What Does the Security Indicator Light Mean?

What Does the Security Indicator Light Mean?

You can spot the Security Indicator light on your vehicle’s instrument panel. It usually takes the shape of a flashing key (for Nissan automobiles) or a car outline with a key inside it.

Its primary function is to initiate the immobilization of your car’s engine to prevent theft in the case of a compromise in its security system. The light is also illuminated when the ignition is off as well as when the OEM security is activated in other vehicles. However, if your vehicle’s engine is immobilized, do not jump to the conclusion that someone has attempted to steal your car. In most cases, engine immobilization is usually due to an error somewhere in your car’s security system.

Furthermore, when the key is out of the ignition lock and accessory position, the Security Indicator Light flashes, indicating that the alarm and immobilizer systems are operational. The security light should also illuminate momentarily before turning off when starting the automobile or when the key is in the “run” position. It is called a “bulb check” and is quite normal.

What to Do When Your Anti-Theft System Is On and Your Car Won’t Start

As mentioned earlier, the security indicator light might come on without any justifiable reason. By that, I mean that there doesn’t have to be an attempt to steal your car for the security indicator light to come on but your car will be immobilized anyway. So, if that’s the case, you’ll need to turn off the light manually. Below are some tips to manually turn off your car’s security indicator light:

Try Another Key

The immobilizer system might have a problem if the Security Indicator Light stays on when the key is in the “run” position and the car won’t start. In this scenario, the first thing to do is try a different key to see if it starts the vehicle. If a different key starts the car, the former key is either defective or the system can’t recognize it. But if a different key doesn’t start the vehicle and the security indicator light stays on, then the problem is with the system and will need to be inspected.

Another trick you might try is to start the engine with the key. Leave the key in that position for 10 minutes if the engine won’t start or dies after revving up. Then, turn off the ignition when the security light turns off, wait 20 seconds, and restart the engine.

Check the Battery

Another tip to try if your anti-theft system is on and your car won’t start is to check the battery. It could be dead or low on power and needs recharging. The car’s system will be unable to read the security code from off the key fob if the battery level is low or the battery is dead. Make sure the battery connections are secure. You can try jumpstarting the battery. There is a good chance that will resolve the issue.

Try the Door Trick

While opening the driver’s side door, insert your car key into the slot and hold it there for a few seconds after turning it. The idea is to override or get past the factory alert, thereby tricking the car’s system into recognizing the key in there as the original key. It doesn’t mean that you inserted a foreign key that you want your car to acknowledge. It’s like reinforcing the memory. This trick should work best with makes like Volkswagen, Mercedes-Benz, and BMW models. This can work even if the key fob is broken or the battery is dead.

Reset the Vehicle’s Computer

For a minute or two, disconnect the positive connection of the battery. Reconnect it afterward, making sure the anode and cathode terminals are securely connected. Doing this will reset the vehicle’s computer system, and the car should start after that. If that too fails, you can always use the factory alarm’s built-in kill switch to reset it.


The tips above are common ways to solve the “car won’t start” issue when accompanied by a security indicator light. Most car make and models will likely respond to these tricks. But if your car is more stubborn than the Taurus (I don’t mean Ford), then it’s time to employ the services of a certified automobile professional.

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