Security with 'Passive Key Entry'

[SuttonRider]

I've been reading on here and other places on the internet about the security of the 'Passive Key Entry' system and how easy it is to break into a car fitted with this system. Is this really a problem as the press would suggest? Is it possible to disable the PKE system and just rely on pressing a button on the key fob? I'm also aware about moving or locking access to the port.

Also, using a Faraday bag may help while the car is parked at home, but its a bit of a faff to use when out and about. With the fob tucked away in the bag does it have any range at all, will it still work even if very very close to the car?

[dansallis]

Yes it is a problem, and (probably unsurprisingly) very easy to do.

As far as I am aware, there is no way in which you can disable the PKE system without having to go through loads of re-programming.

Thieves only get away with this when people keep their keys near the front of their house, where their vehicle is right outside. Fortunately, the key transmits a low-frequency radio signal (which is what the thieves use to steal your car), which can be blocked completely by metal.

So, by putting your keys in a small metal box or metal key cabinet will make it impossible for anyone to steal your car without actually having the key.

[Dee_82]

There are a number of ways people can bypass the system, have you ever park net to another car in a car park? Everything they need to know is transmitted back and forth, they follow you home Job done. The only way to delay them is a dead switch in the car, if someone wants it, they will get it.

[Dee_82]

You might be better installing a tracker, won't stop them kicking it but you can at least trace where its gone....right up until it ends up dismantled and sold for parts at th docks

[SuttonRider]

1 hour ago, dansallis said:

Yes it is a problem, and (probably unsurprisingly) very easy to do.

As far as I am aware, there is no way in which you can disable the PKE system without having to go through loads of re-programming.

Thieves only get away with this when people keep their keys near the front of their house, where their vehicle is right outside. Fortunately, the key transmits a low-frequency radio signal (which is what the thieves use to steal your car), which can be blocked completely by metal.

So, by putting your keys in a small metal box or metal key cabinet will make it impossible for anyone to steal your car without actually having the key.

I think you meant its a low-power radio signal as the frequency used is 433.92MHz which is Ultra High Frequency, However I take your meaning and thanks for the input, it seems the PKE will have to stay.

[alexp999]

Any Ford dealer can turn it off for you.

[dansallis]

1 hour ago, SuttonRider said:

I think you meant its a low-power radio signal as the frequency used is 433.92MHz which is Ultra High Frequency, However I take your meaning and thanks for the input, it seems the PKE will have to stay.

Yep, you are absolutely correct! I was getting mixed up with the key transmission signal and the vehicle transmission signal. It is the vehicle signal that transmits LF to detect when the key is in proximity, which then activates the key. (I believe).

If you can find how/where the vehicle transmitter is, then I guess you could remove it and the PKE system would be ceased. But you'd be playing with fire (as well as your warranty lol!).

[SuttonRider]

 

Thanks for the info alexp999 its booked in for its first service at the beginning of March I may get it done then.

That's interesting dansallis, I didn't know about the LF signal. Do you know just how the whole system works. I have a radio that can receive 433.92 and I took it out to the car and listened to what was going on. If you push the lock / unlock buttons on the fob there's a burst of data for about half a second, but if you use the PKE it's just a few milliseconds of data. I'm intrigued as whats going on. (I know, I need to get out more).

[dansallis]

The Keyless Entry System uses a High Frequency (HF) radio transmitter in the keyfob that sends short bursts of encrypted data to the vehicle which will decrypt it. The vehicle then unlocks the corresponding door based on which keyfob button you pressed.

This is slightly different to the Passive Keyless Entry System that doesn't require any action on the keyfob at all. It works based on a Low Frequency (LF) radio signal (typically 21.8 kHz, 125 kHz or 134 kHz) that is transmitted from the vehicle by several LF emitter antennae, usually found in or around the door handles and boot handles. This is only able to send a signal a couple of metres unlike the HF signal which can travel up to 100m.

In our versions of the PKE System we are required to press a button on the door or boot which begins the process by emitting the LF signal, creating a field of a couple of metres around the vehicle. If in range, the keyfob will detect this signal and transmits the HF signal (again in short bursts) which will then unlock the corresponding door/doors based on which button on the vehicle you pressed.

Other versions of the PKE System, which unlock the vehicle as you walk up to it, emit the LF signal constantly (periodically) instead of only once a button on the car is pressed.



Below is a quick outline of what happens when a thief steals a vehicle in this manner (THIS IS NOT A GUIDE):

• Stand next to the vehicle.
• Press the button on the door handle (beginning the emission of the LF signal).
• Boost the signal using a cheap (probably DIY) battery powered LF signal booster.
• This will then be able to find the key within the house (providing there is nothing in the way blocking the signal).
• The keyfob will then think it is within proximity of the vehicle and send out its normal HF radio signal, unlocking the doors.
• This process is repeated for the ignition button.
• However, the keyfob must be detected inside the vehicle, so they replicate the keyfob's HF signal (from the ignition button press) whilst inside the vehicle.
• The vehicle then starts.

I am not sure why there is a difference between the burst length when pressing the buttons on the keyfob and on the door. I can only assume it is to distinguish the difference between the two (for the vehicle's sake) or for encryption purposes.

I really hope I don't get banned for this post.

DISCLAIMER: THIS IS NOT FROM PAST EXPERIENCE! 

[SuttonRider]

Thanks dansallis, that's a great answer, I now have a much better idea of how it all fits together. I've taken a copy of it and saved it away, if you did want to delete it on here. I can see how it may be regarded as sensitive. Once again thanks.

[biff55]

all of this.......

 

just to replace this....

 

 

its what the car industry marketing boys like to call "tech progress"  :-D

ridiculous lol.

 

[avi]

 

Lol - The bottom line is if someone wants to steal a car they will find a way to get it irrespective of keyless or keyed entry.  Unfortunately, I've been the victim of car theft and that was a car with a real key and immobiliser.