Replacing the speed sensor VAZ 2107

While the car is moving, the VAZ 2107 speed sensor (injector) generates speed data that enters the electronic engine control unit. Its failure causes errors in injection control and causes a drop in engine power and an increase in fuel consumption. You can check and replace the sensor yourself. To do this, you need a garage with a viewing hole, a flat screwdriver, a 22 key and a multimeter or test lamp.

The principle of operation of the speed sensor VAZ 2107

The operation of the speed sensor is based on the Hall effect, which describes the appearance of electrical impulses when a conductor with a direct current is placed in a magnetic field. The sensor generates pulses when the output shaft of the VAZ 2107 gearbox rotates. During the passage of a kilometer by a car, the VAZ 2107 speed sensor produces about 6000 pulses, the frequency of which allows you to determine the current speed.

Where is the speed sensor VAZ 2107

The sensor is connected to the gearbox on the speedometer cable transmission. To remove and check it, you will need to disconnect the speedometer cable from the gearbox.

Symptoms of a malfunction

The main symptom of problems in the operation of the sensor is the release of the corresponding error code by the on-board computer. Malfunctions can also appear in other signs:

• increased fuel consumption;
• poor engine traction;
• idling or a speedometer working with a large error;
• unstable idle.

Attention! These four symptoms may be caused by problems with other parts of the car.

Causes of sensor malfunction

The design of the sensor is quite reliable. The cause of the malfunction is usually oxidation of the contacts in the sensor or a broken cable from the sensor to the engine ECU.

Contacts must be inspected, if necessary, cleaned and lubricated with Litol. It is better to start looking for a wire break in places close to the plug. There they bend more often, respectively, fray and break. In this case, it is worth checking the grounding of the sensor. The resistance in your network should be around 1 ohm. If no fault is found, check the speed sensor. To do this, it must be pulled out of the car.

How to remove the speed sensor VAZ 2107

To disassemble the speed sensor, perform the following operations:

• install the car above the inspection pit;
• turn on the parking brake;
• put wedges under the wheels;
• unscrew the nut of the speedometer drive cable from the inspection hole with a flat screwdriver;
• disconnect the transmission cable;
• loosen the plastic clamp holding the wiring harness coming from the speed sensor;
• press the spring clips and disconnect the speed sensor unit;
• with a 22 key, unscrew the speedometer drive sensor;
• remove the speed sensor.

The VAZ 2107 speed sensor can be checked with a multimeter or "controller". To install the sensor, follow the above steps in reverse order.

Checking the speed sensor

The easiest way to check the speed sensor is to install a new one in its place. The price of the part is low, so this is the easiest and fastest way to make sure it works or breaks. If there is no new VAZ 2107 speed sensor at hand, then you first need to check the old one, and then go to the store for a new one.

To check the operation of the speed sensor, you will need a small plastic tube with a diameter corresponding to the thickness of the sensor rod, and a voltmeter (multimeter). The check is performed in the following sequence:

• connect a voltmeter to the output of the sensor that supplies electrical signals, and to the "mass" of the car;
• put the tube on the axis of the sensor;
• rotate the tube.

When the tube rotates, the voltage at the output of the sensor should increase in proportion to the speed of rotation. If this does not happen, the VAZ 2107 speed sensor must be replaced.

Tip: In the same way, you can check the speed sensor directly on the machine. To do this, you need to hang out one of the drive wheels, connect a voltmeter to the sensor output and "ground" and start turning the wheels. If voltage and pulses appear, the sensor is OK.

Instead of a voltmeter, you can use a test lamp. In this case, when checking the performance, it is necessary to apply voltage to the "positive" output of the speed sensor. If the lamp flashes when the sensor is rotated, the problem is not with the sensor. You will have to check other components and parts of the "seven", which may affect the operation of the engine ECU.