Any standard security system installed at the factory by the manufacturer and an alarm installed in the car at the request of the owner by a dealer or third-party electrician should make it as difficult as possible to steal the car. It is unrealistic to completely eliminate this, but criminals will not be able to start the engine just like that; security systems block this possibility when triggered. Unfortunately, they can do this in any other situation when no one is going to steal the car.
Blocking by security complex
Starting problems arise as a result of the fact that security systems are implemented in the power plant control circuits. This is done to prevent the car from being stolen if an attacker was still able to get into the cabin. In practice, this is implemented by installing intermediate relays (controlled by an alarm) in the open circuit of the starter, fuel pump or ignition power supply circuits. If one of these components is not supplied with voltage, starting the engine will not be possible.
Electronic components included in modern security systems begin to malfunction over time, making it difficult to access the car or preventing the owner from starting the power unit. Experts list the following as the main reasons for refusal:
- Damage to the onboard electrical wiring supplying the security system.
- Failure of the immobilizer blocker installed in alarm systems with the ability to remotely start the engine.
- Failure of the electric relay blocking activation of the starter, fuel pump, ignition system.
- Unauthorized entry into a vehicle or attempt to steal it.
- Violation of two-way communication via the CAN bus.
- The appearance of errors in the firmware.
If the alarm system blocks the engine from starting, when the ignition is activated, the characteristic sound of the starter or the engine “grabbing” is not heard.
Separately, the list of possible failures includes a low charge of the key fob batteries. In this case, it is possible to disarm the car, but the engine will not be able to start. This happens due to a violation of the code signal transmission - the door locks will open, but other functions will not be active. Attention!
Interruptions in the operation of any car alarm can begin within 5 years after installation. The increase in service life depends on the quality of the system installation.
Disabling locks using the service button in the cabin
The alarms have a service function for disabling engine blocking - Valet. Its task is to transfer the system to maintenance mode. Instructions for turning it on:
- Place the key in the lock.
- Activate the ignition for a couple of minutes. Disable it.
- Hold the special service button for 15-20 seconds.
- The system will emit a short beep and the LED indicator will light up.
Service mode disables all protective mechanisms. After troubleshooting and fixing the problem, you need to re-enable the deactivated functions.
You can also turn off the alarm and remove the lock in emergency mode - there is a special button in the cabin. It must be held for 15-20 seconds, after which the signal indicator will light up and go out. When the light stops glowing, you can try to start the engine.
Ways to disarm a car
Before you begin to remove the engine lock, it is necessary to determine what exactly caused the failure. Electronics can notify the driver of failures with service messages or incorrect operation:
- The indicator light (LED) is flashing at an unusual rate. Its uncharacteristic mode of emitting light pulses indicates possible problems with the firmware.
- The presence of a pictogram on the LCD display of the key fob about arming the car. In this case, a notification is sent via two-way communication that some functions are not available.
- Continuous sound siren and hazard warning lights. The inability to disarm the car indicates that the protection is activated and the engine will not start.
- Abnormal operation of the key fob. If, when you press a certain button, another, unprogrammed action occurs, this indicates a malfunction of the electronic components of the head unit or remote control.
- Lack of response to pressing key fob buttons. If this happens on all existing remote controls, then the head unit has mechanical damage.
To restore the functionality of the car alarm, the driver should try to reset it to factory settings. The process is individual for each type of security system; the sequence of actions is indicated in the accompanying documentation. Along with the installation kit there is a brochure, which it is advisable to keep in the car. If the booklet is lost, the user manual can be downloaded from the Internet or a search request can be made.
If the alarm goes off, you can remove the block using the secret VALET button. This is a standard operating algorithm for all types of security systems. The button is needed to enter the service mode, reset settings or completely disable protective functions. To prevent attackers from using it, it is hidden in the internal cavities of the dashboard, and access to it is possible after dismantling decorative panels, plugs or other controls. As a rule, the button is located in the area of the driver’s left knee, but individual installation cannot be excluded when the master places it in a place previously agreed upon with the owner.
Attention! When buying a used car, you should definitely find out about the location of the VALET button, as well as the contact details of the workshop where the installation was performed.
If the alarm does not allow you to start the car, you can use the standard method of removing it from standby mode. Turn the ignition on and off, then press the VALET button 3 times. But this will not help in all cases. To unlock, other algorithms of actions or entering a PIN code are used. You should prepare for such a situation in advance: find out the sequence of actions, inform all users of the machine about the methods of “resuscitation”.
It is also worth writing down the contact phone number of the technician who installed the security system. Usually they use individual installation algorithms and know how to remove the block. If the car does not start, you need to contact the mechanic, describe the situation, and perhaps he will be able to remotely correct the driver’s actions. In case of failure, the machine will need to be delivered to a service workshop.
There is another option when it will be impossible to “revive” the power unit, which the owner may not be aware of. The car will not start with the key or will stall while in motion if it is equipped with a satellite alarm. Such systems are installed on premium cars, and when buying a used car, the new owner may not know about its existence. Blocking occurs for a trivial reason: there are not enough funds in the current account.
How does this device work?
The immobilizer is quite simple. In addition to the special chip (immobilizer chip transponders), which we have already mentioned, there is also a board built into the car that reads information from this chip. The signals, the “secret code,” are sent by the transponder chip in the form of electromagnetic pulses. The built-in control board, using a special electromagnetic coil, reads signals from the key and compares them with those recorded as a sample in the car’s computer memory.
If everything is in order, then the third component of the immobilizer - the electromagnetic relay - will remove the lock from the electronic on-board control systems and the car will start. If the control board does not find the necessary signals, then all vital systems of the car will be blocked.
The principle of operation of the immobilizer is to prevent an attacker from starting the car’s engines and driving away. It is impossible to visually determine whether a car is equipped with an immobilizer or not. There are no external signs, and there is no sound during its operation either.
Today, cars can be equipped with different types of immobilizers: contact, contactless, and “protecting in motion.” In contact immobilizers, the chip is located in the car key, and the reading board is in the ignition switch. Of course, car keys can be stolen, so as an additional anti-theft measure, a small keyboard for entering a secret code is possible next to the ignition switch. Or an additional sensor for scanning the fingerprint of the rightful owner of the car. In contactless immobilizers, the chip that sends signals can be built into a key fob, a card shaped like a bank card, or something else. (It turns out to be a kind of pocket immobilizer). And the board that receives the signals is more of an antenna that can be installed in the trim of the car interior. The range of such an antenna is small - no more than ten centimeters.
But in immobilizers, which are called “protecting while moving”, the range of action of the receiving board is large. But here the reaction principle is different - engine blocking is possible only when the car is moving. This system is very effective in a robbery attack. Suppose they threw out the driver, took his place, drove off, and then suddenly the engine stalled
It is only important that the transponder key fob that triggers the car locking mechanism remains with the legal driver
While studying this topic, another question may arise: “what is a standard immobilizer in a car?” It's simple. Standard means included in the factory configuration of the car. Often its system is very deeply integrated into the design of the car. But if manufacturers have not provided anti-theft devices, then an additional immobilizer can be installed.
Troubleshooting
If software methods fail to start the engine, then the fault lies in mechanical damage to the components of the security system. The work can be done on site, but it is better to have the car towed to a garage. First of all, it is necessary to determine the alarm operating algorithm. When installed normally, it can block the motor through several channels:
- CAN bus with complex programming of modes.
- There is an open circuit in the starter push coil power supply circuit.
- Fuel pump blocked.
- Turn off the ignition and injectors.
There are other types of blocks that are placed individually or handicraft. Often such algorithms are forgotten, and it becomes extremely difficult to bypass them. First of all, take out the control unit and related elements. They are located behind the fuse and relay panel to the left of the steering column. The location is extremely inconvenient due to limited access and confined space.
Attention! It is better to remove the head unit and peripheral components from the niche in which they are located. The length of the connecting wires is sufficient to move all elements of the security system to a distance sufficient for comfortable operation.
First, check the fuses that protect the electrical circuits of the car alarm. They are located on wires in special sockets at a short distance from the head unit. A blown fuse should be visible: a thin current-carrying wire behind the plastic partition will be destroyed. If it appears intact, check the integrity of the component with a multimeter. When you don’t have the necessary equipment at hand, you can replace all fuses with known good ones. Then check the operation of the alarm.
The problem may lie in poor-quality connection of the security system wires with the standard electrical wiring of the car. In order for the alarm system to prevent car theft, the power supply circuits of the devices responsible for starting or operating the engine are interrupted by blocking relays. If the connection is not made well, the conductors may oxidize and lose contact. When troubleshooting, you need to remove the old insulation on all twists and reconnect.
In the case when the blocking is carried out via the CAN bus, you can try to disconnect all the connectors suitable for the control unit and relay. Motor protection is provided by normally closed contacts. After disconnecting the connectors, try to start the engine. If this does not help, you need to find all the relays connected to the control unit. They are located in close proximity to it, can be attached to its body or simply hang on the wires.
To bypass the blocking, you must manually close the relay contacts. On the body of the latter there is a diagram of the operation and switching options. You can also use a multimeter to look for open contacts. The contacts are closed by bridging them with a thin wire. You need to be extremely careful not to short-circuit the portals of the relay power line, which will lead to a short circuit and blown fuse. As a last resort, you can carefully open the plastic case. Below it there will be an anchor that must be pressed to restore the integrity of the chain.
What is this, an immobilizer?
How is this device different from a conventional security system? First of all, the degree of protection of the car increases significantly with its use. This device has a complex intelligent system that allows you to control the mechanism only from close range, and not remotely, as is the case with a conventional alarm. This means that when the door is opened, attackers are not able to intercept the signal coming from the device’s key fob. To intercept it, you need to be directly in the car.
Please note that owners of cars with alarms that are serviced in dubious workshops may be at risk. The fact is that making a copy from the alarm key fob is quite simple and does not take much time. And it’s easy to steal a car with an existing copy of the key fob. But as for the immobilizer, it is difficult to make a copy of it, because attackers usually do not have a master card.
Modern security immobilizers are famous for their compactness. They are installed in hidden places. And if you install the immobilizer correctly, it is almost impossible to determine its type and location. But that's not all. Some types of devices have an anti-robbery function that does not even require the participation of the owner.
Nuances of alarm operation
The latest generation security systems are complex electronic components that include a number of functions that make it difficult to access or steal a car. But incorrect operation can create a problem for the driver himself, when the locks on the doors refuse to open or the engine cannot be started. A periodic inspection of your car alarm will help you avoid an emergency situation.
Attention! To receive prompt assistance, you need to have the installer's contact information with you. They can be stored in the car and the notebook of the smartphone.
Car alarms will last longer and without failures if they are installed in specialized workshops. In addition, you must follow a few simple rules:
- Do not check the serviceability of fuses or relays while away from home or a parking lot. Accidental damage to components can cause the power plant to lock up.
- Change the battery in the key fob promptly. If the remote control operating distance decreases, this is a sign that the battery is depleted.
- In case of minor malfunctions in the operation of the security system, it must be immediately turned off, diagnosed, repaired, or replaced with a new one.
- Do not allow moisture to enter the control unit and relay. Oxidation of contacts can completely damage the system.
Whatever anti-theft system is installed on the car, electrical equipment is responsible for blocking the engine or starter. This allows you to narrow down the troubleshooting area for starting the engine. Success depends on the type of alarm installed and the number and complexity of interlocks. In some cases, you may need the help of an auto electrician so that your actions do not cause more damage to electronic components.
Why do you need an immobilizer?
In modern cars, the standard immobilizer responds to a transponder with a unique code in the key. This approach has the following features:
- if a thief cuts out a similar key, then due to the lack of a chip, starting the engine is impossible;
- the technology prevents theft, but prevents the owner from using autostart.
Therefore, there are many electronic anti-theft devices on the market that allow you to bypass the car system. The device consists of a main unit and a digital device for blocking the motor. The package also includes tags that are kept by the driver. When starting the engine, the immobilizer checks them - without this, the car will not start. Non-standard models are chosen for reliability, refusal of light or sound signals, regular updates and improvements. And an experienced thief can easily deal with a factory immobilizer, because possible options for hacking standard algorithms have long been known.
What is more: benefit or hassle?
An electronic immobilizer is a device that has a number of undeniable advantages. Firstly, it will not allow the attacker to start the engine and drive away. Secondly, even if a car thief figures out how to bypass this protection, it will still take him time, during which he can be caught. In addition, if there was no careful preparation for the theft, then you may not immediately understand where the device is located.
Well, for the car owner, having an immobilizer does not cause much trouble. Unless we are talking about a contactless type of device with a long range. The transponder key fob in this case runs on batteries, which need to be changed on time
And also if this is a transponder key, then it is important not to hang it in one bunch with all the other keys. Good luck on the roads!
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