Why does the speedometer on the VAZ 2112 not work? Some repair tips

When the speedometer does not work on a VAZ-2112 hatchback, the reasons may be different. Usually they try to repair the tidy, but the speed sensor turns out to be faulty. The ECU detects a malfunction of this sensor with difficulty, and the CHECK lamp does not turn on. The fact that the speed sensor is broken has to be identified by the following signs: idle speed always remains low, and the engine stalls when changing gears. These nuances will be discussed in more detail below, but we will only talk about 16-valve valves.

If all devices do not work, then one fuse is at fault. The video shows which one.

Why does the speedometer on the VAZ 2112 not work? Some repair tips

Along with serious breakdowns, smaller but no less unpleasant ones also occur, for example, the speedometer on a VAZ 2112 does not work
. In this article we will try to analyze this common problem in detail. Typically, car enthusiasts consider a speedometer to be a device in the dashboard that shows driving speed and mileage. In fact, these functions are performed by two devices. The number of kilometers traveled, that is, the mileage is counted by the odometer, and the speed of movement is directly determined by the speedometer.

On first generation cars

The odometer was mechanical, and worked by transmitting torque by a gear mounted on the secondary shaft of the gearbox through a cable to the odometer. The most common malfunction of this mechanism was a broken cable.

Such a breakdown is very easy to diagnose: when the cable begins to break, you can very clearly hear how the steel wire touches the “jacket” from the inside. The cause of rapid wear was the sharp bend angles of the cable during installation.

The speedometer on the second generation VAZ 2112 does not work for more complex reasons. As you know, after the model was improved, both the speedometer and odometer became electronic. The principle of their operation is to read and transmit information by a speed sensor installed in the gearbox housing directly to the instrument panel.

It is logical to assume that possible malfunctions should be looked for only in these places. However, there is a nuance here: AvtoVAZ does not produce separate spare parts for the dashboard, so in the event of a breakdown you will have to buy the panel assembled.

Incorrect operation of the speedometer can be displayed on the dashboard in different ways; the needle may simply not move, as if the ignition is turned off; sometimes, on the contrary, it may show excessive speed. The simplest and most common cause of failure is contact oxidation.

. Everything is simple here, anyone can visually notice the oxide; just clean them and put them back.

If the contacts are in order, you need to check whether voltage is supplied to the speed sensor itself. A tester is useful for this; if you don’t have one, you can use an ordinary car light bulb with two wires connected to it.

Do not forget that the wires from the sensor to the instrument panel go through the mounting block, therefore, the cause of the malfunction may be hidden in it. Considering the fact that most car enthusiasts have a rather mediocre understanding of auto electrics and electronics, you should think about visiting a specialist. If electricity is supplied to the contacts, the conclusion suggests itself - change the speed sensor.

The procedure for replacing the sensor is very simple and does not require any special knowledge or effort. You only need a key “for 22”, and just in case, “for 10”. It’s more convenient to get to the sensor from under the hood; you don’t even need a hole.

One mechanical nuance often arises here

, which is the reason why the speedometer on the VAZ 2112 does not work, the rod may simply break off, and in this case, removing the speedometer drive cannot be avoided. Then the “10” key will come in handy, but you need to remove the rod very carefully; if it falls into the gearbox housing, a completely different story will begin.

When installing the speedometer drive rod in place, do not forget to lubricate the rubber O-ring. All that remains is to connect the wires and check the operation of the speedometer.

Expert recommendations

Driving with a faulty speedometer poses a danger both to others and to the car owner himself. When a problem is discovered, it should be corrected immediately. If the driver himself is unable to do this, he will have to take the car for repair to a specialized service center or service station.

But most problems are fairly easy to repair with your own hands. If suddenly the speedometer no longer displays the correct data, then you should not panic.

It usually happens that the breakdown consists of faulty wiring, oxidation of contacts and other easily correctable disturbances in the transmission of electrical signals. It is not difficult to detect such a breakdown; it is enough to carry out a visual inspection, during which the cause of the malfunction will immediately become obvious. Then you can fix the breakdown on the VAZ 2110 with your own hands - it won’t be difficult.

Contamination of the controller can also cause a malfunction. You need to remove it and clean it, and then install it back. Often this procedure is enough to make repairs when the speedometer on a VAZ 2110 car stops working.

The proper operation of the speedometer is important while driving, and many repair methods are simple and accessible to most drivers

Therefore, you should not delay the diagnosis and repair of this important device.

Useful video:

Why the speedometer does not work on a VAZ-2112: the main reasons for a 16 valve engine

If all devices do not work, then one fuse is at fault. The video shows which one.

Electrical diagram

The sensor itself is powered by a voltage of 12 Volts (pink-black cord), and another pin is connected to ground. The gray wire is the sensor output. It is connected to the voltage source through a resistor (see figure).

Typical connection diagram for DS on a VAZ-2112

The diagram shows that the output is connected to the ECU terminal. Terminal number:

9 – block January 5.1, also BOSCH M1.5.4N (engine 21120, 1.5 l);
59 – BOSCH M7.9.7 module (ICE 21124, 1.6 l).

Another gray cord goes to the “red” block on the dashboard, where it connects to terminal 9.

As you can see, everything is elementary.

Instrument panel test on video (speedometer self-diagnosis)

There are some things we don't specifically consider.

Power to the circuit shown in the previous chapter comes from main relay 6. It is also called the “ignition relay”. There is also fuse 1 in the circuit.

Additional relay and fuse box

When the ignition circuit is broken, both the speedometer and the ECU module do not work on the VAZ-2112, and the engine does not start at all. So advice about checking the relay would seem stupid.

Advice for those who have an oscilloscope

If you still decide to dismantle the sensor, connect a 1 kOhm resistor to its output (to the middle terminal). The resistor tap is connected to the “plus” of the power supply. By turning the shaft by hand, pulses can be observed at terminal 2. There are six pulses per revolution.

Mechanics

The following diagram shows exactly how the speed sensor is designed.

Speed sensor for VAZ-2112

2110-3843010-13 – sensor;
2110-3843010-18 – sensor;
2108-3802820-10 – speedometer drive;
2101-3802718 - pad;
2108-3802822 – drive housing;
2108-3802830 - sealing ring;
2108-3802834-20 – driven gear;
2108-3802833-20 – drive gear;
2101-3802717 - washer;
15896211 – M6 nut;
12601271 – wavy washer;
11500121 – pin M6x14.

Elements 1 and 2 are interchangeable.

Dismantling

To remove the sensor from the car, you need to disconnect its connector. The sensor housing is fixed near the CV joint - the desired point is shown by an arrow.

First step in dismantling

When the connector is disconnected, take a flat key “22” and unscrew the plastic nut. Then you can change the sensor or repair it.

What you need here is a flat key

To replace the sensor drive, use a “10” key to unscrew the M6 nut and remove it together with the washer. The drive housing is rocked from side to side - you need a 14mm spanner.

Installation requirements: on the one hand, it is necessary to obtain a tight seal, on the other hand, the plastic must not be broken.

Dashboard connectors and speedometer contacts

The dashboard, as well as the speedometer on the VAZ-2112, may not work when they are disconnected from ground or power. Be aware that the speedometer receives power separately from the instrument panel. This also applies to the “mass”. Wiring:

X2-2 : +12V to the speedometer;
X2-3 : speedometer “mass”;
X1-9, X1-10 : power supply for tidy;
X1-1 : “mass” of the tidy.

Connector X2 is painted red, X1 – white. Terminals 8 and 9 in connector X2 are the speedometer output and input. The output is connected to the on-board computer.

Both terminals (X1-9 and X2-2) are connected to one wire - orange. This line is protected by a fuse installed in the main mounting block (F19).

How to remove the tidy

First, disconnect the negative terminal of the battery. Then use a screwdriver to unscrew the 4 screws (photos 1 and 2) to remove the frame with glass.

Removing the dashboard

In the second step, unscrew the two screws holding the dashboard in place (photo 3). Next, compress the petal brackets to remove the tidy completely.

If you connect the battery and turn on the ignition, the orange cord (connectors X1 and X2) should receive voltage “+12”;
The presence of “ground” at terminal X2-2 is also a very important indicator;
The gray cord (terminal X2-9) is usually called “+12”, and in rare cases - “ground”. When moving, pulses should appear at this terminal.

Symptoms

When the VAZ-2112 speedometer does not work, the car owner is faced with a number of symptoms that manifest themselves in the performance of the engine. The operation of the injection system requires the simultaneous combination of almost all electronic sensors in the circuit. The ECU calculates the mixture and fuel supply based on many data coming from the electronic components of the machine. Symptoms of a non-working speedometer are as follows:

Notification of on-board computer errors P0501 - P0503. These errors indicate an increase or decrease in the power of the pulses emanating from the EMF.
A "Check Engine" alert often comes with these codes. The reason is an incorrect calculation based on incoming signals from the EMF.
Partial or complete stoppage of the speed meter needle.
Problems when starting a cold power unit.
Noticeable loss of power.
The power unit is unstable, especially when accelerating or shifting into gear.
There is a noticeable increase in fuel consumption.

If clear signals from the speedometer sensor are lost, the on-board computer incorrectly calculates the required amount of fuel and the proportion of air in it. For this reason, speed stability decreases, consumption increases, and a significant part of the power and dynamics is lost. If the described symptoms appear, the owner can independently diagnose all components of the speed calculation using the instructions below.

Why the speedometer does not work on VAZ 2110, 2111, 2112

The instrument cluster is an integral part of any car, so it is so important that all its readings are correct. One of the common problems of the dashboard is a malfunction of the speedometer (the speedometer needle jumps or lies at zero). Do you know what could be the reasons for this trouble?

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4. If the speed sensor is working, then check the operation of the gearbox drive. We remove the sensor, cover the drive with our fingers or insert a 5 cm long stick and push the car forward or backward a little. 5. Malfunction of the instrument panel. Replace the device with one you know is working, this will be the fastest way to check its serviceability. If this is the problem, you can try to repair it. 6. If you notice that the speedometer has failed after disassembling the dashboard, then perhaps the reason is simple - the speedometer needle is touching the trim. In this case, simply lift the arrow a little using a fork (see tuning the instrument panel). 7. If the speedometer does not work after checking all six points and the Check Engine light is on, then it makes sense to diagnose the car.

Have you encountered a non-working speedometer on a VAZ? What was the reason in your case? How did you solve the problem? Let us remind you that other tips and recommendations for the operation and repair of VAZ can be found in this category.

Why didn't the speedometer work on your VAZ car?

Signs of device failure

The fact that there is trouble with the speedometer is evidenced, first of all, by the immobility of its needle while the car is moving. In this situation, the driver must immediately proceed (with all precautions) to a service station or garage.

You should suspect that the device is not working when the arrow:

begins to fluctuate sharply;
freezes periodically;
shows the speed while the engine is warming up, and stops as soon as it starts moving.

In all cases, it is important to find the causes of the breakdown.

The speedometer on the VAZ-2112 16 valves does not work

Purpose and principle of operation of the speedometer

The car speed meter kit consists of a speed sensor (DS), connecting wires, a mains fuse and an indicating device. On the “tens”, a dial speedometer is installed. It is located on the dashboard and is made in a single unit with other instruments and indicators. When the car is moving, the speedometer needle shows the true speed, and the odometer records the distance traveled. Readings are displayed either on the LCD display or on the drum counter.

On VAZ-2110 cars of the first production, a mechanical speedometer drive was used, made in the form of a cable in a metal braid with tetrahedrons on both sides. For fastening to the device and the drive device there were special union nuts. The torque from the secondary shaft of the gearbox was transmitted directly to the indicating device via a cable.

The VAZ-2110 electronic speedometer is installed on models with injection engines.

The operating principle of the device is based on the Hall effect. The signal from the DS is transmitted to the electronic control unit (ECU) and, converted, enters the input of the speedometer circuit. In addition, it is involved in the ignition system and fuel supply to the injectors. DS is an asynchronous generator excited by permanent magnets. The signal enters the ECU in the form of electrical impulses proportional to the speed of the vehicle. For example, while a car travels a distance of 1 km, about 6 thousand of them enter the control unit.

Signs and causes of DS problems

VAZ “tens” are equipped with pointer indicating devices, i.e. the speed is judged by the angle of its deflection. If, while driving, the speedometer needle jumps and jumps, lies at “zero” or shows values that do not correspond to the true ones, and the odometer does not record the distance traveled, then this indicates a breakdown of the DS.

This situation occurs due to contamination of the sensor contact block, since the primary device is located on the gearbox housing under the hood and is not protected from dirt. The pad may be exposed to oil vapors penetrating through damaged seals. This leads to loss of contact and, as a result, incorrect speedometer readings. Such a breakdown can occur both with sensors with a square connector and with a round one. The difference between them is that the former are used in Bosh systems, and the latter in January 4 and GM.

When the speed sensor fails, unstable engine idling is often observed, and fuel consumption also increases. In this case, the DS is replaced. When choosing a working sensor, it is advisable to choose a model that is identical to the old one. Preference is given to products whose pinouts are indicated in the form of “-”, “A” and “+” rather than a digital designation. This will help when repairing the device and measuring the output signal.

The DS drive rod must be metal, not plastic. Otherwise, the service life will be no more than six months. When purchasing a working device, check that it is complete, that there are no backlashes, and that there is a washer on the rod. Replacing the DS is carried out independently and does not cause any difficulties.

DIY replacement instructions

Now let's take a look at the procedure for replacing the device. Before replacing, you need to buy a new sensor. It is best to purchase a DC with a metal rod - such devices are considered more reliable and usually work much longer. There is nothing complicated about the replacement; the procedure is described in detail below (video published by user Inzil Nazmutdinov).

Speedometer Troubleshooting Options

Failure of the speed sensor is not the only reason for the lack of speedometer readings. The performance of the latter can be affected by a break in the connecting wires or a lack of contact in the terminal block, as well as a breakdown of the indicating device. If, when checking the DS, it turns out to be serviceable, then the search for the defect continues from the block to the speedometer. To ensure the integrity of the line and check the device for functionality, you need to use a test lamp.

To do this, one control wire is connected to the negative terminal of the battery and the ignition is turned on, and the other wire is often touched to contact “A” of the block, creating a kind of impulse. In this case, the speedometer needle should deviate from its original position. If the effect is achieved, then this section of the kit is serviceable, otherwise they begin checking the integrity of the circuit from the block to the fuse and then to the device. If the result is negative, we can talk about a device malfunction.

Replacing the speedometer is carried out with the instrument panel, since the industry does not produce spare parts for its repair. According to statistics, only in 7% of such malfunctions the inoperative element is the indicating device. If the speedometer kit is operational, but signs of malfunction remain, then most likely the drive gear located in the gearbox has broken down. It is recommended that such repairs be carried out at a service station, since it is necessary to dismantle the gearbox and disassemble it.

On the “dozens” of the first releases, speedometer problems can arise as a result of a broken drive cable or if the edges of the tip are “licked”. In this case, the cable is dismantled and replaced with a working one. If the speedometer drive socket is damaged, it must also be replaced.

Speedometer does not work on VAZ 2110-2112

If suddenly the electronic speedometer on your VAZ 2110 - 2112 car refuses to work: - the speedometer needle falls or jumps, regardless of the speed, - the speedometer needle freezes, - the mileage is not counted, - when the engine warms up, the speedometer needle freezes in one place and does not move – the speedometer “lies” in the speed and mileage readings and fuel consumption has increased – the car stalls and the “CHECK ENGINE” icon lights up on the dashboard – errors P-0501, P-0501 or P-0503 are displayed on the on-board computer or during diagnostics.

These are direct indicators of a malfunction of the car's electronic speedometer. This problem is common and completely solvable. Most often, the main reasons why a car's speedometer fails are: breakdown of the speed sensor, break or short circuit of the electrical circuit wires, lack of contact in the speed sensor (DS) plug, oiling or contamination of the sensor if oil from the gearbox (gearbox) gets on it. or contamination due to oil leakage through the engine valve cover, the speedometer drive gears located inside the gearbox have broken.

To fix a speedometer breakdown, you need to find the cause of its occurrence. The speedometer may not work due to a blown fuse F19 (10A) located in the fuse box. If the fuse is in order, then the first thing you need to do is check all the contacts and, if necessary, clean them of dirt. Oxidation of electrical circuit contacts is the most minor damage. However, it is precisely because of oxidized contacts that the speedometer needle can jump or fall to zero.

When the speed sensor wires are chafed or broken, the speedometer needle falls or jumps when you start the engine. The speed sensor in the 2110 is located in close proximity to the exhaust manifold. It is when the wires come into contact with the collector that the wires melt, wire breaks and short circuits occur. To determine the location of the break, you need to ring the wires using a tester and insulate them.

The next reason for a non-working speedometer is a failure of the idle speed sensor itself. The sensor operates based on the Hall effect. The speed sensor sends an electrical impulse to the vehicle's engine controller with a frequency proportional to the current speed of rotation of the vehicle's drive wheels. Through the wires of the electrical circuit, the generated current flows to the speedometer of the car and causes the electric motor inside it to rotate, deflecting the speedometer needle. On VAZ 2110-12 cars with an eight-valve engine, the speed sensor is located next to the dipstick for checking the oil level in the gearbox. To dismantle the sensor, you must remove the plug by pressing the latch. The sensor should unscrew easily. If the sensor is screwed tightly, unscrew it using a 22mm wrench. To make sure that the speedometer failure is correctly identified, use a new or known working speed sensor. The cause of the speed sensor failure may be the housing not being sealed and moisture and dirt getting inside. You can check the functionality of the new speed sensor while the car is moving or the front wheels are hanging up.

To check the speed sensor drive, you need to remove the sensor, grasp the sensor drive with your fingers or insert a 5-centimeter long stick into it and push the car back and forth a little. If you feel uneven rotation of the shaft when turning the wheels, the teeth of the speed sensor drive gear may be damaged or the gear is not installed. Remove the gear and inspect it. Replace the gear if the gear or gear drive teeth are chipped or deformed. After eliminating the malfunction, start the engine and while driving the car at a speed of 30..50 km/h, check the operation of the speedometer.

Speedometer malfunction

To check whether the dashboard is faulty, we recommend replacing it with a known working one from another car. Spare parts for VAZ 2110-2112 dashboards are no longer supplied, so car enthusiasts are left to buy new dashboards in stores or used dashboards at car dismantling yards in the city.

After purchasing the dashboard, you need to adjust the car's mileage on the speedometer. To adjust the mileage (winding up or cheating), call us, and our specialists will help bring the speedometer readings into line with the actual mileage of your car. We adjust mileage on domestic cars VAZ 2110, VAZ 2115, Kalina, Priora, Largus, GAZ-3110 Volga, UAZ Hunter, UAZ Patriot, UAZ Simbir in Kirov.

Call us at +7-922-900-70-60 and we will answer all your questions.

Technical characteristics of the VAZ 210-12 speed sensor: Operating temperature: from -40° C to +125° C Rated supply voltage, V: 12 Operating supply voltage range, V: – along the contact “1” circuit from 7 to 15 – along the circuit contact “2” with a load current of no more than 20 mA from 5 to 15 Maximum current consumption in the circuit of contact “1” with a supply voltage (13.5 ± 0.2) V no more, mA: 15

We are replacing the speed sensor

If the reason turns out to be the sensor, then you can replace it yourself. This can be done with a little experience with the operation of electrical appliances. Procedure:

Be sure to wear rubber gloves, since de-energizing the on-board system of the machine can cause unpleasant sensations.
Then you need to detect the sensor. As a rule, on a “tenth” generation car, the mechanism is located between the drive and the tip of the flexible shaft.
Having found the device, it is necessary to disconnect the block with the wire by removing all spring clips.
Next, use a 22 key to unscrew the mechanism from the drive.
At this point the work is almost finished, but only a little remains. Next, the new device is installed. This is done simply, but the main thing is to get the sensor rod into the center of the drive. Then you need to tighten all the components in the reverse order, secure them and begin checking the new mechanism.

Preparatory activities

Proper replacement of the speed sensor on a VAZ 2110 implies the mandatory purchase of a new device that meets all the requirements of your car.

Connector

Basically, when purchasing a device, follow two basic rules.

Choose a sensor whose connectors inside the block are marked -, A and +. Usually the designations 1, 2 and 3 are used there. There is no fundamental difference between them, it will simply be much easier to carry out the pinout with such markings. It is the incorrect connection that often becomes the reason that you have to seek help from a service station. And these are completely different financial costs.
The rod on the element must be made of metal. If the stem is plastic, it will last you about 6 months. It is not in your best interest to replace regularly. But don’t forget to check the metal rod for play, correct rotation, and the presence of a washer in the package.

Fuses and relays 2112

Fuse number Current strength, A Protected circuits

F1 5 License plate lamps. Instrument lighting lamps. Side light indicator lamp. Trunk light. Left side marker lamps
F2 7.5 Left headlight (low beam)
F3 10 Left headlight (high beam)
F4 10 Right fog lamp
F5 30 Electric door window motors
F6 15 Portable lamp
F7 20 Electric motor of the engine cooling system fan. Sound signal
F8 20 Rear window heating element. Relay (contacts) for turning on the heated rear window
F9 20 Recirculation valve. Windshield and headlight cleaners and washers. Relay (coil) for turning on the rear window heating
F10 20 Reserve
F11 5 Right side marker lamps
F12 7.5 Right headlight (low beam)
F13 10 Right headlight (high beam). High beam warning lamp
F14 10 Left fog lamp
F15 20 Electric seat heating. Trunk lock lock
F16 10 Relay-breaker for direction indicators and hazard warning lights (in emergency mode). Hazard warning lamp
F17 7.5 Interior lighting lamp. Individual backlight lamp. Ignition switch illumination lamp. Brake light bulbs. Clock (or trip computer)
F18 25 Glove box lighting lamp. Heater controller. Cigarette lighter
F19 10 Door locking. Relay for monitoring the health of brake light lamps and side lights. Direction indicators with warning lamps. Reversing lamps. Generator excitation winding. On-board control system display unit. Instrument cluster. Clock (or trip computer)
F20 7.5 Rear fog lamps VAZ-2112.

K1 – lamp health monitoring relay;
K2 – windshield wiper relay;
K3 – relay-interrupter for direction indicators and hazard warning lights;
K4 – headlight low beam relay; K5 – headlight high beam relay;
K6 – additional relay;
K7 – relay for turning on the heated rear window;
K8 – backup car relay.

Principle of operation

Domestic VAZ-2112 cars with a 16-valve power unit are equipped with an electromechanical speed calculation system. It consists of the following elements.

The speed sensor is the main element of the circuit. It is an electronic modernized pulse Hall sensor with a rod equipped with a gear.
Electrical wiring that provides connection between the electric control unit and the on-board computer, fuse box, and instrument panel.
Electrical fuse and contact relay. Provide protection against voltage surges in the network.
Electronic drive of the speedometer itself.

The operation of the entire system is ensured as follows:

An electromechanical speed sensor is installed on the vehicle's gearbox. It is driven by the drive gear of the gearbox. Rotation is transmitted through the EMF driven gear.
Rotation is converted into electrical impulses. For 1000 revolutions, 6004 pulses are generated.
Electrical impulses through the wires, or more precisely through the “2” wire of the electrical connector, enter the on-board computer.
The ECU calculates the received signals, transferring them further along the circuit to the speedometer receiver drive.
Electrical voltage with a certain current strength acts on the speedometer electric motor, causing it to turn at a certain angle.

This system is as reliable as possible. But, due to some factors, it also fails. The following will describe the symptoms that precede a speedometer malfunction.