Author Topic: Keys And Other Antitheft Technology Used In Cars And Motorcycles  (Read 193 times)


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Several different technologies have been used over the years to lock your car and prevent someone from driving away with it. From the very beginning up until around 1986, all cars and motorcycles used simple mechanical keys to lock and unlock mechanical locks installed in your vehicle. The keys were either single sided meaning cuts were made on the key on only one edge and could only enter the lock one way, or the key was double sided meaning cuts were made on both edges of the key and could enter the narrow key way in one of two different positions. The double sided key made it easier for the user and was often referred to as a convenience key.

The mechanical lock technology varied depending on the make of the vehicle. The types of mechanial locks used on cars and motorcycles are either wafer or pin tumbler locks. Often times a side bar was added to make it more secure as seen on many General Motor's vehicles. These type of mechanical locks are still used today.

Around 1986 General Motors added an electronic resister to the key blade on keys used for several different GM models. The resister could be 1 of 15 different resistance values and the car was configured to recognize only one value. If you used a key with the wrong resistance value the car would not start even though you might be able to turn the ignition lock. This system was called VATS, Vehicle Antitheft System. The VATS system added another level of security and was successfully used for more than a decade to help prevent car theft. The VATS system was in use from around 1986 to 2002 and was only found on General Motors vehicles.

In 1995 European insurance companies succeeded in pressuring countries in Europe to pass laws requiring all new cars sold in Europe to be equipped with a transponder system. The requirement forced auto manufactures to use transponder systems on cars sold around the world, which is why you see transponder systems used on all cars and trucks sold in the United States today. A transponder is an electronic device usually installed in the key and has the ability to communicate with the vehicles computer. The cars computer and the key can pass information between each other to verify that the right key is being used to start the car. If you insert a key into the ignition lock that can operate the lock in a transponder equipped vehicle, but has the wrong electronic information, the vehicles computer will tell the immobilizer system to disable the car and not allow it to start. The immobilizer is an electronic part of a vehicles antitheft system that disables the car when the wrong key is used. There have been several different algorithms used over the years with ever increasing complexity to make transponder systems a more secure. The transponder system is still in use today and has allowed auto and motorcycle manufacturers to almost eliminate the mechanical key and lock in some higher end vehicles.

Even though electronics is becoming more popular in automotive and motorcycle security, the simple mechanical key and lock are still in use today. Many single and double side keys have been replaced with another type of mechanical key often referred to as a high security key. The high security key has the cuts milled into the side of the key instead of on the edge. I'm not sure why the key is referred to as "high security." Maybe because it's new and the knowledge to defeat the technology isn't as widespread? I believe barrel keys and locks used on so many candy and coke machines and also on Harley Davidson touring motorcycles were once called "high security" when they first appeared, but are no longer called that. I guess every new antitheft technology is considered high security until someone figures out how to defeat it.

Below is a list of descriptions and their definitions used to describe modern day electronic vehicle antitheft systems:

Passkey Systems

I think "Passkey" orginated with General Motors and was primarily used to refer to the GM VATS system, which I described earlier. I've also seen it used to refer to a transponder system or key.

Keyless Entry Systems

Keyless Entry is used to describe automotive remotes used to unlock and lock your car doors and trunk to gain access to your vehicle. Some remotes also have panic buttons to set off the car alarm, and a remote start button to start your vehicle at a distance. Keyless Entry is also used to describe a key pad placed on the car door which allows the driver to input a code and open the car doors. I've seen these key pads on many Ford vehicles.

Smart Keys or Proximity Key

Smart Keys look like remotes and have the same remote features, but are also equipped with a transponder used to communicate with the cars computer. On some smart key systems a person inserts the smart key into a slot in the dash and presses a start button to start the car. On other higher end smart key systems the person with the smart key simply needs to be within a certain distance from the car for the computer to recognize the key and allow the person full access to the vehicle. Smart key systems eliminate the need for mechanical locks and keys. Smart Keys use radio frequency signals to communicate between the smart key and the vehicle. A car can be divided into zones allowing the car to grant access to different areas of the car depending on the location of the driver and smart key. I believe later model Harley Davidson touring motorcycles use some type of smart key. Often times the vehicle manufacturer will place a mechanical door lock on the drivers door and hide a mechanical key blade in the smart key to use in case of an emergency.

Alarm Systems

Some cars and trucks come equipped with alarm systems from the factory. Most motorcycle models don't have factory installed alarms, but I believe it is an option on Harley Davidson touring models. Alarms can be passive or active. Passive alarms switch on and off automatically and active alarms require input from the driver. When someone tries to break into a car and the alarm goes off it usually beeps the horn on and off while flashing the high beam headlights and hazard lamps. Some alarms have a built in siren that goes off. Alarms can come with different features such as ultrasonic sensors to detect movement inside the car or motion detectors to monitor the vehicles tilt.

Click on image to enlarge:

The first key is GM high security key with cuts milled into the side of the key, and a keyless entry remote. There is a transponder chip embedded in the key head or bow. The second key is a Ford double sided key with cuts on both edges of the key. It is a regular key with no transponder. The third key is a Chrysler single sided key with cuts on only one edge of the key. It is a regular key with no transponder. The fourth key is a Mercedes Benz smart key that is also a keyless entry remote.

Click on image to enlarge:

This is an aftermarket VATS key for GM vehicles. This key is a single sided key, but they also make a double sided VATS key. You can see the resister embedded in the key blade.

« Last Edit: October 14, 2020, 04:13:46 PM by adminjoe »
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