The Anti theft Light Blinks When the Car is Off Explained

Anti Theft Light Blinks

Who would have ever believed that a removable steering wheel is known to be the first anti-theft technology in cars! Fast forward to the present, car manufacturers now install warning lights in cars to ensure a better and safer driving experience.

Among these warning lights is the anti-theft system or immobilizer system. This security light is installed in your car for protection against theft.

The theft light will start to blink if you try to open the door or hood without the car key. The blinking of the theft light is an indication that the car security system is functioning properly. It can also mean that there’s a problem with it. Some faulty systems of the car can activate the security system.

So this article clearly explained some of the reasons why the theft light blinks when the car is off.

The Security Light on My Car's Dashboard

On your car’s dashboard is the security light which serves as the indicator for the car’s anti-theft system, and it serves two main purposes:

When the Engine is ON

When the security light stays on when the engine is running, this indicates a fault in the anti-theft system.

When the Engine is OFF

In some cars, the security light blinks when the ignition is off, indicating that the security system is active and working correctly.

Why Does the Theft Light Blink When the Car is Off?

The theft light blinking when your car is off is an indication that the security alarm is active. So, if there is an attempt to break into your car, the alarm will ring.

To accompany this trigger is a code that will also be sent to the engine management system. This locks up the engine so it doesn’t start. The theft light can blink continuously when the car is off if there’s a fault detected with the car.

The engine may also fail to start in other instances.  When this happens, it’s advisable to have your car checked by a certified auto mechanic.

Here are some of the reasons why the theft light blinks when the car is off:

The Security Alarm Is Active

Naturally, the theft light should blink even when the car is turned off because this is the way the security system has been designed. Once the car is locked, the immobilizer system and the alarm become active instantly.

This causes the red light to stay on for several hours when someone tries to open your car without the car keys.

The anti-theft system is designed in such a way that the theft light and the alarm are automatically triggered when someone tries to open the door (locked) without the car key or tries to open the hood of your car.

To alter this as the owner, you will need to shut it off once you are near the car. But to activate this security system, you will need to press the lock on your car keys.

To turn off the anti-theft light, insert the key into the car door and try to unlock but do not release it. Make sure you hold the car keys for about 20 to 30 seconds.

In cases where there’s issues with a part of the car, you will be unable to turn off the theft light or shut off the alarm. In that case, you need to have your car checked by an expert – for the purpose of resetting the car’s anti-theft system.

To disable the anti-theft system, press the unlock button on your remote key to unlock the driver’s seat and then turn the ignition switch to the “ON” position.

Problems With The Anti-Theft System

If the anti-theft system is faulty, it can cause the theft light to blink when the car is on.

Most times, the engine will not start, or the alarm may go off and may not go off even after opening the door with the car key.

A faulty anti-theft system could result from:

  • Poor wiring triggers the theft light to blink continuously. If the installer of the security is not trained properly, this could cause the security system to misbehave.
  • The use of electronics of poor quality for the anti-theft module. This is usually the case with faulty anti-theft systems.
  • A problem with the carlock door can also cause the theft light to blink when the car is off. For example, if the lock actuator is not responding well, it may cause the anti-theft alarm to go off willy-nilly.
  • The theft light can also be activated even if the doors are closed and the engine is not running. A car’s door lock actuator can be affected by a bad connector or water leaks, especially during wet monsoon. When this happens, fixing the leaky part can solve the problem. Also, the connector can be sealed with protective grease. 
  • An issue with the car key can also turn on the theft light. Car key issues can result from damaged keys, batteries, or broken immobilizer chips. Continuous use or physical damage may cause the immobilizer to fail over time. So when this chip is damaged, the system may fail to recognize the car key’s security code/signal.

Bad Alternator

An alternator is a very important component of a car and it powers the car battery and other electrical accessories such as headlamps.

When the alternator is faulty, it may fail to produce enough power to charge the battery or other accessories, thereby causing them to either underperform or overperform.

This can also trigger the theft light which causes the light to stay on until the alternator is repaired or replaced.

If you notice that your car headlamps are dim or extremely bright, it could be a sign of a faulty alternator. Other signs to look out for include a bad smell, grinding noise, and difficulty in starting the car. 

The alternator is easily damaged by fluid leakages – a leak from the power steering fluid is expected to cause the alternator to malfunction.

Besides, a bad driving habit can overwork the alternator and cause it to wear and tear unnecessarily. So you need to properly maintain your car to prevent the alternator from going bad.

Regularly clean the alternator and change any failing parts once they are discovered. 

Usually, a car’s age and long use are directly proportional to the wear and tear. So do not wait for the symptoms of the bad alternator to appear, ensure you clean and service your alternator regularly to prevent it from failing prematurely.

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Usually, the flashing of the theft light when the car is off should not be a concern. This is exactly how the car’s security system has been designed to work. So it’s quite normal. 

But in other cases, especially when you cannot start the engine, it could indicate some issues with your car. The anti-theft light can be triggered if your car has faulty parts or accessories. 

Never hesitate to have your car checked if you notice the theft light blinks continuously.

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