Error P0102: troubleshooting the air flow sensor

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Error P0102: troubleshooting the air flow sensor
Error P0102: troubleshooting the air flow sensor

Modern cars are stuffed with all sorts of electronics. On the one hand, this is convenient, since most malfunctions can be determined using the on-board computer, and on the other hand, frightening inscriptions often come out with fault codes in the engine. Error P0102 is a common culprit for failures of VAZ family cars. What this code means and how to fix it, we will tell in the article.

What does error P0102 mean

The operation of the engine is completely subordinate to the commands coming from the car's ECU. By collecting information from different sensors, the controller selects the correct modes for all machine systems. Error code P0102 indicates that the signal coming from the DMRV (mass air flow sensor) has a low voltage. This malfunction can be caused by several reasons:

  1. Excessively clogged air filter. The amount of air entering the engine is not enough for the sensor to work correctly - this is one of the most common reasons.
  2. Proximity of high-voltage ignition wires to the MAF. High voltages in adjacent wires can create self-inductive currents in the sensor and cause incorrect signals to be generated.
  3. DFID pollution.

What is the MAF for

The internal combustion engine runs on a combination of fuel and air. Efficient operation requires a mixture that will burn out in the cylinders almost completely, and for this you need to choose the right ratio.

air flow sensor
air flow sensor

DMRV, otherwise called the MAF sensor, transmits readings to a computer that selects the exact proportion of air and gasoline corresponding to certain crankshaft speeds.

Error symptoms

Undoubtedly, with a P0102 error, the car can continue to drive, but its engine will be unstable.

First, Check Engine lights up on the instrument panel, indicating a problem. In this case, the car may not start well. Instead of steady revs, a cold engine will run erratically and will need to be throttled to keep the engine from stalling.

The error signal may disappear for some time, but later the situation only worsens: failures can occur not only at idle, but also during engine operation under load. For example, during overtaking, when you need to squeeze out the maximum power, the car may start to twitch, not picking up speed. The car may stall on the move as soon as the foot is removed from the gas pedal. All this can lead to an emergency situation onroad.

How to check the sensor

Before you buy a new MAF sensor, you need to make sure that the old one is faulty. First you need to clean the MAF with a special sensor spray. Then see what condition the air filter is in. If necessary, replace. More than half of the time the problem will be fixed.

electrical diagram - description of the operation of the air flow sensor
electrical diagram - description of the operation of the air flow sensor

In order to diagnose the cause of error P0102, do the following:

  1. Erase error code from ECU.
  2. Connect a scanner or trip computer to the OBD-II connector and test drive.
  3. If the error lights up again, then check all potential culprits for its occurrence: filter, connector, wiring harness.

In addition, you need to check the electrical circuit with a multitester and measure the voltage between the contacts of the block.

When the ignition is off, the connector is disconnected from the sensor. Then the ignition is turned on and the voltage is checked between pins 2 - 3, 3 - ground, 3 - 4. Between pins 2 and 3, the voltmeter should show 10 volts, between 3 and 4 - 5 volts, and there should be no voltage between 3 and ground.

Schema Diagnostics
Schema Diagnostics

After checking, you need to install the resistance between pin 5 and ground. In the normal state, it will be 4 - 6 kOhm. If the measurement data does not correspond to the nominal value, then there is either a break or a short in the wiring. Resistance diagnostics are performed with the power off.ignition.

Only after the previous check can it be concluded that the MAF sensor is malfunctioning.

How to make a replacement yourself

The air mass sensor is located between the air filter and the massive air pipe connected to the intake manifold.

After you have established that the VAZ error P0102 pops up due to the DMRV, you can safely go to the store for a new part. A new sensor costs more than 3,000 rubles and is sold complete with a pipe in which it is installed.

Replacement work is done with the ignition off. First you need to disconnect the block with wires from the sensor. To do this, press the bottom of the chip on the latch and carefully remove the connector. In this case, you need to pull not by the wires, but by the block.

Use a screwdriver to loosen the clamp and remove the rubber tube from the sensor. After that, two M6 bolts are unscrewed from both sides of the DMRV.

removal of DMRV
removal of DMRV

After removing the part, you need to look at the markings on the case, because the car industry installs different ECUs on the same models, and it may turn out that a new working sensor will be incompatible with the controller installed on the car.

The sensor is installed in the reverse order of removal. This eliminates error P0102 for Kalina, Priora, Samara - all representatives of the VAZ family with similar injection engines.