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. 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. The use of this specific radio frequency is prescribed by Icasa.
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.
So even if you lock your car with your remote stay with your car and check manually that it is indeed locked before you walk away.