Proximity Locking Questions

[Todd]

Given that car key frequencies can be grabbed out of the air by bad actors, I've never been a fan of pushing the button on the remote to lock/unlock.

What I've always used on my other cars is the proximity function of having the key in my pocket when next to the car, and grabbing the handle.

What I can't figure out on my 25 5BW is how to set it up so that I get an audible signal when I am touching the handle to lock the car. I am never sure the car has locked on my 5BW with the handle touch, there is no audible feedback.

The only way I can set up an audible receipt is with the auto lock/unlock function enabled, which happens when there are several feet between me and the car.

That begs the question: how does that far-away proximity function work? Is there a frequency exchange between the key and car that can be grabbed by a bad actor?

(and if so, maybe that's even how the close proximity lock/unlock even works, and I've been ignorant of that all these years)

I'd love to find a way to just have the car beep when I manually touch the handle with the key in my pocket.

 

[AdamUCF]

Proximity is still RF. I'm not sure of the exact implementation but that's why some people put their keys in faraday boxes because that functionality can theoretically be used to steal a car from a driveway while someone is inside sleeping.

Maybe it's because I don't live in a real high crime area but these types of things are quite rare and I just don't worry about it. Sure it would absolutely suck but this is what insurance, OnStar tracking, etc are for. Drive and enjoy your car and use the features of the wireless key.

 

[dribs15]

Set your side view mirrors to fold automatically when the doors lock. It's not an audible beep, but you get that visual (mirrors folded = doors locked)

 

[Todd]

Set your side view mirrors to fold automatically when the doors lock. It's not an audible beep, but you get that visual (mirrors folded = doors locked)

I like it, thanks for the idea.

This solves the issue when my backpack isn't in the car when in my garage and the damn thing is locked. I'd rather have manual control over the lock function.

 

[BimmerFan]

I can hear the doors lock 80% of the time. I can also see the door lock light most of the time.

However, although all of that stuff about thieves grabbing the codes and stealing your car are true, I agree with Adam that it's just not worth getting all worried over, just keep your insurance paid up.

 

[bloominguez]

Given that car key frequencies can be grabbed out of the air by bad actors, I've never been a fan of pushing the button on the remote to lock/unlock.

What I've always used on my other cars is the proximity function of having the key in my pocket when next to the car, and grabbing the handle.

What I can't figure out on my 25 5BW is how to set it up so that I get an audible signal when I am touching the handle to lock the car. I am never sure the car has locked on my 5BW with the handle touch, there is no audible feedback.

The only way I can set up an audible receipt is with the auto lock/unlock function enabled, which happens when there are several feet between me and the car.

That begs the question: how does that far-away proximity function work? Is there a frequency exchange between the key and car that can be grabbed by a bad actor?

(and if so, maybe that's even how the close proximity lock/unlock even works, and I've been ignorant of that all these years)

I'd love to find a way to just have the car beep when I manually touch the handle with the key in my pocket.

I'm not following the question. You're not a fan of the signal getting intercepted when you press the button but you're okay with a continuous broadcast??? I feel like I'm missing something.
>> EDIT, per leres' post below. "... but you're okay with leaving the fob in a state where it will respond to a relay attack any time someone cares to try?"

I do use a Faraday pouch for my Cadillac keys, that's common best practice nowadays. With my "need to press the button" key (on my Ford) I don't bother, because it's not continuously broadcasting, no need (as far as I know). And with my Toyota keys, I can disable and reenable the proximity sensing very easily--more companies should do it like they do. I think there is a way to do this with Cadillac but I don't remember it (I vaguely recall that it wasn't as easy as the Toyota keys, happy to be corrected).

Also, as far as I can tell, the re-locking is more a function of time than proximity. Many times I get out of the car in my garage and am still close to it, and the car re-locks in the same amount of time (as far as I can tell) as if I had walked away.

 

[nordique14]

You can also lock using the myCadillac app on the phone or watch. I assume that sends a signal over the 5G network. The app/watch will tell you when the locking (or unlocking) process is complete.

 

[jbawden]

I just peak around at the indicator lamp on the side mirror for the light blink confirming that its locked.

Faraday user here too. It's literally .73 of a second to remove or replace the keys in the pouch. Seems a lot less time and hassle than dealing with insurance, a shitty insurance payout (not to mention rates going up or getting cancelled), trying to source a new BW and the transaction costs associated with it, and whatever feels the violation creates on an individual level. Not saying this will prevent theft, but it's impossibly simple step to hopefully slow or stop less motivated thieves.

 

[leres]

I'm not following the question. You're not a fan of the signal getting intercepted when you press the button but you're okay with a continuous broadcast??? I feel like I'm missing something.

The fob does not transmit continuously for keyless entry (or push-to-start). When activate the door handle switch (or push the start button) the car sends a (short range) RF challenge to the fob and it responds (also short range). I know with my C6, there are four antennas used for this (one for each door, one in the dash, and one at the rear hatch).

What the bad guys are doing is bridging the challenge/response (over a new RF channel or the internet). It's called a relay attack. As mentioned, you can defeat this attack by putting the fob in a faraday bag, which is a good place to store your spare fob(s).

In theory I believe the attack can be defeated if the car measured the round trip time for the challenge/response; the one-way propagation delay for RF (in atmosphere) is about 1 us/ft, so 5 ft is about 5 us and 50 ft is about 50 us. I haven't heard of any system that does this yet.

 

[Finally-a-V]

They want it, they can have it. I just don't want to see it again. It'll be trashed. I'll take the insurance money.

 

[jbawden]

Getting a stolen car back is adding a layer that I wasn't including, but could not agree more. I guess I'm a lot more adverse than some to the hassle and out of pocket costs to get a replacement.

 

[jwolf99]

According to the manual, you can disable and re-enable keyless entry by holding the lock and unlock buttons on the key fob for four seconds. If this actually disables the RF transmission capabilities to unlock the doors and trunk, this should defeat those capabilities in relay attack, at least insofar as a thief being able to unlock the doors and trunk. What I don't know is whether the capabilities of the thieves may be advanced enough such that they can re-enable keyless unlock with their equipment as if they are actually holding lock + unlock on the fob for four seconds.

 

[CBH]

Auto lock is the feature that makes keyless entry worth it. Just set it to auto-lock (agree that it seems to be a function of time rather than proximity), and then set the indicator to lights only. Nothing is worse than getting out of the car in your own garage, only to be started when the horn blares just as you reach the door to the house.

 

[leres]

According to the manual, you can disable and re-enable keyless entry by holding the lock and unlock buttons on the key fob for four seconds. If this actually disables the RF transmission capabilities to unlock the doors and trunk, this should defeat those capabilities in relay attack, at least insofar as a thief being able to unlock the doors and trunk. What I don't know is whether the capabilities of the thieves may be advanced enough such that they can re-enable keyless unlock with their equipment as if they are actually holding lock + unlock on the fob for four seconds.

If the only way to enable keyless entry is by pushing remote buttons, I don't see any way around it. I mean if they can lay hands on the remote it's already game-over.

This is a neat feature I hadn't heard about.

Auto lock is the feature that makes keyless entry worth it. Just set it to auto-lock (agree that it seems to be a function of time rather than proximity), and then set the indicator to lights only. Nothing is worse than getting out of the car in your own garage, only to be started when the horn blares just as you reach the door to the house.

I was all keyless entry (C6 Z06 and 4th gen CTS-V) for years. It doesn't take long to get completely used to driving somewhere, getting out of the car, closing the door, and walking away.

It drives me crazy when I get a dodge as a rental. The last few I've had had keyless entry but not auto-lock!

 

[sps4runner]

I just press the door lock button on the inside when I get out like every other car I've had.

 

[bloominguez]

According to the manual, you can disable and re-enable keyless entry by holding the lock and unlock buttons on the key fob for four seconds. If this actually disables the RF transmission capabilities to unlock the doors and trunk, this should defeat those capabilities in relay attack, at least insofar as a thief being able to unlock the doors and trunk. What I don't know is whether the capabilities of the thieves may be advanced enough such that they can re-enable keyless unlock with their equipment as if they are actually holding lock + unlock on the fob for four seconds.

View attachment 31137

Interestingly, manufacturers treat re-enabling differently. Here's a small sample size, Cadillac and Toyota, the only two vehicles I've personally owned with the passive "keyless unlocking." I did some experimentation.

Cadillac leave this disabled until you press and hold lock and unlock for four seconds (same procedure flips the setting back). You'll have to press unlock on the fob every time you want to get in the car. By the way, automatic locking (as you walk away) is a separate setting and is still enabled if you separately set it that way.

Toyota automatically re-enable keyless unlocking the first time you press unlock on the key fob. Basically, once you open the car with the fob, it's back to keyless unlocking. You have to disable the keyless unlocking every time. I'll typically only do that if I know I'm going to park the car for a period of time. But with Cadillac, I don't have to, that setting is remembered.