P0102 diagnostic trouble code (DTC): Mass Airflow (MAF) sensor

The engine needs clean air in the right quantity just as much as it needs fuel. The average ratio of oxygen to gasoline is 14.5:1. Hence, somehow this parameter needs to be controlled. That is what the mass airflow sensor does. Otherwise, we will get an engine malfunction, and code P0102 will appear on the scanner screen.

DTC P0102. Symptoms


p0102 scanner

“Air flow sensor input low” – this is the most common decoding in OBDII code descriptions. Along with error P0102, codes P0100 – P0104 inclusive can also occur.

MAF sensor from Volkswagen Golf 5 engine.

The error makes itself felt mainly on Chevrolet engines (Lacetti, Aveo, Cruze, Captiva), Japanese Mazda MPV, as well as is often found on the injector cars Dacia, Renault, Nissan.

датчик дпдз ваз 2110
And this is the Dacia Logan sensor, installed right after the air filter.

Where the MAF sensor is installed 


The vast majority of mass airflow sensors are installed in the intake line behind the air filter. 

дмрв фольксваген гольф
The same sensor was installed on the Golf V engine.

This is important because the cleanliness of the filter greatly affects the performance of the MAF (Mass Air Flow Sensor).

The installation location is different for each individual engine, but it is not difficult to find if desired. 

The task of the sensor is to accurately measure not only the volume, but also the density of the air used to prepare the working mixture. The MAF data is fed to the electronic control unit and the fuel injection quantity is calculated based on it.

воздушный фильтр шевроле
The air filter is frequently forgotten. At the same time, it is one of the main causes of MAF sensor failure.

What does fault code P0102 mean, symptoms of malfunction


The ECU signals an error when it has suspicions about the sensor performance. Namely, the actual pulse of the MAF does not agree with the nominal values in real conditions under a particular load.

In some engines (Toyota, BMW, Jaguar, Chery) the MAF sensor also measures the air temperature for more accurate fuel calculation.

The main symptoms that confirm the correct diagnosis of the self-diagnostic system are as follows:

  1. Black smoke from the exhaust pipe also indicates either a rich mixture or worn spark plugs.
  2. Check Engine message appears on the dashboard.
  3. Unstable idle rpm.
  4. Power decrease.
  5. Increase of fuel consumption.
  6. Difficult starting, engine stalls after starting both cold and hot.

Other unpleasant symptoms like engine overheating, flooded spark plugs are not excluded.

Potential causes of diagnostic trouble code (DTC) P0102


All causes of this DTC are somehow related to the mass airflow sensor. And that could be:

  • contamination of the sensor, the most common;
  • MAF sensor is out of order, replacement only;
  • faulty wiring, short circuit or breakage;
  • corrosion of contacts on the socket or on the sensor itself.
контакты дмрв
Clean the contacts on the terminal and on the sensor itself – necessarily.

Here it is important to understand that a single error P0102 tells unambiguously about the failure of the sensors, and its appearance on the background of errors associated with lambda sensor (oxygen sensors) or ignition skips significantly complicates the diagnosis.

How to check the airflow sensor, DTC P0102 diagnosis


Perhaps you should start with a simple one, gradually going deeper into the control system, if at some point the error does not disappear:

  1. Check the wiring. Carefully examine the wires and check them for insulation damage, shorts, or breaks.
  2. Make sure the sensor harness is not near any high voltage wires or ignition coils. This creates interference and affects the MAF signal pulse.
  3. Thoroughly clean the contact pads of the wiring harness and contacts of the MAF air flow sensor. No oil, traces of antifreeze, dirt and dust should be there at all.
  4. Check the air filter. A clogged filter is a frequent cause of P0102 error. If the filter has not been changed for a long time, change it.


  1. Getting to the sensor. Some MAF sensors have an intake grid. It can also be clogged. If this is the case, clean it carefully.
    приемная сетка
  2. Clean the sensitive elements of the sensor. You have to be extremely careful here, because they are very sensitive to corrosive liquids. 
    датчик MAF

It is absolutely inadmissible to clean the DMV with anything you can get your hands on – WD-40, carbcleaners, liquid wrenches – all this does not work.

Be careful!
It is important to know that not every air flow sensor can be cleaned and washed. They come in film type and wire type sensors. It is highly undesirable to clean film type sensors, otherwise there is a risk of not starting the engine at all.
maf sensor
Sensor location: 1 – air filter; 2 – MAF sensor; 3 – engine.
конструкция датчика
Air flow sensor construction: 1 – body; 2 – filter-grid; 3 – connector; 4 – temperature sensor; 5 – main piezo element.

How to clean the MAF sensor


Consequently, the sensor can be destroyed by an aggressive liquid in no time at all. It costs a lot. For example, a MAF sensor for a Chevrolet Aveo will cost $85 to $100, and the same sensor for a Ford Focus or Mazda6, MPV, CX, VAG cars from $80 to $120.

Also, if the sensor has already been repaired or cleaned repeatedly, it is useless to play with it. Most likely, the active sensing elements have worn out.

Never use brushes, ear wands, matches, pins or other nonsense to clean the sensor. It is guaranteed to ruin the sensor. As well as liquids containing acetone and other solvents.

Of improvised means at your own risk, you can try available cleaners:

  1. Alcohols (ethyl, methyl, isopropyl). Apply to the sensor carefully, spraying through a medical syringe with a needle.
  2. Ant alcohol. Best used for non-sensitive surfaces.
  3. Aqueous solutions of glycerin (detergents, liquid powders, soap). Doubtful method, but if nothing else, you can try. A thorough drying after washing is necessary.
очиститель датчика
There are a lot of different compositions for cleaning the MAF sensor on the market. Some of them are fakes. Here it is clear where the original is. The danger is that most of the cheap stuff contains acetone. Which ruins the sensitive element of the sensor.

EGR valve and error P0102? It’s quite possible.


This case is not so common, but it does occur in practice. Even when the EGR valve (exhaust gas recirculation, more about it here) shows no signs of malfunction, it can affect the mass airflow sensor as well.

egr system

The situation can develop in two directions:

  1. The valve hangs open or does not close completely. In this case, the intake tract receives excessive exhaust gases. And they contain unburned fuel and oil. But that’s half the trouble. The MAF will take into account much less fresh air than it actually has, which will affect the working mixture proportions.
  2. The valve is permanently closed or clogged with soot. In this case, much more air enters the cylinders than the ECU calculates when preparing the mixture.

We already know what to do about it. Consequently, the EGR valve should not be overlooked when the DTC P0102 occurs.

Special products for MAF sensor cleaning


Of course, in order to kill an expensive sensor without any risk, you should wash it with a special cleaner. The price of such sprays ranges from $3 to $12, and one 350-400 ml bottle is enough for 5-6 cleanings.

Liqui Moly Luftmassensensor Reiniger


It’s on sale most of the time, so there are plenty of fakes on the shelves, and especially in online stores. It cleans perfectly, evaporates quickly and leaves no traces on the surface. It does not require any treatment after use.

Johnsen’s 4721 Mass Air Flow Sensor Cleaner


The cleaning procedure is also safe because the cleaner does not even damage the plastic. There is no need to worry, it can also be used as a cleaner for electronics components. It cleans the surface of MAF sensors in seconds, removing all kinds of contaminants.

Gunk MAS6 Mass Air Flow Sensor Cleaner


A good cleaner, but a bit expensive. But it copes not only with a plaque on the working organ of the sensor, but also with grease, dust and other deposits. A 170-gram canister is enough for 4-5 times. In addition, the spray can be used for effective contact cleaning.

Penray 2520 Mass Air Flow Sensor Cleaner

Penray 2520 Mass Air Flow Sensor Cleaner

Practice has shown that this spray performs a deep cleaning of the sensor. There is one “but” – the liquid dries about 20-30 minutes, which indicates the presence of heavy substances in its composition. No side effects on the sensor have been identified, though. Inexpensive and effective cleaner. 

Of course, there are other compositions on sale, but these are the ones recommended by practicing masters.

When to clean MAF sensor, durability


On average, the mass airflow sensor will be able to run no more than 120-160 thousand km. After this mark, cleaning, purging and persuasion have no effect on it. Only replacement. As preventive steps, we can advise only trivial replacement of the air filter as it gets dirty.

очистка датчика

The condition of the engine also affects the life of the sensor, because evaporation, oil, and fuel splashes are clearly not good for the sensitive element of the mass airflow sensor of any type.

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