What is the central locking of the car

Main elements and principle of work of central locking

Reliable door closing ensures the safety of the car and the safety of personal belongings, which the owner leaves in the cabin. And if in the past every door in the car had to be closed manually with a key, now this is no longer necessary. For the convenience of motorists there is a central locking system, which can be opened and closed at the touch of a button.

What is central locking

Central locking (Central locking) allows you to lock all the doors in the car at once. Of course, without the help of this mechanism, the driver could also unlock and lock his car: not remotely, but manually. Central locking does not affect technical features of the vehicle, that is why the producers refer this mechanism to the systems, providing car owner’s comfort.

Locking the doors with the central locking system can be done in two ways:

• centrally (when a single press on the key fob button closes all the doors at once);
• Decentralized (such a system allows you to control each door individually).

Decentralized system is the most modern version of the door locking device. In order for it to perform its functions, each door is additionally equipped with electronic control unit (ECU). In the centralized version, a single unit controls all the doors of the car.

Central locking features

Central locking in the car has several features that make the interaction between the system and the driver as simple and effective as possible.

• Central locking can successfully operate in conjunction with any alarm system.
• The trunk is also connected to the central locking system, but its opening can be controlled separately from the doors.
• For the convenience of the driver button remote control is placed on the key fob and in the car. However, you can close the central locking system mechanically by turning the key in the driver’s door lock. At the same time with the turn of the key will be blocked and all the other doors of the vehicle.

In winter, during severe frosts, the central locking elements may freeze. The risk of freezing increases if moisture enters the system. The best remedy for the problem is a chemical defroster, which can be purchased at an auto store. To get inside the car, all you have to do is defrost the driver’s door and start the engine. When the car warms up, the other locks will thaw by themselves.

Structure of the system

In addition to the control unit, the central locking system also includes input sensors and actuators (actuators).

Input sensors.

These include:

• door limit switches (limit switches) that transmit information about the position of the car doors to the control unit;
• Micro-switches that register the position of door locking components.

Micro-switches have different functions.

• Two of them are designed to lock the cam mechanism of the front doors: one is responsible for the lock signal and the other for the unlock signal.
• Also two micro-switches are responsible for fixing the position of the central locking mechanisms.
• Finally, another switch determines the position of the lever mechanism in the lock actuator. This makes it possible to estimate the position of the door relative to the body. As soon as the door is opened, the system closes the switch contacts, causing the central lock to fail to operate.

The signals sent by each sensor go to the control unit, which transmits commands to the actuators that close the doors, trunk lid and fuel tank hatch.

Control unit

The control unit is the brain of the whole central locking system. It reads the information received from the input sensors, analyzes it and transmits it to the actuators. ECU also interacts with the alarm system installed on the car, and can be controlled remotely using the remote control.

Actuator

The actuator is the final link in the chain responsible for direct door locking. The actuator is an electric DC motor, which is combined with the simplest reducer. The latter converts the rotation of the electric motor into a reciprocating movement of the lock cylinder.

In addition to the electric motor, pneumatic actuator was used in the actuators. For example, it was used by manufacturers such as Mercedes and Volkswagen. Recently, however, the pneumatic actuator has ceased to be used.

How the device works

The central locking of the car can be triggered both when the ignition is started and when the ignition is turned off.

As soon as the car owner locks the car doors by turning the key, a micro-switch in the lock is actuated to provide a lock. This sends a signal to the door control unit, and then on to the central unit. This element analyzes the information received and forwards it to the door, trunk and fuel filler flap actuators. The subsequent unlocking takes place according to the same scheme.

If the motorist closes the car using the remote control, the signal from it goes to the antenna associated with the central control unit, and from there – to the actuators, which provides the locking doors. At the same time, the alarm system is activated. In some models of vehicles, the windows on each of the doors may automatically be raised when the doors are locked.

If the vehicle is involved in an accident, all doors are automatically unlocked. A signal about this is transmitted from the passive safety system to the central locking control unit. The actuators then open the doors.

“Child lock in the car

Children can behave unpredictably. If the driver carries a child in the back seat, it is difficult to control the behavior of a young passenger. Inquisitive toddlers may accidentally pull the car door handle and open it. The consequences of a small prank are unpleasant. To rule out such a possibility, a “child lock” has been additionally installed on the rear doors of cars. This small but very important device eliminates the possibility of opening the door from the inside.

The additional lock, which blocks the opening of the rear doors from the interior, is installed on both sides of the body and is activated manually.

The way the mechanism is activated depends on the make and model of the car. In some cases, the lock is actuated with a lever, in some – by turning the slot. But in any case, the device is located next to the main door lock. Check your car’s owner’s manual for more information on using the “child lock”.

Dual locking system

Some vehicles have a double locking system, where the doors are locked from the outside as well as the inside. This reduces the risk of theft of the vehicle: even if the thief breaks the window, he will not be able to open the door from the inside.

The double lock is activated by pressing the central locking button on the key twice. To open the doors, you will also need to press the remote control twice.

The double lock has an important disadvantage: if the key or the locks were to malfunction, the driver would not be able to open his or her own car.

Central locking in the car is an important mechanism that allows you to close all the doors of the vehicle at once. Thanks to additional functions and devices (such as “child lock” or double locking system), the driver can protect himself and his passengers (including small children) against sudden opening of the doors during the trip.

What is a central locking system, what is it for and how to install it on a car?

Although central locks were originally created as an additional security element, nowadays they are more perceived as a device for providing additional comfort. And this is largely true, since the car owner has the ability to open all door locks at the touch of a button.

In addition to opening and closing doors, modern central locks (CP) are equipped with devices that control windows, fuel tank lid, luggage compartment.

This is an auxiliary element of almost every modern car, which can be installed on your vehicle. But before we should understand in more detail what it is, how it works and whether, in general, such equipment is needed on your car.

What is it

The full name for the central locking system sounds like the system of central locking of all available locks of the car. But this is too long and complicated designation, due to which motorists have switched to the abbreviated form and call the system simply central locking.

We need to understand what central locks in cars are and why they are needed. This auxiliary device is designed to perform simultaneous opening and closing of all car doors. Additionally, it can control the fuel tank hatch, window lifters, luggage compartment lid, etc. It directly depends on the specific type of device and its connection to the car.

The central locking system is positioned as an auxiliary system, which relates more to the elements of comfort than safety.

The locking is implemented by centralized or decentralized type of control. The centralized version uses a single control unit, which works for the benefit of all doors of the car.

But since the functionality of the central locking is constantly growing, its capabilities are expanding, and the number of controlled elements is increasing, decentralized control schemes have been implemented. The central unit is used here as well, but in addition each door has its own separate control unit.

The most common variant for modern cars is exactly the decentralized control scheme.

Device Features

Car central locking system consists of several control units, special sensors, actuators and other components, which are combined into one unified system.

Regarding the device, you should know some basic points:

• on modern cars, the system is controlled remotely, i.e. remotely, by using a suitable remote control. This is essentially a radio transmitter mounted directly in the car ignition key. From this remote control is a signal to the receiving antenna of the main control device of the lock. Typically, this signal can be transmitted at an average distance of up to 10 meters;
• There are input sensors in the central locking mechanism. These are micro-switches as well as limit switches for all existing car doors. So that this system can lock the doors in a certain position (close or open the locks), microswitches are used. A special limit switch is required to send a signal to the control unit and thus to fix its current or current position;
• On the front doors of automobiles, there are cam-operated mechanisms with microswitches. These are required to fix the current position of the lock. There is a special profile on the surface of these cams. One of the switches is responsible for generating the signal for locking and the other performs the unlocking function;
• The central locking mechanism’s current state is signaled by another pair of switches. When they are actuated, the signal is given that the door on the car is now locked or unlocked;
• The locking mechanism uses a lever mechanism. In order to fix its certain position and to determine the current position of the car doors, another special important switch is activated. When a car door is opened, the contacts on this micro-switch close;
• all switches send control signals to the general ECU as required. After these are processed, all these signals are now sent directly to the central unit. Therefore, there is a redirection to the blocks on the vehicle’s front doors, rear doors, gas tank hatch, etc. That is the control working blocks of the doors receive special signals, which include in the work of the corresponding actuators;
• Actuators act as actuators. They are connected to gearboxes and are essentially electric motors. When the gearbox turns the electric motor, the mechanism makes a reciprocating movement. This allows you to open or close a lock on a door or other parts of the car.

All of this applies to electric types of car central locks. It is worth noting that there are also pneumatic systems. But almost everyone has abandoned such actuators. It is very rare to find pneumatics in the central locks of modern vehicles. It is significantly inferior to its electric counterparts.

Operating principle

Now it is necessary to understand in more detail how the central locking system installed in the car works. Such a comfort system, provided for the car, does not depend on the current state of ignition. That is, the system will be triggered in any case, regardless of whether the driver has started the ignition or not.

The function can be roughly described as follows:

• When the driver’s door is closed with the key, the locking micro-switches are activated;
• a special signal is sent from the switch to the control unit of the vehicle door, after which the signal goes to the central unit responsible for all doors, hatches, luggage compartment;
• the control signal activates the actuators, i.e. actuators, and all locks are closed;
• so that the actuator is not mistakenly triggered again, a signal is created in the existing interlocking central unit from the microswitch signals. The same process is used to release the activated interlocking;
• so that the driver can lock or unlock the doors from a distance, the ignition key is equipped with a special button. In some cases, a separate key fob is provided;
• When the button is pressed, a signal is sent to the receiver (antenna) in the central control unit;
• the received signal is processed, and from the center is redirected to the peripheral units (doors, fuel tank, trunk);
• actuators, activated by a button on the auto key, block all available locks.

As an additional, but very useful element of comfort are used window closers. They are part of a single central locking system that allows you to close all the open windows in parallel with the closing of the doors. It is relevant for cars, which are equipped with electric window lifters.

As a result, the central locking system can perform three functions simultaneously:

• lock the doors;
• turn on the security system (alarm);
• automatically raise all the windows if one or more are lowered.

Such multi-functional central locks are convenient to use, but at the same time their cost increases. Whether the car owner wants to pay extra for a window closer is a purely individual question.

It is important to note another advantage. When an accident happens, the central locking system allows you to automatically unlock all the doors. This is done by passing a signal from the unit responsible for controlling the car’s passive safety systems to the central control unit. The central unit already sends commands to the actuators, which open the doors.

Installation

Given all the possibilities and objective benefits, many motorists are thinking about installing a central lock with their own hands on their own vehicle.

Those cars are lucky to have the possibility to install central locking system, even if you do not have it in your car. But the car has all the slots and other nuances necessary for quick and easy installation. For installation you will need to buy a central locking kit, and on the available slots do the job.

But if you have an older car, where even at the factory the central locks were not installed, you will have to do everything from scratch. This is not a reason to give up the idea, but the task is not the easiest. It is recommended to consult with specialists and study the scheme of your car beforehand.

The entire procedure can be divided into 3 main stages:

• the choice of a central locking system;
• Preparation of materials and tools;
• installation.

The motorist should choose a suitable kit in advance, prepare everything you need for the job, and based on the step by step guide, implement your idea.

Recommendations for the choice of equipment

The choice should begin with the manufacturer. If you want to get a reliable and high-quality central locking system, you can’t cut corners on your purchase. You must categorically refuse any cheap Chinese variant. Such economy will not benefit you and your car.

The options are the next point of choice. Choose only the features that you will really use. Any additional option affects the cost, and overpaying for them is not always reasonable.

Experienced motorists, who actively use central locking systems, recommend choosing equipment equipped with a window closer. Although it is an additional option, it is considered the most useful. It is suitable for cars, which are equipped with electric windows. This option is useful because the driver and his passengers often forget to close the windows due to negligence or haste. Closer will do it when the central locking is activated.

Another useful addition will be the function of automatic closing after a certain time interval. This option is not on all models of central locking, but for many it is very helpful.

It is important to note that the automatic closing does not always play a positive role. There are situations when the motorist leaves the keys inside. If the automaton is triggered, there will be a problem in the form of inability to get to the keys.

The assortment of locking systems is quite extensive. Choose proven manufacturers, as well as carefully examine the list of available options. Soberly assess what you need, and what is better to refuse. Do not rush to buy the most advanced and multi-functional central locks, even when the budget allows it.

Materials and Tools

Before you connect and set up your new central locking system, you will need to prepare the necessary tools and materials. A wiring diagram is already included with the central locking system. Based on it, it will be much easier for you to do all the work yourself.

In general, motorists need to have:

• central locking kit;
• wiring;
• insulating tape;
• wire cutters;
• door guns;
• drill;
• screwdriver;
• screwdriver; .

Much depends on the design features of the particular vehicle. On some cars, the central lock is mounted with the use of a minimum set of tools with a set of equipment. Others have to disassemble a number of elements of the car, which may require some additional tools.

Step-by-step guide

Now you can proceed directly to the connection of the central locking. The main components of success can be called the presence of desire, a little patience and free time to perform the task at hand.

Before you connect the central locking to your car, make sure that the acquired lock is fully equipped. Sometimes manufacturers or rather sellers cheat by offering certain components for a separate fee.

If everything is ready, lay out the kit in front of you in a comfortable place, prepare the tools and materials required for work. Following the step-by-step instructions, you will be able to figure out how to install the central locking yourself.

1. Open the doors of the car, proceed to the removal of the interior trim. Be careful, since many of the fasteners are plastic, and it is very easy to break them. If necessary, they can be replaced, but it is much easier to initially do everything delicately, without creating additional problems.
2. Next, install the wiring in the doors. The central lock is necessarily equipped with a pull rod with a boom, which is connected directly to the pull rod on the door itself. The drive is carefully connected to the door. For this purpose, choose a convenient protruding metal part.
3. The wiring is pulled to the control unit, which will be responsible for the operation of the central lock. Here, too, caution is important. Hide all wires so that they can be accessed, but the risk of mechanical damage was minimal. Use clamps and insulating tape in the process to combine multiple wires into one bundle in different areas along the entire length of the wiring. If it is possible to place the wires under the dashboard, do so.
4. On the doors, you can return the trim material. This is where the door pistons will be needed. They are often made of plastic, but metal products are also found. Depending on what type of gun is provided on your car.
5. After you have put the door panels back in their places, you can move on to connecting the wiring to the control unit. This stage is rightly considered the most difficult and demanding in terms of quality of work performed. Connection involves connecting the minus wire, which is made in the form of a black wire, with the mass, and the plus wire goes to 12V. This wire is usually colored red. But first, check with the scheme from the manual to the central lock.
6. After completing the connection, the central locking must be connected to the already installed security system. This will open and close the doors automatically, as well as activate and deactivate the alarm system by pressing the appropriate button on the remote. In the hood is a block with fuses. To him lead wires from the central locking system.

You can not say that the central locking installation procedure is incredibly complicated. There are nuances and strict requirements in terms of sequence and accuracy of the work. If you have a certain experience and knowledge about the device own car, the car owner will be able to do everything on their own hands.

If you doubt your abilities, but you are sure that you need a central locking system, you should only turn to professionals of the relevant profile. Professionals can cope with the connection for literally a couple of hours. For beginners, due to the increased accuracy and excessive caution, the work takes 3-6 hours.

Each car owner decides for himself to do everything himself or to invite professionals. The only fact is that the presence of central locking simplifies the door control and allows you to close the car with one button, without having to check each door, window, fuel tank hatch or trunk door separately.

Helpful Tips

There are some common mistakes that motorists regularly make when trying to install a central locking kit on their vehicle themselves.

And here we are not talking about those who do not read the manufacturer’s manual, but try to do everything, relying on their experience, some knowledge or trivial method of trial and error. It’s obvious that you need to study the manual from the manufacturer of the central lock before installing it, understand the scheme and only then begin work.

To avoid the mistakes of other motorists, it is highly recommended:

1. Use corrugated tubes, where the wires from the central lock are placed. The central lock consists of a fairly large number of wires, each of which can get damaged, frayed, kinked. As a result there will be partial or complete failure of the whole system. To prevent this from happening, special tubes with a corrugated structure are provided. By placing wires in them, they are much better protected from damage. If you additionally use a layer of duct tape, the likelihood of wire breakage will be practically zero.
2. If it is necessary to bend the rods. For some reason, motorists believe that it is very fragile, and therefore leave it in its original form. But the shape of the pull rod sometimes prevents it from being properly placed under the door trim. Try to bend it a little to give the necessary shape. This will make installation more accurate and convenient.

To install the central locking system or not, is up to everyone. But those motorists, whose cars are equipped with such systems, claim that the central locking is very useful, convenient and practical element of their vehicle.

Nowadays central locks are regarded only as an element of comfort. But it is quite fair to call it a part of the car safety. After all, exactly central locking allows you to remember to close all the doors, performs the function of window closer, prevents unauthorized attempts to drain fuel from the gas tank or get into the car through the luggage compartment.

Considering all these factors, it’s not surprising that almost all leading car manufacturers equip their models of any price segment with central locks even in basic version. But if you have already bought a car without central locking, it doesn’t prevent you from installing the system by yourself or with the help of specialists. The main thing is to buy a quality kit with the necessary features you need.