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.
None The diagram shows that the output is connected to the ECU terminal. Terminal number:
- – block January 5.1, also BOSCH M1.5.4N (engine 21120, 1.5 l);
- – 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 simple.
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. 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 wrench. To replace the sensor drive, use a “10” wrench 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).
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.
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.
None A little test:
- 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.
Sometimes they do this: they make a tap from terminal 9, and, without engaging the gear, move (push) the car. The engine remains switched off. Pulses will appear on the tap, detectable even with a voltmeter. The voltmeter itself must be a pointer type.
The presence of pulses indicates a malfunction of the speedometer, and the absence of pulses indicates a malfunction of the sensor. However, the speed sensor may not receive power or ground (see above).
It will not be possible to fix a faulty speedometer - it will be easier to replace it. But first you need to find out exactly what the problem was.
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).
Video with instructions for replacing the sensor
A car's speedometer is an important component of a safe and comfortable trip. Every car owner knows what this device is intended for, but not everyone can immediately figure out the reason why the speedometer stopped working. And this is an unpleasant thing when the speed indicator shows incorrect numbers or has stopped functioning altogether.
There is a high probability of speeding and getting a fine from a traffic police officer. Or not fit into the turn at all. To avoid these unpleasant situations, you should know the principle of operation of the device and the most likely causes leading to its failure.
Speed sensor malfunctions
Signs of a sensor malfunction may include:
- unstable operation and incorrect speedometer and odometer readings;
- cessation of stable engine operation at idle;
- errors generated by the computer (P0500 – no sensor signal, P0503 – intermittent sensor signal).
The problems listed above may result from:
- poor contact in the sensor connector due to contamination;
- violation of the integrity of the wiring from the sensor to the ECU;
- mechanical failure of the DS drive (in older VAZ 2110 models).
Do I need to change
Not only the speedometer and odometer readings, but also the quality of the fuel mixture supplied to the cylinders, the idle speed of the vehicle, engine stability and fuel consumption depend on the information received by the ECU from the sensor.
A failed DS will “confuse” the electronic unit, which simply will not understand whether the car is moving or standing still. As a result, the speed will begin to fluctuate, the engine will stall at idle, and fuel consumption will increase.
Checking a mechanically driven speed sensor is not difficult. On the removed sensor, we find the pin and turn it with pliers, having attached the connector to it in advance. If the speed sensor is working, the arrow on the instrument cluster will jump, if there is no reaction, then there is a problem with the drive or electrical wiring.
Checking the wiring to the instrument cluster is also not difficult, take a paperclip (you can use any other metal object) and insert it into the middle pin on the connector, then touch it to the engine housing, the arrow on the combination should twitch, otherwise you need to look for the cause in a wiring fault or sensor connector (oxidation, breakage, etc.).
Reasons why the VAZ 2110, 2111, 2112 speedometer stopped working
The operation of any speedometer is based on the Hall effect. The controller receives data from the speed sensor, which produces a signal proportional to the tire rotation speed. On cars of the “tenth” VAZ family, one of the most common reasons for speedometer failure is contact oxidation. Cleaning them will take about 10-15 minutes; this is the simplest and most effective solution to the problem.
This video describes the reasons why the speedometer on a car does not work: But, if this does not help and the speed meter still refuses to work in a VAZ 2110, VAZ 2111, VAZ 2112, then the owners of these cars will have to prepare for more painstaking work. The following possible malfunctions include:
- Deformation of wires in domestic cars is also a common problem. It is necessary to visually check all wires for defects. If nothing was found, to be completely sure, “ring” the wire; the internal conductors may be damaged;
- The fuse should be checked. It may simply simply burn out;
- The problem may be hidden in the speed sensor itself. In VAZ 2110, 2111, 2112 cars, in this case, it is necessary to urgently replace the faulty mechanism. But, first, it’s still worth checking the mechanism for functionality: remove the device from the box and connect a drill to the device. If it is working properly, then torque will be transmitted to the device;
- It is advisable to check the instrument panel for faults. If the instrument panel was removed, then incorrect reinstallation could result in the arrow touching the trim.
These are the most likely reasons that answer the question: why does the speedometer not work? This principle should be observed for both owners of an “injector” engine and owners of a “carburetor”. If, after going through all the procedures, the problem was not detected and solved, then in this case it is necessary to carry out a comprehensive diagnosis of the vehicle.
Causes of malfunction on a VAZ 2110 with a carburetor
In the “ten” with a carburetor, torque is transmitted from the gear in the gearbox (gearbox) through a flexible shaft to the speedometer mechanism. In most cases, it is the shaft that may be causing the problem.
Flexible drive in the shell is the main cause of speedometer malfunction
If the speedometer stops working, first check the mounting points of the flexible drive . Tighten the nuts. If even after tightening the speedometer does not work, then the shaft has probably broken or there has been a breakdown in the mechanism on the instrument panel. In this case, the flexible shaft must be replaced. You can do this type of repair yourself. When installing a new drive, avoid extreme bending. Incorrect installation of the shaft will lead to unpleasant knocking.
If everything is in order with the flexible shaft and the instrument panel mechanism, then the problem is in the gear. It is located inside the checkpoint. We recommend that such repairs be carried out at a service station.
