Do your remote controls provide you with the security that they should?

What this article covers

What “signal jamming” actually is — and what it is not
How rolling-code remote technology works in vehicles and access automation
Why the 433MHz frequency band is commonly used in South Africa
How signal interference can occur in busy radio environments
Why no remote brand is immune to interference
How criminals may exploit user assumptions rather than technology flaws
Practical steps you can take to ensure your vehicle or property is properly secured

What’s important to know?

Reports of so-called “signal jamming” have caused confusion and concern among vehicle owners and access-control users.
Some media articles and forwarded emails incorrectly suggest that certain remote controls cause criminal jamming.
In reality, most incidents are linked to signal interference, not malicious remote devices or specific brands.
Understanding how remote control technology works is key to preventing theft and avoiding misinformation.

Today, we’ll be looking at a rather contentious issue that’s been garnering a lot of media attention lately, so-called “signal jamming” by criminals.

A recent article that appeared in an Mpumalanga newspaper and various emails that have been doing the rounds have been causing quite a stir.

The article detailed how some remote controls may interfere with vehicle remote controls, which arm the car’s alarm and opens and closes the central locking systems. It is claimed that these remotes are responsible for jamming the vehicle’s remote control frequencies, thereby making it easy for thieves to help themselves to the contents of a car once an unsuspecting driver walks away. The car owner presses his remote control to lock his car, assuming his car is locked and the alarm is armed. Only to return to find all of his possessions left safely in his ‘locked’ car missing.

There has also been a fair amount of finger-pointing at particular brands of remote controls as being the culprits. There is also a huge amount of misinformation and confusion surrounding this issue, so CENTURION decided to clarify the misconceptions and help you understand how these incidents may have occurred, and what to do to ensure that it never happens to you.

Let’s start by delving into the technology that resides inside high-security remote controls. Any modern high-security remote control should have rolling-code technology. Essentially, this means that every time that you press the button on your remote control it changes it’s code (or identity) and the receiver in the car, gate motor, etc. that it usually talks to, correspondingly rolls its code to stay in synchronisation.
This means that your rolling-code remote control for your car or access automation system cannot be copied or cloned – providing you with great peace of mind.

However, the vast majority of vehicle manufacturers, and other manufacturers of remote controls such as gate and garage automation, produce remote controls that operate on a frequency of 433MHz issued by ICASA, the regulator for the South African communications sector. This results in this frequency being very busy with many, many remote controls utilising this airspace.

Typically what can happen is if two remote controls operating on the same frequency are activated simultaneously and within range of each other, the signals that they are transmitting can interfere with one another. The result could mean that the receiver doesn’t recognise the ‘strange’ interfered-with signal from its know transmitter remote control. What happens? Nothing – the receiver simply doesn’t react. This is fine if you’re trying to open your gate – your home is still secure, and you just press your remote again and your gate opens.

Now you can imagine that in the instance of locking your car you would want to know that your car really is locked when you press your remote control. If a car owner in your vicinity presses their remote at the exact same instant as you, or for some reason is holding their remote button down,for example to automatically open all of their car windows before getting in to let all of the hot air out (nice feature!), then this will certainly interfere with your car’s remote control signal.

This doesn’t have to be another vehicle remote control; it could be any type of remote control operating on the same 433MHz frequency that can cause interference.

This is why most cars will give a visual and/or audible verification on receiving a remote control signal. Typically the indicators will flash, or the car will beep, once for locked and twice for unlocked.

The bottom line is that any remote control from any manufacturer is vulnerable to being jammed, or having its signal interfered with. Thieves may try to take advantage of this by flooding an area with remote control signals in the hope that you might simply walk away from your car without actually checking that it did lock and arm.

So please safeguard yourself and look for the telltale flashing indicators, or listen for the confirmation beep, which will reassure you that your car is locked and your goods are safe.

For further information or advice concerning remote control security please feel free to call any CENTURION branch or our Customer experience centre on Whats App

+27 (0)83 650 4010

Frequently Asked Questions

What is signal jamming?

Signal jamming is when a remote-control signal is blocked or disrupted so that the receiver does not respond. In most real-world cases, this is caused by signal interference, not deliberate criminal equipment.

Can gate or garage remotes jam car remotes?

No. Gate, garage, and vehicle remotes do not actively jam each other. They may operate on the same 433MHz frequency, which can result in temporary interference if signals overlap.

Are certain remote brands responsible for jamming?

No. There is no evidence that any specific brand causes signal jamming. All remote controls using shared radio frequencies are equally susceptible to interference.

What is rolling-code technology?

Rolling-code technology changes the remote’s transmitted code every time the button is pressed, preventing cloning or copying. This makes modern remotes secure against replay attacks.

Does signal interference unlock my car?

No. Interference does not unlock vehicles. It prevents the lock command from being received, meaning the car simply remains unlocked if confirmation is not checked.

Why do cars flash or beep when locking?

Visual flashes or audible beeps confirm that the vehicle successfully received the lock signal. If you do not see or hear confirmation, the vehicle may not be locked.

Can criminals exploit signal interference?

Yes. Criminals may attempt to exploit human behaviour, hoping drivers walk away without confirming the lock—not by hacking or breaking rolling-code security.