Does Having a Key Fob Mean You Have a Security System?

While virtually every car security system comes with some type of key fob (or smartphone integration via telematics), the fact that your car has a key fob doesn’t necessarily mean it has an alarm system. There are some easy ways to tell, however.

How to Identify Aftermarket Security Systems

If the fob is aftermarket, then it almost certainly came with an alarm system. Most new cars with fobs don’t have alarms, although they may have a variety of security features. In either case, you may want to check all of the paperwork you received when you bought the car for the owner’s manual and any documentation on aftermarket accessories.

Used Cars With Aftermarket Key Fobs

If you bought a used car that came with an aftermarket key fob, then it’s a pretty good bet that it’s tied into some kind of security system. However, the situation may be a little more complicated than that.

Key fobs are typically used to arm and disarm security systems, lock and unlock doors, and activate remote starters. Some aftermarket security systems combine all three functions into one system that uses a single key fob.

Figure Out Your Key Fob Situation

Examining your key fob and taking a look under the hood will typically reveal what type of situation you’re dealing with. If the key fob only has two buttons, and all they do is lock and unlock the doors, then your car probably has aftermarket power door locks and nothing else.

If the key fob has another button that causes the horn to honk when you push it, or if the horn honks when you push the door lock button, you may have a car alarm, or it may simply be designed to make people think you have an alarm.

Simply opening the hood of your car and looking around will usually reveal whether or not your car has an aftermarket alarm system installed. The siren is the most obvious component, and they are almost always mounted in the engine compartment, so that’s what you’ll be looking for.

How to Identify OEM Security Systems and Features

Most new cars come with key fobs that can be used to lock and unlock the doors, but that doesn’t mean the vehicle also has a security system, let alone an alarm.

OEM alarm systems are relatively rare, so if you’re interested in a functional alarm system for whatever reason, you’ll want to do a little research instead of just assuming that you’re set. In that case, the first place to look is your owner’s manual.

If the car came with an actual alarm system, or if it was even an option, then the manual will say. If you can’t find the manual, then you may want to consider reading the vehicle identification number (VIN) and contacting a local dealer. They should be able to determine which options the vehicle came with from the VIN.

Other Security Features

Although OEM alarms are relatively rare, many new vehicles do come equipped with a variety of security features. If your key fob is capable of locking and unlocking the doors, and it has another button that allows you to start the engine remotely, it may include some type of security feature that’s designed to deter theft.

For instance, it may have an automatic shutdown feature that turns the engine off if the vehicle is driven out of range of the key fob. In fact, in some places, it’s actually illegal to use a remote starter without that type of functionality.

Of course, some security features don't require key fobs at all. For instance, it's entirely possible that you might purchase a used car that's equipped with LoJack, which is a vehicle tracking system that doesn't have any use for a key fob.

OEM and Aftermarket Security Systems and Key Fobs

In any case, the simple fact that your car has a key fob doesn’t really tell you anything other than that it has a key fob. Determining whether it is aftermarket or OEM will give you a better idea of what you’re dealing with, as will simply pushing the buttons to see what they do.

Matters will be greatly simplified if you can locate your owner’s manual, speak with a helpful dealership, or obtain the model of any aftermarket units to research them further.