MattC300Coupe

I think I've found a potentially dangerous flaw with the Mercedes.me remote locking function.

I was sitting in my car trying the remote locking function using the apple app. I locked the doors using the app. There was a few seconds delay before the car engaged the locking. I went to open the doors to get out like I normally would by pulling the handle - I could hear the door unlocking and the lock pin went up but the door wouldn't open!! Car did not respond! I pressed the unlock button - nothing! I pressed the start button - nothing with brake pressed and without! I had to use the app to unlock the car to get out!

I tried the same from the outside using the app to lock. The doors opened like normal when I touch the inside of the door handle.

I've not tried what happens if I get someone to touch the door handle to lock from outside while I'm sitting in the car...

Anyone else tried the remote locking via the app?!

Mike5215

I guess Mercedes didn't anticipate someone trying to lock themselves inside their car using the cell phone app. Under what circumstances would you normally do that?

lbowroom

Normal circumstances and intended use don't really matter, the logic has to be idiot proof.

lbowroom

I'll go give that I try, rolling my windows down first.

z28lt1

Yes, absolutely must be idiot proof so someone doesn't get trapped and have serious problems.

That said, isn't the interior handle mechanical? I know some cars have electronic releases (and a manual emergency over-ride), but if the handle is mechanical, I'm not sure how it matters how the door was locked...

lbowroom

So I did exactly what you described.... locked the car with the app and pulled the handle from inside... the pin popped up and the door opened normally as it always does.

lbowroom

Hmm, wait a second.. you have a 2017 C300 coupe?

Mike5215

I agree. It's not idiot proof.

MattC300Coupe

I have March 2016 build coupe. (I'm based in UK).

When I pull the handle, I can hear the door unlocking and the pin comes up. But the door does not budge! It's seems that there must be some kind of deadlock mechanism. I'll have to try this again tomorrow.

I also didn't try pressing the unlock button on the remote - shock, horror, old school push button remote!! ;-)

lbowroom

My experiment indicates that it is.... ;-) unless the coupe has different locking mechanism than the sedan

z28lt1

Did you try pulling the handle twice? That's the standard for the locked doors on the sedan at least. First pull unlocks, second pull opens.

MattC300Coupe

I agree that I would not normally do this... But what if you left your car unlocked on your drive. And your kid happens to be messing around and gets in your car. And then you get the notification on your mercedes.me app that your doors are unlocked. So you use the app to lock your car doors.

It's a bit unlikely I know! But it could happen.

lbowroom

So if you put someone in the car and then lock the car with the remote from outside that should net the same result, no?

MattC300Coupe

I think I did try pulling the handle more than once - I'll check again tomorrow to make sure.

lbowroom

That's the standard for BMW, not Mercedes. My door opens first pull.

MattC300Coupe

You mean using the key fob or the app?

I'm going to try sitting in the car and locking using the key fob tomorrow.

MattC300Coupe

That's a good point. My coupe normally opens first pull. Coming from a Porsche where it's also pull twice to open a locked door, I specifically noticed this.

Mike5215

Yeah, lots of stuff could happen. Your car could lock your family inside and then at that moment a meteor hits your house, destroying it in a massive fireball. Then the car in my scenario will have saved everyone's life. Also unlikely, but ya never know.

A famous American philosopher, Forrest Gump, once said "Life is like a box of chocolates. You never know what you're going to get". Very true.

lbowroom

The key fob, yes. Probably won't allow you to lock it with the key fob in the car but you can just roll your window down.

MattC300Coupe

I had my key in my pocket when I used the app to lock my car.

lbowroom

I get your point, Mike, but with what he describes one can use his Mercedes as a jail.

I suppose that may be the same with the BMW deadbolt system.

Engineers think these scenarios through and have sound explanations as to why they operate the way they do. My sedan does not behave as he described, I have no explanation why his coupe would be different.

MattC300Coupe

Also - note that I could not start the car or switch on the electrics even though I had my key in my pocket.

lbowroom

As did I. However, the logic may be different in that aspect. I can see the need to lock your car remotely from the app even if you left the keys in it. It shouldn't lock with a touch to the door handle. Hmm, perhaps there's no reason to not allow locking with the fob from the fob inside the car.

MattC300Coupe

Interesting... If the key is inside the car, then surely anyone can come up to the door and open it by touching the inner part of the handle?

lbowroom

Which is why I think it won't lock by touching the outside of the handle with the key inside. You keep touching it wondering why it won't lock until you realize the keys aren't in your pocket.