Key positions....see explanation belowl


As I posted over a few days, I have had trouble with my Fob locking the door. Solution from another user was jump up and down....I chose to shake it. Same exact results with both Fobs. That always worked but the problem kept getting worse to the point that it didn't work much of the time. If you have a similar issue here is some information on what I did that seems to work.
1. I changed the batteries and that didn't resolve the issue but may have made a slight difference.Hard to tell because of the erratic nature of the problem. To get the cover off you need to press the key release and remove the rear key. Press it again and slide the back cover down. I have a good grip and couldn't get it off so took a piece of tape-sticky side down and left enough to roll up and press. This worked.
2. I used an alcohol glass cleaner packet to clean the contacts. I carved a narrow piece from a popsickle stick and carefully rubbed the contact points inside the Fob.
3. Reassembled and my wifes Fob worked well for about 5-6 times. I did my Fob and observed a faint discoloration on the material so apparently there was contamination. Maybe Kentucky Fried for lunch just before working on the assembly. The battery had a faint fingerprint.
When it came time for mine, the vehicle couldn't detect the key so I put it in the slot in the center console and had to push start 3 times before it worked. Earlier I had tested the Fob without a battery and was able to start it with the Fob in the slot but had to try several times. Thought maybe it would start without anything if I pushed enough times but it wouldn't so it must have some way to detect the fob even with a dead battery.
For the next day lots of weird things with my Fob. First time out it failed to lock but has worked well all day since. Then I noticed that after exit when the lights and MBUX clear it would lock the car. Tonight as I was going to see if a setting had changed it stopped locking.. I think I have a resident.ghost.
I did discover one interesting feature of the Fob. You can insert the key and have the top exposed to add a ring and other keys. Or if you press the release again and press down it will completely recess. Pressing the release again it will pop out and again to release the key. Pic's above.

 

Question regarding convenience opening/closing:

Page 82 of the Owner's Manual says to press and hold down the Unlock button on the key fob to unlock the car and also open the windows and sunroof.
Pressing and holding down the Lock button reverses the process,

I've attempted this but the car only unlocks/locks; no windows open/close. I did not read anywhere thta this was a feature that had to be activated. Any suggestions?

 

I have to press the unlock/lock button twice and hold it down on the second press and it works for me.

 

What have you been doing with your fobs?! Those things are beat up!

 

I’ll give that a try tomorrow. Thanks.

 

It usually is alone in my pocket. Sometimes it’s rubbing against the Audi Fob. The scratches are barely visible with the naked eye.

 

Not sure if you have pano or now, but usually the shade for the pano opens first, then all the windows open. That’s how it works in the E and S classes.

 

Mine works with one long (3 s or so) push.

 

I’ll double check mine then. Maybe I’m not close enough to the vehicle the first time I press it the first time since I’m usually walking up to the car when I do it.

 

Lock to open is still not working but has improved since I changed batteries and cleaned the contacts. It’s now working more than half the time the last few days. It occurred to me that removing the batteries could reset the system since I had to put the Fob in the slot in the center storage compartment for the car to recognize the Fob. Still works 100% of the time after I shake the Fob.
I have an appointment Wednesday so will see if they can figure it out.

 

Here’s what I found.
There is an internal TSB on the issue not released to dealer.
The Fob has an internal switch that turns off power after they aren’t in use for some time. How long not known by dealer but days.
Both of my Fobs are defective....they are turning off prematurely.
New Fobs were ordered.

 

Update-Replaced on July 31st and worked 2 days. Today mine failed again. I shook it and it worked.

 

Dang

 

Took the 2nd Fob out today and it failed to lock both times I used it.

 

Must be a problem on the receiving end?

 

Thats been my thinking from the beginning but it’s hard to reason the “shake it to work fact”. The way it started-new with no issue for several weeks followed by increasing rate of failure. What are the odds of my getting 4 bad ones when so few others report a problem? I have so many other strange things happening so it looks to be a software conflict of some kind.
I remember reading about how many (4 or 5) independent contractors provided different MBUX features like AI, Maps, etc. There’s a good chance that they don’t always play nice together.

 

Well almost a week with the new Fobs and both are a POS. The new one I tried first works less than 50% of the time and the other one is the worst of all 4. It fails often and sometimes shaking it in my pocket doesn’t help. For the other 3, I could grab the top of my pocket and give it a gentle shake....then they worked. This second new Fob sometimes requires that I remove it from my pocket and give it a big shake. Adding all this up I just have to assume it’s the Fobs but maybe the vehicle receivers are weak also. Zero failures with unlocking no matter how long I let the Fob sleep before trying
I can’t believe there are so few others with this problem and I have 4 bad Fobs. Should I try another 2 Fobs or wait a while to see what Mercedes figures out, that is the question!
Edit-I forgot but I had my first unlocking issue today. Failed 3 times but worked the 4th time without shaking. I had to leave my hand inside the handle for a couple of seconds and then it worked. My wife thinks that “Christine” from the Steven King novel had an Albino White sibling!

 

Crazy. I wonder if your particular fobs are on some “fringe” frequency or something. Or being interfered with by some local interference. I assume this occurs at various locations. I had a weird experience a couple years ago. Stopped by local weather bureau at our airport on my Harley. When I went to crank to leave it was completely dead. Some sort of radio interference shut down my fobs. Just grasping at straws.

 

Ron, I had to "wiggle2 the fob in my pocket occasionally. Since I have had 3 software updates because easy entry/exit wasn't working haven't had to do this.

 

Thanks....From the number of transient glitches there almost have to be software conflicts in the System. It’s such a neat car that I will patiently wait for a fix.

 

Thanks Ron....it would have to be something with my phone that has NFC (off) since it happens anywhere. Even happened at a Golf Course miles from town.

 

I have to jiggle both of my fobs sometimes. One fob seems to be a little better than the other but who really knows.

 

Mine did it again today, but I thought I might not have closed the door all the way - although it looked closed, no gap. Shook my fob all over the place and made no difference. Opened and closed the door and it worked. Made me think there's some super sensitive door closed sensor or something.

 

Crazy issue. I have Soft Close doors so doubt that’s my issue. Mercedes me didn’t show any open door yesterday when mine didn’t work again.

 

Who knows - that might exactly be the issue!! : )