Key fob goes to sleep.

[old man 2]

 Maybe a bit of useless info, but I've been a bit obsessed with car security since since I bought my last car, a stealable, black Hyundai Tucson.

On that car the the key fobs went to sleep after a few minutes of lack of movement and stopped sending signals to the car, thereby preventing relay theft. I don't know exactly how long it is before the fob goes to sleep, but I left my fob undisturbed for 7 mins which was long enough.

I asked the sales person when I picked up my car on Friday if my fobs did the same, but he didn't know, so today I experimented and the answer is yes yes they do - I'd have been disappointed if they didn't in this day and age.

 Yes I know there's a way to disable keyless entry via the fob and this applies to my car and so I can't speak for other years and models, but I'd like to think that any model coming out of the factory recently will have the same feature.

I don't rely solely on this feature and keep my fobs in a Faraday box and generally use a Stoplock as well, but it's good to know that my fobs have this feature.

 

 

[old man 2]

 Apologies if the above post is a bit garbled. Not sure if it's my fault or my laptop, however I expect you get the gist.

[ColinBarber]

There wasn't a single date when they changed over to sleeping key fobs, it is model dependent, but it is around 2022/23.

It took them longer than other marquees to make the change.

[Hayzee]

On 11/17/2024 at 5:31 PM, old man 2 said:

I don't know exactly how long it is before the fob goes to sleep, but I left my fob undisturbed for 7 mins which was long enough.

I tested mine and they slept between 3 and 4 minutes, hence I don't feel the need to have the keys in a pouch.

[old man 2]

1 hour ago, Hayzee said:

I tested mine and they slept between 3 and 4 minutes, hence I don't feel the need to have the keys in a pouch.

 I keep mine in a Faraday box because I don'y fully trust the electronics involved, plus there was a member on the Tucson forum who tested his fobs quite rigourously and found that one of them wasn't as reliable as the other one.

Better safe than sorry in my book.

[Hayzee]

With respect we could say that about safety critical electronics too

23 hours ago, old man 2 said:

Better safe than sorry in my book.

 

[old man 2]

6 minutes ago, Hayzee said:

With respect we could say that about safety critical electronics too

 

 Sorry, I don't understand your point ?

[Hayzee]

5 minutes ago, old man 2 said:

 Sorry, I don't understand your point ?

It's just that Lexus introduced UWB fobs and auto sleep fobs so that we don't need to deploy other means. But I understand your choice.

[old man 2]

30 minutes ago, Hayzee said:

It's just that Lexus introduced UWB fobs and auto sleep fobs so that we don't need to deploy other means. But I understand your choice.

Ah I see. As we all should be aware, electronic and computerised  components are prone to glitches and I don't trust them to work properly for 100% of the time. Keeping my fobs in a Faraday box is just an extra, easy precaution to help keep my hard earned new car as safe as I can.

I know that if thieves want my car, they'll have it eventually, but I'm certainly not going to make it easy for them !

[Lexusjim]

I may be wrong however I think the key fob only 'goes to sleep' if it is stationary....which would mean it is still active as you walk round Sainsbury's,  in the park, or a restaurant (until you are escorted to your table)

I use these:

https://www.amazon.co.uk/gp/product/B09BMJL1DR/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Not expensive and also give the key some protection should I drop it

 

[ColinBarber]

1 hour ago, Lexusjim said:

I may be wrong however I think the key fob only 'goes to sleep' if it is stationary

That's correct. The key fob would need to be stationary for a few minutes before it goes to sleep.

The scenario you suggest is possible but unlikely, unless you have a vehicle with UWB keys (e.g. an NX supplied mid 2023 onwards) when that becomes impossible. With conventional keys the vehicle assumes your proximity by signal strength (which is defeated by a relay attack), with UWB the vehicle knows proximity because it precisely measures time of flight - if the signal is relayed the system knows the key isn't within a short distance of the vehicle and won't unlock.

[old man 2]

Quote

which would mean it is still active as you walk round Sainsbury's,  in the park, or a restaurant (until you are escorted to your table)

 True, but even I can't be bothered to carry a Faraday bag around with me and put my fob in it all the time. There's no point really as nobody is going to follow you around a supermarket with a signal reader and then transmit to an accomplice who's near your car.

I am however careful when leaving and locking the car as there could be someone nearby with a signal reader. Also and I don't know if this still happens on modern cars, thieves had equipment that would block the signal from your key to the car when you pressed the LOCK button thereby preventing the car from locking, then they'd steal the contents of the car or the car itself. How many people have you witnessed getting out of their car and pressing the fob lock button whilst walking away, so therefore not actually knowing if the car has locked or not.

Probably teaching you to suck eggs here Jim, but have you tested your bags to ensure they are actually blocking the signal. I've had bags that will work with one car, but not another as the signal being emitted was stronger. These bags are not created equal, plus they do wear out over a period of time.

Quote

with UWB the vehicle knows proximity because it precisely measures time of flight - if the signal is relayed the system knows the key isn't within a short distance of the vehicle and won't unlock.

I didn't know that, but I will continue to keep my fobs in a Faraday box whilst at home.

[Lexusjim]

3 hours ago, old man 2 said:

have you tested your bags to ensure they are actually blocking the signal.

I have indeed.....in fact, they get inadvertently tested all the time when try to get into the car, only for it to remain locked and me to realise the key is still inside the pouch.....🙄

Part of the reason they start to leak signal is that people put their housekey inside as well, and the sharp key edge tears the lining....something I am careful not to do...

 

[Grumps]

I generally jut touch the door handle to lock the car. That way you can see the mirrors fold and know its locked.