What to do when your car alarm keeps going off

By Kennedy Ilediagu
Publish on July 17, 2019

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There are commonly 4 causes of this issue and here's what to do when your car alarm keeps going off! Check the solutions and explanation from Naijauto experts below!

Have you been in a situation where your car alarm just keeps going off? Your car isn't being broken into, but the alarm doesn't stop. It's a sign that something has gone wrong in the alarm installations.

The kind of alarm installed in your car also has a role to play in this issue. The alarms found in the latest generation of cars heavily differ from what is obtainable in older models. It's also easier to locate what the problem actually is, in a newer car model than the ancient ones. For instance, if you buy a premium OBD2 scanner, it can read the trouble codes in the control unit of your car alarm and let you know what's going on. If you purchase the cheap ones from a low budget vendor, it will be a lot difficult to read these codes.

Whichever it is, here are the reasons and a step by step guide on deactivating the alarm, brought to you by Naijauto.com!

1. A defective key fob

Many of the cars currently being manufactured come with a key fob. This makes keyless entry a feature that is here to stay. The key fob enables you to open and lock the doors of your car, unlock the trunk and start the engine in some cases.

With all of this linked to one key, the alarm system will be linked to it as well so that when someone without the key tries to enter the vehicle, the alarm would go off. However, if the key fob goes bad, it can send the wrong codes of instruction to the car and this will trigger the alarm of the vehicle. Once you notice this, you might have to get a new key fob from a car accessory dealer and have it reprogrammed with your car electronic system.

You can also check if the batteries have gone bad and change them. Faulty or dead batteries can also cause the key fob to malfunction and signal the car alarm.


A faulty key fob sends wrong codes to the alarm system, causing it to go off

>>> Read more about the key fob here: How to change Mercedes-Benz key battery (either chrome key or smart key)?

2. Dead or low car battery

When the battery of your car starts to get low and you start the engine, the alarm will blare. This is because the car alarm system feels something has gone missing. If you try turning on the car again and it happens, you'll have to inspect the battery. With the help of a multimeter, you can check the amount of voltage coming from the car battery. Anything from 12.5 volts and below, you might have to replace the battery or get it fully charged.

Asides low or dead battery, the alarm can go off if the terminals are worn out. This is because inconsistent power will be sent to different parts of your car. The alarm system will misinterpret it as the battery is low and it will go off. In this case, all you need to do is to clean off the rust on the terminals. With the help of an iron brush or sponge and fizzy carbonated water or drink, you can clean off the rust in no time. (Here's How to clean corroded car battery with Coca Cola, read now!).


WIth the battery terminals corroded, the alarm might misinterpret

3. Faulty latch and oversensitive shock sensors

Let's start with the shock sensor. This is the sensor that makes your alarm blare when someone touches the car with a particular force or in a manner.

When the shock sensors get too sensitive, the slightest touch will trigger the alarm immediately. This means even if fruit from a tree, a bird or hailstones land on the vehicle, the alarms will go off. If you don't get it fixed, the alarms might drain your car battery and you'll have multiple issues in your hands. Though the shock sensor can be fixed easily. You can check your car manual to find out more but most times, all you need do is to twist it and it will work just fine.

Another sensor to keep an eye on is the latch sensor for the hood. This is a sensor that sends a message to the alarm to go off when the bonnet of your vehicle is being forced open. If the latch sensor starts getting bad, a slight shake of the bonnet will trigger the alarm. If some even touch the bonnet mistakenly or dirt gather in the bonnet, the alarm will go off instantly.

>>> Check further details on car sensors here: 7 car sensor types used in modern automobile engines

All you need to do is clean the bonnet and the sensor itself. The latch sensor can be found around the headlamps of your car. If you have a cleaner for your brake pads, you can apply it to a towel and use it in cleaning the latch sensor. Ensure you have removed the battery connectors before you start cleaning and also be careful with the sensors so you don't damage it.

Video: Repairing a stuck latch on a car door

4. The alarm was installed wrongly

In Nigeria where there are a lot of car accessory and security vendors, expect to meet the good and bad. If you purchase your alarm from someone who is not knowledgeable, it won't be installed right. This can constantly trigger the alarm. You can use a multimeter again to find out if enough power is being passed through the wires. When certain, go for diagnostic tests and get it fixed immediately.

With all that in mind, you now know what to do when your car alarm keeps going off, see more car tips and advice by car experts on Naijauto.com.

Kennedy Ilediagu is an experienced wordsmith and a creative automotive writer for Naijauto.com. His forte ranges from vehicle maintenance and latest industry updates, to car review articles. He is also a brand management and content creation expert who has worked with Daily Posts (United Kingdom), ESUT Egg Day magazine, and many others for years. Digital copies written by him inform, educate and engage readers globally. When Kennedy is not writing, he is busy taking care of animals, traveling or watching football.




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