The mass air flow (MAF) sensor is an air flow meter that measures the amount of air entering the engine. The powertrain control module (PCM) uses the MAF sensor signal in order to provide the correct fuel delivery for a wide range of engine speeds and loads. A small quantity of air entering the engine indicates deceleration or idle.

A large quantity of air entering the engine indicates an acceleration or high load situation. The MAF sensor has an ignition 1 voltage circuit, a ground circuit and a signal circuit. The PCM applies a voltage to the sensor on the signal circuit. The sensor uses the voltage in order to produce a frequency based on inlet air flow through the sensor bore. The PCM uses the barometric pressure, air density, manifold pressure, throttle position, and the engine RPM in order to calculate a predicted MAF value. The PCM compares the actual MAF sensor signal to the predicted MAF value in order to determine if the signal is stuck based on a lack of variation, or is too low or too high for a given operating condition. DTC P0101 will set if the actual MAF sensor signal is not within a predetermined range of the calculated MAF value.
Possible causes for this code are:

  • Faulty sensor
  • Broken wires at the sensor connector. Tug on each to see if it stretches or breaks
  • Loose air intake duct or breather hose / tube between the MAF sensor and the engine
  • Dirty sensor. Try spraying cleaner inside the sensor, then take for drive to "Blow out" the cleaner

Related Auto Repair and Information

Related Automotive Information


    • Guest - Andrew

      Hi I got p0101 code in a Nissan sentra I wonder what it is

    • Guest - Matt

      In reply to: Guest - Andrew

      Like this article states- sounds like you have a mass air sensor problem. You can try cleaning it, but that usually does not work. If the wiring is OK, You would have to have it replaced.

    • Guest - JIM

      I'm getting p0101 and p0131 constantly on my 2000 grand am. I seem to be lacking power sometimes, and I've had it twice now where I have no power in overdrive. I litterly have to floor it and get into passing gear to get my car to accelerate. I already changed the EGR cause I had that one coming up too. But the problem is still there

    • Guest - Frank

      In reply to: Guest - JIM

      Sound like a plugged catalytic converter. That would also be the cause of your EGR valve code.

    • Guest - gopinathan

      Sir, I own a Matiz 1999 model.My mechanic carried out engine reboring after observing heavy smoke through exhaust pipe. After reboring, the engine starts normally, but when we accelerate the engine, the fuel flow is getting chocked and the engine is not picking up .

    • Guest - Tech

      In reply to: Guest - gopinathan

      Hard to say. But sounds like your mechanic did not do something correctly. Timing could be off, bore too large, rings not seating, etc.


    Latest Articles

    Buick Century radio code 2001

    I can get the first 3 numbers by pressing the 2&3 button, however I cant get a second set of ...

    1999 Dodge Neon

    Extremely hard to turn steering wheel p/s fluid full no visible leaks or damage to the ...

    Power steering hard to turn

    Extremely hard to turn steering wheel p/sl fluid full no visible leaks or damage to the ...

    2004 jeep liberty front ...

    I replaced my front drive shaft again and took it for test drive and it snapped again. Started ...

    2001 Tahoe Sounds Like A ...

    Just bought a 01 Tahoe seemed to run quiet at first then after a while when u first start it it ...

    Log In Or Register
    ? The Benefits

    How Things Work

    Windshield Wiper System Operation

    The windshield wiper motor module is part of the windshield wiper motor cover and controls wiper motor operation. The accessory voltage supply circuit to the windshield wiper motor assembly is used to operate the wiper motor in all modes. The windshield wiper motor is a 2 speed motor and is operated at low speed in all modes except HIGH.

    Read more...

    Common Engine Codes

    Evaporative Emissions Leak Code P0440 - P0455

    P0440 - P0455
    The control module tests the evaporative emission (EVAP) system for a large leak. The control module monitors the fuel tank pressure (FTP) sensor signal to determine the EVAP system vacuum level. When the conditions for running are met, the control module commands the EVAP canister purge valve OPEN and the EVAP vent valve CLOSED .

    Read more...