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Motor vehicle remote jamming is real

Motor vehicle remote jamming is real
31-05-13 / Staff Writer

Motor vehicle remote jamming is real

How is this possible?

Most modern remote controls use rolling-code technology, which means that the code command cannot be copied or cloned. The remote jamming that vehicle owners fall victim to is not the result of cloning or copying of the remote control.

Most modern remote controls work with radio waves that use an allocated radio frequency. The use of this specific radio frequency is prescribed by the Independent Communications Authority of South Africa (ICASA), the regulatory body for the South African communications, broadcasting and postal services sector. Most remote controls, including those for motor vehicles, gate and garage automation; operate on a frequency of 433MHz as issued by ICASA for this purpose. 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, at the gate or garage mechanism) to perform an action: lock or unlock the vehicle, or open or close the gate. 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, in other words, within each other's power range.

However, 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 pointed out that these remote control and jamming devices cannot unlock your vehicle. They can only stop your remote control from working properly.

Jamming of remote control devices can be compared with the situation of someone listening to two radio stations simultaneously, with the radio station that the person is not interested in closer and its volume higher than that of the other. Even the human brain will struggle to unravel the messages and follow any one of the conversations.

Does insurance cover these losses?

Depending on your insurance policy, claims for items stolen without any sign of forced entry into a vehicle will in most cases be rejected. It will definitely be rejected if the cover stipulates forced entry into the vehicle as a condition for a claim to be paid out.

What is the solution?

The manufacturers of motor vehicles are constantly trying to improve the security of vehicles. ICASA and other radio frequency controlling bodies worldwide have allocated another frequency band to be used for motor vehicles. Although this will effectively stop the blocking of the signal with a garage or gate remote control device, it will not stop blocking the signal when a similar remote control device is used in close proximity or when a jamming device is used. The following steps to help prevent jamming of remote controls are recommended:

The most important rule: Make sure your car is locked before you walk away. Manually check or test the doors and the boot.

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.


To summarise, household remote control devices, like those used for gates and garage doors, can block the signal of most motor vehicle remote control devices. Furthermore, "professional" jamming devices can block the signal of remote control devices that use a range of radio frequencies and technologies.

All vehicle owners must be aware that the remote control of their motor vehicles can be blocked. They should never assume that the vehicle is locked merely because the button had been pressed. It is important to make sure that the vehicle is indeed locked before leaving.

*This article was written by Fouch & Burgers at Business Against Crime SA (BACSA).

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