Air Flow (MAF) sensor is the problem is to disconnect your electrical harness while your car is running. Check your owner’s manual to locate the MAF sensor for your specific car.
    1. NOTE: Make sure that all other parts of your vehicle have cooled down (6-8 hours inactive) before doing this test. Reference this video for visual reference
    2. If your car’s engine shuts off, your MAF sensor is operating normally. If it does not shut off it means that your MAF sensor is not operating normally and should be replaced.
  5. If these steps do not clear your Check Engine Light, you may need to visit a mechanic because there may be electrical issues.

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  1. This is a shade tree mechanics best friend when it comes to diagnosing the cause of the check engine light.

  2. mine is a 2000 F150 5.4 custom 1956 IH, COE with a Ron Francis wiring harness. this tool is giving me hope for a engine light FIX.
    Very interesting. and Thanks for your fallow up.

    1. This was very helpful. I followed the instructions and learned that the maf needs to be replaced

      1. Awesome to hear, Thomas! 🙂

  3. FIX continues to evolve in all the right directions. I love the follow up explanations and suggestions. It’s so much more than a code reader!

    1. Thank you so much Kim! We appreciate it!

      FIXD Team

    2. On my mad I unplugged to put the top cover on the relay cover and forget to plug it. Back up lol

  4. I do you like this webpage it does help a lot by understanding what is the issue with my car without going to a mechanic right away and then to find out it’s something as simple as a sensor that I can replace myself thanks for having this page helps a lot

  5. Basically needed to state I am thankful that i came on the site!

  6. I have been using my FIXD sensor for 3 months now, and its saved me alot of money haha

  7. My 2008 Ford Focus will idle but very rough when I unplug the MAF sensor. It will also backfire but it will continue to run. I thought the vehicle should shutoff with the MAF sensor unplugged. I replaced the MAF sensor and also replaced the Idle Position Sensor and Crank Sensor. A side note is the Serpentine Belt is still off the vehicle so not sure if that anything to do with my issue. Error Codes are P0113, P0122, P0102. Thanks in advance for any helpful advice.

  8. My engine light come on and turns off on it’s own but it keeps throwing that code I don’t know it is completely that. Does anyone else have a suggestion?

  9. Went to pep boys and showed the parts manger my fixd app and he knew i knew what i was talking about

    1. So glad to hear it, Thomas! Thank you so much for the kind words and for using FIXD!

  10. First of all, I”d like to say thank you to FIXD for having this forum. I don’t know if we all can get our questions answered but I think it’s worth trying. So, here’s the problem with my ’05 Subaru Forester X. It throws PO102 code and I quickly replaced the sensor but it didn’t fix it..instead it throws another code PO112. So, now it has 2 codes. Well, I put the old sensor back on and tested it again to see if the sensor would give me the same codes. But no, the old sensor still throws only po102 code. I’m really confused what’s going on here. The connector is not an original connector (the original broke) I replaced it with cheap one from eBay, maybe this is why it’s giving me the code(s). Any other ideas guys? Thank you.

  11. Will a bad mass airflow sensor cause car not to turn over

    1. Hey Cedric, a faulty MAF sensor can prevent the engine from firing and starting, but not cranking. Here’s an article about the MAF and how to clean it that may be helpful:

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