Beware of remote jamming which puts your car at risk

 ·27 Jun 2015

Police in Centurion recently reported a spike in petty theft of goods out of vehicles in parking lots, and car remote jamming is suspected in many of these cases.

Large shopping centres like the Brooklyn Mall in Pretoria are also warning customers to be vigilant and to ensure their cars are locked before they leave the parking lot.

Car remote jamming in South Africa stretches back many years. In October 2013 the Eastern Cape police warned that criminals were targeting motorists by overriding vehicle remote locking systems.

The recent rise in crime where car remote jamming is suspected means that an overview of how this crime works, and what can be done about it, is valuable.

The video below provides a real-life example of how criminals use car remote jamming to steal possessions.

How car remote jamming works

Fouche Burgers from Business Against Crime SA explained that criminals can block, or jam, the locking signals of remote locking devices on vehicles.

Most modern remote controls use rolling-code technology, which means that the code command cannot be copied or cloned.

However, because most modern remote controls work with radio waves that use an allocated radio frequency, they are vulnerable.

The use of this specific radio frequency is prescribed by Icasa.

Most remote controls, including those for motor vehicles, gate, and garage automation operate on a frequency of 433MHz. Understandably, this frequency has become very busy.

When a remote control button is pressed, it sends a message (command) on the allocated frequency to a receiver (in the vehicle) to perform an action: lock or unlock the vehicle.

At the other end, the receiver is “listening” for a specific message that it can interpret to perform a required action.

When a button of another remote is pressed in close proximity, the receiver receives (hears) two messages simultaneously.

The two messages are consequently scrambled, the receiver cannot interpret the message, and no action is initiated (the vehicle’s doors are not locked).

Remote controls operating on the same frequency can influence each other’s messages if they are operated in close proximity.

According to Outsurance, thieves often use a standard 400MHz gate or garage remote control to jam the signal sent by a car remote control.

To make matters worse, there are “professional” jamming devices available that function on a range of frequencies and that have much higher signal power.

These devices can influence a vehicle’s remote control from a much greater distance and can even interfere with remote controls that use different frequencies and technologies.

It should be noted that these remote control and jamming devices cannot unlock your vehicle. They can only stop your remote control from working properly.

[Also see: The science of car jamming]

Car remote jamming infographic

Car remote jamming infographic

What you can do about car remote jamming

Burgers and Kingdom Electronics suggest the following steps to prevent the jamming of remote controls.

  • The most important rule: Make sure your car is locked before you walk away. Manually check or test the doors and the boot.
  • Never push the remote locking while walking away from the vehicle.
  • Always be aware of your surroundings and keep a sharp lookout for suspicious-looking people and activities.
  • Report suspicious-looking people to security or move your car to a safer place.
  • Never leave valuables in your car.

Some companies are also selling early warning car alarm jammer systems to alert motorists if there are jammers active in the area.

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