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How Long Do Car Alarms Go Off For?

how long do car alarms go off for

It’ll come as no surprise to anyone that car alarms are crucial for safeguarding your vehicle and deterring theft. Nowadays, the majority of car alarms produce loud alerts that notify owners of potential dangers and intimidate intruders. When someone attempts to break into or vandalize your car, a really loud alarm let’s everyone know what’s going on.

Although it may seem like audible car alarms continue indefinitely, they actually have an automatic shut-off feature. After sounding for a certain duration, the car alarm will stop on its own. So, how long do car alarms typically sound? Let's find out the answer together.

How Long Do Car Alarms Go Off For?

As an important safety component, loud alarms are there to tell the owners that the threat is happening. However, when going off for too long, car alarms can cause prolonged noise disturbance to the surrounding area.

According to statistics, a typical car alarm can go off for anywhere from 30 seconds to a few minutes before switching off automatically. However, the time may be different depending on the type of alarm system your car has and where you live. Faulty or broken car alarm systems can last for up to 20 minutes which will definitely cause a disturbance to anyone who lives around the area.

How Do Car Alarms Work?

Car alarm systems are designed to protect vehicles from theft and unauthorized access. Traditional car alarm systems consist of various sensors, a computer, a receiver that responds to your key fob, and a loudspeaker. They work together by using sensors to detect specific events and trigger an alarm in response. If the sensors detect irregular movements, the alarm system will be triggered. For example, if someone tries to open the door or break a window, the sensor will activate the alarm.

Once triggered, the control module activates the alarm, which can include a combination of audible alerts, such as sirens or horn honking, and visual alerts, like flashing lights. Some advanced car alarm systems will send a notification to a smartphone app, allowing owners to receive alerts and control the system remotely. The loud alarms aim to attract attention and deter theft or vandalism while alerting the owner to the potential security breach.

What Triggers Car Alarms?

As sensors in car alarms can detect movements and then set off the loudspeakers, there are many factors that can trigger car alarms.

Theft or illegal break-in

Traditional car alarm systems use shock sensors to detect vibrations or impact on the car while also having motion sensors to detect movement inside or around the vehicle. If someone tries to open the door without a key fob or break the window, these sensors will definitely activate the alarm.

Unintended touches

Car alarm systems are sensitive to certain types of disturbances, including vibrations and sudden impact. Even a slight touch or vibration, such as someone brushing against the car or a passing object making contact, can potentially activate the alarm system.

This sensitivity helps ensure that any unauthorized attempts to access or tamper with the vehicle are detected and the alarm is triggered. So it’s a good idea to be cautious and avoid unnecessary contact with the vehicle to minimize the chances of triggering the car alarm unintentionally.


In most cases, sensors in the car alarm system are typically calibrated to ignore smaller movements or sounds, including those caused by pets. However, extremely large or forceful movements, such as a large dog jumping on the vehicle or a pet inadvertently activating a door handle, could potentially trigger the alarm system.

Wrong use of keys

Car alarm systems can only respond to signals from a specific key fob which is paired with the vehicle. Each key fob has a unique identifier or code that is recognized by the car's alarm system. If an incorrect or unrecognized key fob is used, the alarm system will be triggered, so using the right key fob is vital.

Activated sensors

Sensors are vital components of a car alarm system. By keep tabs on the area surrounding your car, sensors help to protect your vehicle against theft and vandalism. The truth is whenever the sensors are activated, the alarm will be triggered.

Car Alarms Keep Going Off: Common Causes Explained

You may have experienced that jarring moment when a car alarm disrupts the peace, triggering a cascade of loud sounds that echo through the streets. While these alarms are intended to protect vehicles from theft or vandalism, there are instances where they seem to be excessively sensitive, leading to frequent false alarms. Here are the possible reasons why your car alarm system might keep going off again and again.

Dead battery

Car alarm systems rely on electrical power to operate, including the sensors, computers, and sound-producing components. For car alarm systems, a dead battery means that the alarm system has lost its charge and is no longer functional.

When the battery is dead, the alarm system may either fail to activate the sensors when a threat is detected, or it might act erratically by going off for no reason. To determine whether the battery of a car alarm system is dead or not, you can activate the alarm system with your key to lock the car. If the alarm system does not respond or produces weak or no sound, it may indicate a dead battery.

If your battery is dead, you can replace it with a new one or recharge it, but remember to ensure your car's security while you are recharging the battery by doing it in your garage or keeping an eye on your car.

Malfunctioning key fob

Utilizing wireless signals, the key fob is a small remote control device that allows the owner to arm or disarm the alarm system, as well as locking and unlocking the doors. A malfunctioning key fob can significantly impact the performance of a car alarm system and cause various issues.

A faulty key fob can cause intermittent signals, triggering the alarm system constantly or failing to activate it all together. In this case, a longlasting sound will go off. To avoid this situation, you should pay attention to your key fob’s performance. If you can't use your key fob to lock or unlock the door, chances are the key is malfunctioning. To solve this, you need to send it for repair or just buy a new one.

Faulty latch sensor

The latch sensor is designed to detect the opening or closing of specific vehicle entry points, such as doors, the trunk, or the hood.

It monitors the status of these entry points and sends signals to the alarm system when a breach is detected, triggering the alarm to go off and alerting the owner. However, just like the malfunctioning key fob, a faulty latch sensor can disable the sensor completely or continually set the siren off. If your latch sensor fails, you need to get a professional to fix it.

How Long Do Different Types of Cars Alarms to Go Off For?

As mentioned above, the amount of time that car alarm systems to go off for may depend on the type of system you use. Here are some common types of car alarm systems.

Aftermarket alarm systems

An aftermarket car alarm system refers to a security system that is installed in a vehicle after it’s left the factory. Purchased separately and installed by a third party, such as an automotive electronics specialist or an aftermarket retailer, aftermarket alarm systems can be considered additional security system for your car.

Normally lasting between 5-10 minutes, these aftermarket systems can be highly sensitive and can get triggered if they detect that the car is just slightly tilted.

OEM alarm systems

OEM (Original Equipment Manufacturer) alarm systems, also known as factory-installed alarm systems, are security systems that are installed in cars during the manufacturing process by the original vehicle manufacturer. These alarm systems are specifically designed and integrated by the manufacturer, providing standard levels of security.

When OEM systems get triggered, they can go off for about 5 minutes and you can disarm the car using your key fob. Compared to aftermarket systems, OEM alarms do go off for a shorter period of time. In the vehicle industry, experts prefer OEM alarm systems, as they offer a convenient and factory-fitted security solution for vehicle owners, providing peace of mind and protection against theft and unauthorized access.

Bonus Tips: How to Shut Off Malfunctioning Car Alarms

If you are in a situation where your car alarm keeps going off and the sound causes disturbances, use the following tips:

Use both keys and lock to unlock driver's side door

First, rapidly lock and unlock the driver's side door using your keys. This action can reset the switch and stop the alarm from sounding, as some vehicles are wired to trigger the alarm when specific doors are opened. If the driver's side door doesn't work, attempt the same process with the passenger door. 
You can also start the engine, which might deactivate the alarm. Some cars are programmed to recognize the ignition as a non-theft signal, making the alarm stop. Turning on the engine often resets the alarm system back to its original state.

Check the panic button

A panic button on a car key fob is a dedicated button, specifically designed to trigger the car's alarm system in emergency situations. It’s usually located on the key fob alongside the buttons used for locking, unlocking, and trunk release functions.

If you can’t open the door on the driver’s side easily, attempt to press the panic button on your key fob. Panic buttons are easily recognizable, often featuring a red or orange color and commonly labeled with a horn symbol.

Remove the fuse

To deactivate your car alarm, you can also locate and remove the fuse responsible for powering it. Fuses distribute electricity to various components in your vehicle, so removing the alarm's fuse will not affect the power supply from the main battery to your engine. Car alarms have an individual fuse since they need to operate even when the engine is off.

The specific location of the fuse can vary depending on your car model, but it’s typically found in the engine compartment. Consult your owner's manual for a diagram and the location of the alarm's fuse box. Using a pair of pliers, carefully extract the relevant fuse to disable the alarm.

Disconnect the battery

Provided that your battery can be disconnected without special tools, the first step is to open your car's hood, locate the battery (a rectangular or square-shaped box), identify the terminals with (-) and (+) symbols, and then disconnect the wires using a wrench or a socket. By following these steps, you can totally cut off the power supply of your car, including the alarm system.

Note: Disconnection is only recommended under the most extreme circumstances. You should only do so if you can ensure your car’s security or if you have tried this before.

Check the owner manual again

It’s never a bad idea to read the owner's manual again. Almost all manuals mention car alarm systems. If your car alarm systems can’t function properly or keeps on going off, just go back to your manual and check the details again.


How long does a car alarm go off in the UK?

Most car alarm systems will go off for anywhere between 30 seconds to a few minutes. In most cities, authorities will take action if the alarm goes off constantly for more than 20 minutes, which is considered a noise nuisance.

Does a car alarm stop on its own?

It depends. Car alarms typically do not stop on their own once it has been activated. Car alarms are designed to continue sounding until they are manually deactivated or until the alarm system detects that the threat has been resolved.

However, some car alarm systems may have a built-in timer or duration limit. In such cases, the alarm may automatically stop after a specific period of time, typically ranging from a few minutes to up to half an hour.

How can I silence my car alarm?

You can silence your car alarm using your key fob or your key. By pressing the "unlock" button on your key fob you can deactivate the alarm. If your car uses the traditional key, you can insert your key into the ignition and turn it to the "on" or "start" position to silence the alarm.


Common car alarm systems go off for around 30 seconds to a few minutes. As a vital component of car systems, alarms can enhance the security of vehicles and provide peace of mind to owners. However dead batteries, malfunctioning key fobs, and faulty latch sensors can cause your car alarms to go off irregularly.

As technology continues to evolve, we can expect car alarm systems to become even more advanced and intelligent. Have you ever recorded how long your car alarm goes off for? How do you usually deal with irregular alarms? Share this article with your friends if you find it useful and leave a comment below, we'd love to hear from you.


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Editor from Reolink. Interested in new technology trends and willing to share tips about home security. Her goal is to make security cameras and smart home systems easy to understand for everyone.