
I created a list with a couple of other technicians one day. The list was full of the most common and the weirdest things we’ve seen trigger a car alarm. Here’s what we came of with:
Breaking a window or forcibly opening a door
Most Car alarm systems come with shock sensors that are triggered when they detect an impact or sudden jolt, such as a door being forced open or if you have a (Glass Brake Sensor) you can protect your car against vandalism. This triggers the alarm system, alerting the owner or nearby individuals of a potential break-in.
Attempting to open the hood or trunk without a key or remote
Many cars are equipped with sensors that detect when the hood or trunk is opened without a key or remote (Tilt Switch sensor). This is to prevent the theft of valuable items or to prevent tampering with the car’s engine or electrical components.
Someone getting too close to the car or leaning on it
Some car alarm systems come with proximity sensors that detect when someone gets too close to the car or touches it. This can trigger the alarm and alert the owner or nearby individuals of a potential threat or vandalism.

A sudden impact, such as a car accident or a heavy object falling on the car
As mentioned earlier, many car alarm systems come with shock sensors that detect sudden impacts or jolts. This is to alert the owner or nearby individuals of a potential accident or damage to the car.
A change in the car’s angle, such as if it’s being towed or lifted by a tow truck
Some car alarm systems come with tilt sensors that detect changes in the car’s angle. This is to prevent theft or unauthorized towing of the car.
Someone trying to start the car without a key or remote
Many car alarm systems come with ignition sensors that detect when someone tries to start the car without a key or remote. This is to prevent theft of the car.
A sudden change in temperature or barometric pressure
Some car alarm systems come with temperature and pressure sensors that detect sudden changes in these factors. This is to prevent damage to the car’s engine or electrical components.
An electrical short circuit or power surge in the car’s system
Some car alarm systems come with electrical sensors that detect short circuits or power surges in the car’s electrical system. This is to prevent damage to the car’s electrical components.
A low battery or a malfunctioning battery in the car or remote
Many car alarm systems require a functioning battery in order to operate properly. A low or malfunctioning battery can trigger false alarms or prevent the alarm from sounding when necessary.
A malfunction in the car’s security system
Like any electronic system, car alarm systems can malfunction due to faulty sensors or control modules. This can lead to false alarms or prevent the alarm from sounding when necessary.
Loud noises nearby, such as fireworks or construction work
Some car alarm systems come with noise sensors that detect loud or sudden noises. This is to prevent false alarms or alert the owner or nearby individuals of potential threats.
Strong winds or vibrations
Some car alarm systems come with vibration sensors that detect strong winds or vibrations. This is to prevent false alarms or alert the owner or nearby individuals of potential threats.

Animals or insects crawling or flying near the car
Some car alarm systems come with motion sensors that detect movement near the car. This is to prevent false alarms or alert the owner or nearby individuals of potential threats.
Malicious interference from nearby wireless devices
Some car alarm systems can be interfered with by nearby wireless devices such as walkie-talkies or other car alarms, causing false alarms or preventing the alarm from sounding when necessary.
A malfunction in the car’s ignition switch
Like any electronic system, car alarm systems can malfunction due to faulty ignition switches leaving the alarm system unaware of whether or not the vehicle ignition is on or off.

Intense sunlight or a reflection that may trigger a motion sensor
Some alarm systems use motion sensors that can be triggered by sudden changes in light, such as when the sun shines directly on the car or reflects off a nearby surface. This can cause false alarms, but you can usually adjust the sensitivity of the sensor or use a sunshade to reduce the risk of triggering the alarm.
A nearby electromagnetic field
Certain alarm systems may be sensitive to electromagnetic interference, which can cause false alarms or malfunctions. This can be difficult to diagnose and fix, but you may need to consult a professional installer or electrician to resolve the issue.
A sudden change in air pressure
Some alarm systems are designed to detect sudden changes in air pressure, such as those caused by explosions or sonic booms. This can be useful in detecting potential threats, but it can also result in false alarms if the system is too sensitive or if there are other sources of air pressure changes nearby.
Chemical vapors or fumes
Some alarm systems may use sensors or detectors that are sensitive to certain chemicals or fumes, such as those from cleaning products, paint, or gasoline. If you notice that your alarm system is triggered by these substances, you may need to adjust the sensitivity of the sensors or avoid using these products near your car.
Radioactive materials or radiation that may trigger a certain alarm
Some high-security alarm systems may be designed to detect radioactive materials or radiation, which can be used in certain types of threats or attacks. While this is a rare trigger, it’s important to be aware of it if you have a high-security alarm system and to take appropriate measures to protect yourself and your car.