How to Protect Your Car from Radio Jammers

by Beyond

This past September, an interesting bypass of car locks was believed to have occurred in Surrey, England.  Police in Surrey theorized that a gang of car thieves were, and possibly still are, utilizing radio jammers to help gain entry into vehicles.  According to a local resident, who perhaps was nearly a victim, he was unable to lock his car with his remote in the presence of an individual dressed in unseasonably warm clothes.  When this individual was no longer around, the car and remote cooperated as if nothing out of the ordinary had ever happened.  Police believed that the individual was dressed in unseasonably warm clothes to conceal a radio jammer.  When an intended target tried to lock his/her car, the jammer, already turned on, would prevent communication between the remote and the car and thus prevent the car from being locked remotely.  The car owner would unknowingly walk off leaving the car unlocked, allowing the thieves uninhibited entry.  Ingenious, to say the least.  Theoretically there's nothing preventing this from happening, but realistically?  I'd like to see a bit more proof than just one testimonial before I' m convinced.  Nevertheless, it's possible, and you, I, and everyone else could be a victim.  Let's look at this vulnerability a bit more in depth and discuss a few ways that we can all better protect ourselves and our property.

First, let's do an experiment.  You're going to need a car remote and Internet access.  Look on the back of the car remote and find a number listed to the right of the FCC ID.  Now, point your browser to the FCC's ID Search database which is found at:  This database contains public information related to a searchable FCC ID.  Next, we're going to input the FCC ID into the form found on the previously linked page.  In my example, I'm going to use my Ford Ranger remote.  Its FCC ID is "CWTWBIU345".  Don't worry; it's not unique or linked to my VIN.  I share it with hundreds of thousands of other people.  When I hit submit, I get some basic information about my device such as its manufacturer, Alps Electric Co., Ltd., and their address.  I also can get some reference material, such as photos of the device's internals or test reports, by clicking "Detail" under "Display Exhibits."  That's all well and neat, but what we're looking for is our device's operating frequency.  You can find that by looking at the last two columns from our initial search return: Lower Frequency in MHz and Upper Frequency in MHz.  In our case, along with just about every vehicle on the road, its 315 MHz.  Toyota, Lexus, Mercedes, Chevrolet, etc. all use remotes manufactured by separate companies, such as Alps, that utilize the same 315 MHz as required by the FCC in the United States.  Now, I'm sure you're thinking, "But Surrey is in England, well beyond the jurisdiction of the FCC!"  Right, but when your biggest customer, the United States, requires a certain frequency on one of your products, you're going to conform to that request and your entire product line is going to reflect it.  Simple business strategy, but I digress.

A quick search on produced a jammer capable of operating on the 315 MHz frequency at a range of between 50 and 100 meters for roughly $35 USD.  I'm sure a more intensive search could produce a cheaper and perhaps more reliable device, but you get the point: what they need to prevent you from locking your car via a remote is easily accessible and not very expensive.  It's also not exactly rocket science to operate, either, which probably explains why they're in this line of work, if you want to call it that.

So how do you protect yourself, your friends, and family from this?  Exercise common sense.  If you don't hear your door locks "move" into the locked position after pressing the corresponding button on the remote, try again.  Still nothing?  Then manually lock your doors.  A jammer isn't going to prevent you from manually locking each door or pressing an "All Lock" button in your car.  It's not going to unlock them either once you leave.  If your car remote doesn't work, don't panic and don't become paranoid.  There's usually a common explanation to the above scenario: a low battery.  Your car is already locked at this point; even if someone is trying to jam your remote in the area, you've already thwarted their attempts.  Take your remote to the local auto parts store when you get a chance and have them check your battery's strength.  Breathe a sigh of relief when they tell you it's dead and you didn't just almost become the latest victim of a radio jamming gang.