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Just came back from a run and the wife got out of the passenger side to open the garage door, when she closed the door the system gave a warning that the key wasn't detected even though it was in my pocket and I had not moved, it also gave of a loud beeping sound, anyone had this issue or know what it was all about?
 

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Just came back from a run and the wife got out of the passenger side to open the garage door, when she closed the door the system gave a warning that the key wasn't detected even though it was in my pocket and I had not moved, it also gave of a loud beeping sound, anyone had this issue or know what it was all about?
According to the owner's guide, when this message appears you should put the key in the driver-side cup holder (which has a key symbol).
 

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I tried that and the message and beeping carried on. It is strange that the key fob did not leave the car and the message was triggered by the passenger door.
 

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I tried that and the message and beeping carried on. It is strange that the key fob did not leave the car and the message was triggered by the passenger door.
Mine has just done the same thing, did you find a cause?.
 

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Probably caused by the key having gone to sleep. Give it a shake and it should wake up and be recognised.
 

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Probably caused by the key having gone to sleep. Give it a shake and it should wake up and be recognised.
I gave the key a good shake and checked the battery was OK by locking and opening the doors. Car eventually found the key. The first time it happend was when my wife opened the passenger door to get out. It has happened once more when I got into the car to start it, opened door keyless as usual, left screen came on as usual and then suddenly went off and I got the 'key not detected message' on the right screen , I shuck the key around, locked unlocked the doors with the key, got another message about a Digital Key but I don't have this function set up. Eventually car found the key and I could start the car.
I wondered if was anything to do with my iPhone as when I put it on the charging mat Apple Pay opens up, it thinks there is a NFC reader near by so maybe it sends a signal that swamps that from the key. I've started to keep the phone off the mat to see if I get it again but the trouble with intermittent problems is it's difficult to know if any change you make has fixed the problem.
 

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I gave the key a good shake and checked the battery was OK by locking and opening the doors. Car eventually found the key. The first time it happend was when my wife opened the passenger door to get out. It has happened once more when I got into the car to start it, opened door keyless as usual, left screen came on as usual and then suddenly went off and I got the 'key not detected message' on the right screen , I shuck the key around, locked unlocked the doors with the key, got another message about a Digital Key but I don't have this function set up. Eventually car found the key and I could start the car.
I wondered if was anything to do with my iPhone as when I put it on the charging mat Apple Pay opens up, it thinks there is a NFC reader near by so maybe it sends a signal that swamps that from the key. I've started to keep the phone off the mat to see if I get it again but the trouble with intermittent problems is it's difficult to know if any change you make has fixed the problem.
It does say in the online manual that strong radio interference can affect the key.
 

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I've had a 2019 A200 for about a week, and have been unable to lock the car by touching the handles about three or four times.

The first time I could see 'key not detected' on the dash, but not today.

At first I thought the battery might be low in the key, so I changed to the other one, but I had the same problem this afternoon.

If I take the key out of my pocket and click the button it locks as you'd expect, but it's not ideal.

Did this problem resolve itself for you, Blueboy/Raetsel?
 

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If had the same issue today, it wouldn’t let me start the car due to the key not being detected, so I put it in the cup holder with the key symbol and it worked after that. I think it’s an issue with the key going to sleep not detecting it’s being moved about so it turns the signal for the wireless tech access off
 

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I've had a 2019 A200 for about a week, and have been unable to lock the car by touching the handles about three or four times.
1. Which part of the door handle are you touching/grabbing when trying to lock the car?

2. Which pocket do you keep the key in, and next time you want to lock the car, just give it a quick jiggle to wake it up.
 

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According to the manual I can either touch the little square or just the length of the handle to lock it.

Just tapping the outside of any doorhandle normally works just great.

I rarely have the windows open so haven't required the convenience closing feature yet...

Key is always in my right pocket, phone in the left.
 

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Yep - I use the back of my hand touched (lightly pressed) against the square indentation, 100% success rate in locking.

(a quick tap may be too brief?)

(Some people go to grab the whole handle with their hand, thus confusing the car as to whether you are trying to unlock or lock).


Key in LH trouser pocket, so is moving as I get out of the car.
 

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When this has happened neither the recess nor the handle accept my touch.

Much like the soon to be ex wife...
 

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The key might have gone to sleep then.

Or an external factor in play, eg noisy RF environment.

Keyless locking/unlocking doesn’t work well near Droitwich for example, next to the R4 LW transmitter.
 

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It's happened in Keswick, Rugby and Harpenden, so more likely not related to specific RF transmitters.

If it persists it's another one to add to the list when it's serviced in the new year.
 

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My key frequently goes to sleep and doesn't seem to wake up when I get out of the car. Hand in pocket & give it a quick shake and it works again.

Just be careful where you are when you give it a shake though 🤣
 

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It happened again today and a little jiggle in my pocket fixed it, so key going to sleep is most likely the issue.

How does one know when the battery needs replacing though?
 

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It's replaced at every Service (or every Service A or B, I can't remember which) by your authorised M-B Workshop :)


Or

One day you'll notice that no amount of jiggling of the key will wake it up, and when you resort to using your remote buttons, the red LED no longer lights up on the fob - indicating that the battery is weak or discharged.
 
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