Understanding Car Security Systems (Explained For Beginners)

An alarm system is made of up the keys, the locking system, and many other components that all work together to protect your car and help prevent hijackings and theft.

A wide variety of modern technologies are now being used to track stolen cars, including RFID, GPS, and RTLS.

It is not just about loud sounds when it comes to car security systems. There are certain features that you may want to look for in your security system.

Your vehicle’s security sensors and/or alarm will notify you when your system is triggered.

Audi A6 car key lock/unlock for security system
Audi A6 car key, lock/unlock for security system.

By using starter kill, you can start your vehicle remotely without compromising its security. In an armed vehicle, attempting to turn on the engine will disable the starter.

These sensors make it possible for you to know if your car is at risk for a security issue, even if you aren’t in the car or nearby it. If your car is touched, moved, bumped, or tampered with, the sensors will react and the security system will notify you.

There are many different things that make up a car’s security system and it’s a good idea to understand these components and how they work.


Cars with transponder keys are more secure. The original car keys and duplicate car keys are authenticated by a very small computer chip inside them. A coded message will be sent to the key when the ECU is plugged into the ignition.

A real key will respond back to the Engine Control Unit if it receives the coded message. The car will only start once the messages have been authenticated. An automotive locksmith may sometimes have a difficult time replacing car keys with transponder keys.

When the transponder key was introduced during World War II, it was initially used to identify friendly aircraft on radar. In order for the pilots to know which planes were friendly, the military forces used them to identify friendly planes.

Nowadays, transponders are used in other types of transportation as well. All the major car manufacturers also use transponder keys.

The embedded chip in transponder keys is powered by the radio signals sent by the car, not by a battery. In order to start the car, the key must be pressed into the ignition or hovered very near the dashboard for the radio signals to activate the chip.

A transponder key is not required if you simply lock and unlock the doors of your car, but if you want to start your vehicle, you will need it. You can either contact your local automotive locksmith or your car dealer if you need a new car key.

Immobilizer System

In addition to serving as a deterrent to vehicle theft, car immobilizer systems (also known as engine immobilizers) are excellent security tools. The purpose is to prevent hot-wiring and theft of cars by people without keys.

Statistically, there have been fewer car thefts in recent years since immobilizers were installed in cars. You’ve probably already used this technology without even realizing it if you’ve purchased a car in the past 20 years.

In recent years, car dealerships have stopped using traditional car keys in favor of key fobs or smart keys. Therefore, the key’s base has buttons that can be used to lock and unlock doors, open trunks, and, in some cases, start cars remotely.

Nowadays, most key fobs don’t even have a key attached to them. A key fob with an Engine start button allows you to start the automobile simply by being inside the vehicle. The car keys of today may be considered an extra layer of security.

Various types of key fobs and smart keys contain transponder chips. These chips communicate a passcode to the car’s immobilizer technology when you start the engine or insert the key fob.

Vehicles will start if the pin code in the key fob matches the immobilizer code. Otherwise, you won’t be able to start your vehicle.

The wrong code will usually trigger an alarm on most immobilizers. A security service is also alerted if a theft attempt is attempted by some digital auto systems. A security company will contact the user to confirm the theft has occurred and that there is no one inside the car.

Immobilizers from some companies now offer a fixed code and a changeable code as part of a two-tiered security system. You alter the second code every time you start your car by reading it from the transponder.

After checking the permanent code, the immobilizer needs the second changing code, which it compares to the one saved in the database, and then starts the automobile. In the absence of the second code, the car won’t start.


The purpose of a car alarm is to prevent theft by installing a device inside the vehicle. Most car alarm systems feature similar components, although there are different types.

You will be able to arm and disarm the alarm with the controller that comes with the alarm system. Different parts of the vehicle are also equipped with sensors.

Sensors on or in the vehicle detect vibrations. The vehicle can also be monitored for movement. The sensors will activate a siren if they detect movement or vibration, which creates a loud sound that is supposed to scare away thieves and increase awareness of the area.

The purpose of it is to deter theft. With some modern car alarm systems, you can receive notifications through your phone if something goes wrong with your vehicle through advanced notification systems.

You should never rely solely on these for car security, even though they can be more beneficial. There is, however, a problem even though car alarm systems are very popular, and they are installed in the vast majority of vehicles.

People have become desensitized to hearing alarms due to their prevalence and the number of false alarms. As a result, they end up ignoring them because they’ve heard them so often.

When a truck or a motorcycle drives by, a car alarm can be triggered because it detects vibrations. As a result, people start ignoring false alarms altogether, and eventually, they no longer pay attention to them at all.

The sound of quality alarms was used to deter thieves in the past. It has become increasingly possible for car burglars to disable car alarms due to technological advancements.

They are able to shut off their car alarms extremely quickly, so they don’t attract any attention when they do so. Upon walking outside in the morning, you find that the vehicle has been stolen.

Theft-alarm System

Trigger mechanisms are used in devices or systems to trigger alarms. There are usually a few switches and a dropped relay in the trigger.

Drop relays cannot rest until manually set unless they are activated. Even if the trigger switch is disabled, the alarm system will continue to work without the manual reset.

To prevent the accidental triggering of the alarm, you can add a timer to the trigger circuit.

An alarm can also be triggered using push buttons installed on the hood, doors, and trunk. It is usually the trunk and hood latches that are coupled with the closed switches where the doors close.

It is very important to combine pushbutton switches with motion-sensitive switches to ensure the vehicle is protected. Additionally, mercury can be used as triggers for trunk and hood lights.

The Switches to Control Triggers

Remote anti-theft alarms are turned on and off by a trigger control switch. In order to prevent the thief from disarming the system, the switches should be arranged so the owner can easily start the vehicle without triggering the alarm.

There are many types of control switches that can be found on the exterior of vehicles, but the toggle switch is the most common.

The disadvantage of this switch is that it must be waterproofed in both its wiring and the switch. Someone may deactivate the switch if they find it.

There are many types of switches that can be fitted outside a vehicle, including the locking type. In addition to providing outstanding security and protection, such switches are visually pleasing and use “Pickproof” type locks.


There is no doubt that alarms are crucial components of remote anti-theft alarm systems, which are used to turn on the horn or may also be equipped with separate alarms. Alarms can be simple or they can be complicated.

Some only sound when the door handles are messed with and others are very sensitive and will sound if someone or something gets too close to the car or accidentally bumps into it.

Door Locks

Below the latch is the actuator for the power door lock. The actuator is connected to the latch, and the latch is connected to the knob at the top of the door by a rod.

A latch is connected to a door opening mechanism when the actuator moves the latch up. Outside door handles are not accessible when latches are down because they are disconnected from the door mechanism.

There is nothing complicated about this system. Gear reduction is provided by a small electric motor that rotates spur gears. The actuator rod is connected to a rack-and-pinion gear set by the last gear. Using the rack, the motor’s rotation becomes linear motion so the lock can be moved.

Interestingly, when you move the latch, the motor won’t turn, even though the gears and latch can be turned by the motor. The motor engages a centrifugal clutch attached to the gear that accomplishes this task.

With the motor spinning, the clutch unlocks the smaller metal gear, enabling the motor to drive the door latch. Only the plastic gear with the clutch will turn if you move the door latch yourself.

Passive Anti-Theft System

When the ignition key is removed, a door is shut, or the vehicle is turned off, passive devices arm themselves automatically.  

It is not necessary to take any additional steps. Once the driver closes all the doors and turns off the car, the systems turn on automatically.

You may not be able to start your vehicle without your key. Most push-to-start cars with specialized keys work in this manner. When you use passive anti-theft systems, you don’t have to worry about forgetting to turn them on.

Key Fob

Key fobs are small, plastic devices that are used for unlocking and starting vehicles without traditional keys. Many new cars have them, and they’re quite popular. In order to unlock and start the car, key fobs transmit a small radio signal.

A receiver unit in the car receives the signal from the key fob. Activating the car’s engine is then accomplished by sending a signal to the receiver unit.

Most of the time, the key fob is found in or near the driver’s door. Locking and unlocking the car is possible, as well as starting the engine. Key fobs can also be programmed to release the parking brake or open the trunk.

In 1955, Robert Adler patented the first keyless entry system. In order to operate the door locks on a car, multiple radio frequencies and a code were used. Depending on how many security features it offers, modern key fobs can have as many as eight or more buttons.

A door lock button is one of the most common security features. Color coding helps you remember what each button does.

Consumers are increasingly using keyless entry devices. Most budgets can afford them, and they offer convenience and security. In the future, these devices will likely become even more advanced as technology advances.

Remote Start

An engine starter that uses a remote or in some cases an app on your smartphone or smartwatch allows you to start your car at a distance.

Factory-installed systems can be expensive, whereas aftermarket kits can cost over $100. A basic kit can cost under $60 while a more advanced one can cost over $200.

How remote engine starters work, how they benefit, and if you can mount them yourself are discussed here.

The remote start tool is very easy to use once it has been installed correctly. The remote start system inside a vehicle is extremely complex. Your engine can be turned on and off with the push of a button thanks to many pieces of hardware.

It is necessary to install the correct wiring, a bypass module, a control module, and a remote transmitter for your car remote starter to work.

Remote starters work by mimicking the engine starting sequence that your key triggers when you unlock the door. The remote car starter, however, does not require an ignition key to function.

In this case, your starter mechanisms and ignition switch must be wired up to the control module. The remote transmitter on your car can send signals to the remote-start system when it is installed.

Remote-start control modules receive commands from your remote transmitter via unique radio frequencies once installed. Control modules receive these signals for remote starting, unlocking, and locking, among other functions.

A remote start module, additional wiring, and a key fob are all added to your vehicle with aftermarket remote starters.

Power door locks can also be controlled by wiring them in and setting them up.  One-way remotes transmit commands to your car without receiving confirmation from them.

The installation of a two-way remote starter is similar to that of a one-way remote starter. There is only one major difference between the two, and that is the remote control.

Depending on the remote, the car provides feedback after receiving a command via an LED or screen. It is also possible to display the countdown until the engine shuts off on some systems that have LCD screens on the remote control. 

An app can be used in conjunction with the remote control to control some remote start systems. Remote starts with app-based controls that need a network connection to operate.

They are cellular-based. With cellular connectivity, however, the vehicle and operator can be controlled wherever both have a cellular connection, rather than just within a quarter mile or so.

A remote starter is a good investment for your vehicle for many reasons. The engine oil is warmed and circulated. The oil becomes less viscous and flows better when the car is starting from a cold engine.

As a result, the operating temperature is reached more quickly. You can keep comfortable inside the house while it warms or cools to a manageable temperature within a few minutes when it is started remotely in extreme weather.

That means you don’t have to worry about wiping down your windows as much. Having the engine started remotely can clear foggy or frosty windshields before you get behind the wheel.

Other accessories can also be triggered by it. The heated steering wheel or seats can often be turned on when you remote start your car. 

In a parking lot, it can be helpful in finding your car. You just have to push a button on the remote and it will flash the lights or sound an alarm so you can locate it.

Final Thoughts

If you have a car, it’s common sense to keep it safe and protect it from theft. A car security system can help you protect your car and anything you keep inside it safe. Knowing the different options and components of a security system can help you choose the best option for your car.


10 Car Safety Features – CarsDirect

Guide to Car Safety Features (consumerreports.org)

Your Car’s Key Fob May Have Hidden Features – Consumer Reports

7 Critical Features of a Car Security System – GPS Tracking | Rollr