Toyota Corolla Car Alarm Keeps Going Off – How To Fix?

Any of us will feel more annoyed when our car alarm keeps ringing for no reason.

Unfortunately, this is one of the problems many Toyota Corolla drivers face. This condition will be aggravated when it chirps at night, in an area with small children, or a densely populated place.

To handle this situation, you only need to disconnect the car battery, your car alarm will stop ringing, but this is not a permanent way to disconnect the signal.

Below is a list of common causes that will help you diagnose why your Toyota Corolla car alarm keeps going off.

Toyota Corolla Car Alarm Keeps Going Off – What Is The Cause?

There are many common causes of this condition. Before you bring it to the repair center, you can refer to some of the common causes below to fix the problem quickly.

1. Low Battery

If your battery is running low, your car alarm might be one of the first things to alert you. Car alarm systems are designed to warn when the battery is running low.

When you try to start your car with low battery power, a car alarm may sound to warn of a problem with your battery.

However, if your alarm just randomly goes off even when you’re not in the car, it could indicate that the battery is running low or the connections have corroded and are sending inconsistent electrical signals.

A voltmeter applied to the battery can tell you the type of charge in the battery. Anything lower than 12.6 volts is an indication that your battery is dying and needs to be replaced.

In addition, car batteries can also corrode and rust if after a long time of use without maintenance.

If your battery is still charging well but the terminals are corroded or not clean, then you can buy a chemical battery cleaner to help clean them and make the connection better.

To clean the battery, make sure you disconnect the battery before performing cleaning operations for your safety.

2. Faulty Key Fob

2020 toyota corolla key fob
2020 Toyota Corolla Hatchback Keyless Entry Remote

Your key fob is an electronic remote access device for Toyota Corolla modern cars. It helps you to close or open the car remotely and gives you the ability to set an alarm on the car.

Because it’s powered by a small battery and it’s usually just in your pocket, it’s likely to run out of battery frequently. 

That can cause the key to send a signal to the car and the alarm to go off continuously.

Your simplest fix is to check the battery status and replace it with a new one. Here is a common cause and is also easy to detect and replace. Be sure to check this cause before looking for other reasons.

3. Hood Latch Sensor Issues

The makers of the Toyota Corolla have designed your car’s alarm system to rely on a smart roof latch sensor that will trigger an alert if someone is trying to force it to open the hood.

This is made possible by the hood latch sensor that detects the hood movement. It can warn about people who intentionally open the roof or have bad intentions with your car.

If the door latch sensor is dirty, due to adhesive or oil, it will send an inconsistent signal and trigger a car alert.

In addition, the hood’s latch sensor may be clean but not installed properly. If a certain type of wire is damaged or poorly connected, the machine’s latch sensor will send the wrong signal to your car’s alarm causing it to work.

Due to the design of the car, the hood will accumulate a lot of dirt and debris that can affect the door latch sensor. If you look under the hood and find it covered in dirt, cleaning the sensor may solve your problem.

4. Shock Sensor

One of the ways car alerts work is by using a vibration or shock sensor. For example, it can detect when someone is trying to open your door. Sometimes the sensors can be too sensitive and the result is a normal collision that also causes it to buzz continuously.

In this case, you may need to recalibrate it to be a little less sensitive. So it can avoid the beep continuously when there is a slight bump like a cat jumping on a car or someone accidentally touching it.

If you test the shock sensor yourself and find that simple vibrations such as a slight bump in the vehicle cause the alarm to sound, you can adjust the shock sensor yourself.

The collision sensor is usually located on a small control box that can be found below the driver’s side panel. You can look around to find a small box with a dial and adjust it down to be less sensitive.

How To Deactivate The Car Alarm?

In some cases, you may not know exactly why the car alarm is ringing continuously, and you want to turn it off quickly to avoid disturbing the people around.

To turn off the alarm, you can do a few temporary ways below:

1. Open Or Close The Car Door

You only need to open the car door or close it when the alarm is still going on. Some alarm systems can detect when the correct car key has been used and turn it off. So you only insert the key lock, unlock it and see if that’s the cause.

You can also try this if you have a key fob by pressing the lock and unlock button near the car.

2. Start The Car

The warning function is effective in alerting the car owner in case someone intentionally steals or damages the vehicle.

So if you can start the car, the sensor system will know that you are in and it will stop the alarm.

3. Disconnect The Fuse

In case you can’t figure out why and try many ways but can’t get off the alarm, you can simply disconnect the fuse that controls the alarm on your car.

Its location can be in the engine compartment or the entrance from the cabin itself. So you can locate the fuse for the alarm and remove it. If you have a replacement fuse, try putting a new one in and see if that solves the problem.

4. Disconnect The Battery

When all else fails, you can simply disconnect the battery in your car. This will leave your car without electricity and unable to control functions.


In any case, where your car alarm keeps ringing, you should also consider the possible causes listed above.

However, this is only a temporary way to mute potentially annoying sounds.

You should still bring it to the car repair company for more in-depth inspection and handling. You should avoid the car battery running intermittently or intermittently to solve this problem, as it can damage the system.

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