Effective protection of the car from theft can be provided by the presence of several devices having different purposes, while they are united by one concept - a security complex. One of the important elements in this case are immobilizers. What is it will become clear from the following description.
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The automobile security complex includes mechanical protective equipment, an alarm system, a standard immobilizer, and means to alert the owner of the car. Most often, it is the alarm that takes over the protective functions. However, not the last role in all this is assigned to the immobilizer. If you want to provide the most reliable protection against theft, you need to install several security devices that are independent of each other.
So, let's look at immobilizers. What kind of devices these will become clear if you determine their principle of operation. The ability to activate and deactivate such a device should be only one person, that is, the owner of the car. For these purposes, an immobilizer key is used. There are models that support manual code entry, but their prevalence is not so great. The electronic code key is made in the form of a chip, during the manufacture of which a special cipher was inserted into it, which is long enough so that the attacker could not pick it up in a short period of time. The chip is in a convenient housing. Starting the engine of the machine will be possible only when the owner inserts the device into a special socket to deactivate the immobilizer. If the system works with manual key entry, then its shutdown is possible only after entering the character sequence specified by the owner.
Principle of operation
Answering the question: “Immobilizers - what is it?”, It is worth noting that the principle of their work has not changed in recent years. Here we are talking about the presence of a gap in the electrical circuits that are vital for the operation of the engine, and the key that he has is able to eliminate this gap. However, lately electronics has stepped forward significantly, which made possible the introduction of certain adjustments to the operation of the device.
So, we continue to deal with such a concept as immobilizers. What is it, it will become more clear if we consider their device. Today they have an electronic unit through which the adjustment and control of the functions of the device are carried out. Using the microprocessor, the key is authenticated, after which the necessary circuits are closed. In addition, companies engaged in the production of immobilizers additionally offer a number of devices that increase the reliability of their work. These can be closing relays and fuel solenoid valves.
What is it created for?
The immobilizer is designed to prevent theft, even if the car is already opened. A closing relay is installed in the place where the electric circuit of the motor is broken, so the microprocessor checks the authenticity of the key, and then does not connect the circuit independently, but only sends a signal to the required electromagnetic switches. Only after that they are included in the closed mode. The immobilizer becomes even more reliable only through the use of such relays.
If we talk about the fuel valve, it simply closes the fuel line. It is closed in a free state, so gasoline does not enter the vehicle’s power system from the tank. But after the microprocessor accepts the correct password, the microchip sends a signal to the valve. When it is received, the fuel line opens. Some immobilizers (which we have already determined) can be connected to various sensors, which makes them an analogue of an alarm. For certain models, it is possible to control through the paging system.
Using a standard immobilizer unit and various additional devices described above, it is possible to form a whole security complex for a car.
Types of fixtures
There are models on the market that differ in design features that affect not only the functionality, but also determine the reliability of the entire system.
Devices requiring contact
Contact immobilizers assume control by means of a key inserted into the well or brought to the mating part of the lock. However, such systems are almost never used. They are characterized by a rather important drawback - the cracker knows in advance where they are located.
Contact immobilizer involves entering a special code through a key switch. The number of key combinations is such that it is impossible to select a cipher, sorting through various sequences. The number of combinations in such systems is 10 to the power corresponding to the number of keys for entering the code.
No contact required
Contactless immobilizers work due to the fact that the system receiving antenna is installed on the skin of the cabin, and the control process is carried out by means of a card or key fob. This type is the most common. The fact that it is not clear where the immobilizer is located allows for more reliable protection compared to the others. However, there are more advanced solutions.
Non-contact immobilizers with a small radius are characterized by the fact that the receiving antenna operates at a distance of no more than 10 centimeters. Boarding a car is accompanied by bringing a tag to a hidden device, which allows you to disarm the system by unlocking all the circuits. If the offender sees exactly how the driver turns off the immobilizer, where he brings the key, then it will become clear to him that a certain protection is used in the car. It is this shortcoming of systems with a small radius of action that is fundamental. If the attacker sees where to put the tag, then he understands where the receiving antenna is located. That is why the car must be disarmed as discreetly as possible.
Immobilizers that “protect on the move” allow you to start the engine and start off, but then they block all systems and the car stalls. Such systems are very relevant in the event of a robbery, when the driver is thrown out of the car, keys and documents are taken. However, proper storage of the transponder allows it to remain with the owner. When a certain distance separates the car thief from the owner of the car, the engine stalls.
How to stop an already stolen car?
Immobilizers are also useful for this. What does it mean? The fact is that in their design there is a special type of lock. Locked circuits are not broken if the engine is not started. They will only open during its operation. Immobilizers are equipped with built-in relays for breaking circuits (usually 3 pieces).
Not so long ago, micro-devices began to be used in the form of special switches controlled by the central unit by means of high-frequency signals and automobile wiring. It is difficult to find and neutralize them, since wires from the central unit do not go to them. Such a relay does not seem at all different from a conventional automotive relay. Sometimes it is built into the safety block instead of the standard one, and it is almost impossible to distinguish them. Some systems can be equipped with a dozen of these immobilizers, that is, it will take quite a while to search for them.
Such devices should still be used as additions to the alarm, and not its replacement. The meaning of their installation is hidden and invisible to other people, and only an immobilizer is capable of this. "Kalina" and other models of domestic cars have long been protected from penetration into the cabin by just such devices.
How to disconnect?
Sometimes it happens that the owner of the car needs to turn off the immobilizer - in case of malfunction or obstacles to the operation of the installed alarm, or for other reasons. This is best done in a specialized workshop, as self-intervention often becomes a source of additional problems - the car will stop turning on.
Usage Recommendations
- it is worth having not one immobilizer key, but at least two: one should be with you, and the second at home, in case of an unforeseen situation;
- The electronic device should not be hung in a common keychain;
- if you lose the key, you need to recode the system as quickly as possible;
- install an immobilizer (VAZ with you or another car - it doesn’t matter) is required only by authorized dealers;
- to recognize the transponder at the greatest possible distance, it is necessary to orient it in relation to the antenna plane in parallel.
By using non-standard installation schemes, reliable vehicle protection can be guaranteed.