Key fob jammer for my Volkswagen car

Dear Community,

Our Volkswagen car has been broken into twice within 2 months using a Code grabber device to copy our car key code. I have found out that there are plenty of such devices around and that it is becoming an increasing problem as the key code can be easily copied via radio frquency waves transmitted at 433 Mhz.

I would like to know if it is possible to build myself a local Arduino based 433 Mhz jammer for my car to ensure that no one else can enter it using my copied car key information. The idea would be to switch it on overnight when the car is parked on the street.

Thank you in advance for your help.

Are you sure there isn't a better way to immobilize your car?

I presume what you are saying is that you want to disable unlocking of doors via radio, during the night.

Can you still get in using your key directly in the door.

Technically you could do something like, build an arduino with both a receiver and a transmitter, and if the receiver detects a signal that looks like pulses from your keyfob, it could turn on a transmitter (on 433Mhz) sending a bunch of random noise, which would probably prevent the receiver in the car getting the full data stream it needs to unlock the doors.

You may however find its easier just to remove the fuse that powers the central locking system.

You could use the Arduino to control a relay to disable the central locking circuit in place of the fuse.

My only concern is that if you lock the doors while driving and the arduino disconnects the power to the doors, you may not be able to exit the case in the case of an accident

So you may be better of just putting a manual switch in series with the fuse (or circuit if you can get to the wires)

BTW. You don't want to run the transmitter in the jammer all the time, because it will interfere with all sorts of other devices e.g. other people's cars, door bells, panic buttons, etc etc etc Which is why you'd need to have a receiver as well as a transmitter

However I still thing the switch / relay etc is better

The sort of jammer you're looking at building is technically not legal. I think you would be better off installing a security camera and a motion light. (both can be done with the Arduino)

Or maybe building something Arduino based that would set off an alarm and texting you when someone uses you key fob signal?

Good Luck!

How old is the car?
Most modern cars use a rolling code key fob to unlock the car, and these types of key fobs cant be copied by code grabbers
as the code changes everytime the button is pushed.
Unless your car has a very old style locking system, it would be easier to simply upgrade the locking system to a rolling code type.

it would be easier to simply upgrade the locking system to a rolling code type

I very much doubt that "simply" updating the firmware in both the internals of the car and replacing the keyfob with a matching rolling code generating fob is likely to be "easy"

I note the OP has not actually responded to any of the answers.

I still suspect that disabling the central locking circuit, by pulling the fuse at night is the easiest

mauried: Most modern cars use a rolling code key fob to unlock the car,

Dead right, so that is probably the case here.

mauried: and these types of key fobs cant be copied by code grabbers as the code changes every time the button is pushed.

Wouldn't bet on that. The "Keeloq" algorithm is apparently "security by obscurity"; I think it has been deciphered.

Hi, can you talk to your car dealer, see if it is possible to disable the RF system with a switch inside the car.

So at night you turn off the rf system, lock the car with the key.

In the morning unlock the car with the key then turn on RF system.

Tom...... :)

Simple, pressure the dealer to pressure the manufacturer to fix a security problem that they have in THEIR system.

Look at the date man, this dude is long gone. He probably wasn't genuine anyway and was probably just after an insight into how codes work so he could break them.

Grumpy_Mike: Look at the date man, this dude is long gone. He probably wasn't genuine anyway and was probably just after an insight into how codes work so he could break them.

Are you perchance responding to someone who has now deleted his post?

Because it now looks as if you are replying to an antique post.

The missing post was deleted because it was from a spammer advertising a key jammer. The same spam was also posted in another previously dead thread.

Pete