As I am sure most have noticed, the W221 is like a lead box when it comes to cellular reception. With Windows up and sunroof closed, I have seen my iPhone X drop to 1xRTT in some cases. I do have the convenience phone option with a phone that uses the roof antenna that never drops calls, but it would be convenient to have data connection when streaming.

Has anyone found a way to take the external antenna and amplifier and have it act as a repeater to provide good signal inside the vehicle?

This hasn't been my experience with cellular reception and I ride with the windows up all of the time.

I ride with my heavily tinted windows up all of the time, and never had anything but great cellular reception...

Jeff

That is odd - my windows are not even tinted and I have experienced this with every cellphone I have used in the vehicle. My E-class has no effect on the reception.

I have always attributed it to the IR coating on the glass from the factory and suspected all W221s had this - perhaps some do not? I can't think of anything else it could be? Any ideas?

I have a Panavise mount which means my phone is low by the card slot/dvd player on the passenger side and reception has never been a problem with any phone I've used.

Perhaps I can post a video of the drop in reception when the windows are raised and lowered and see if it makes sense to anyone. I will try to do that.

That would be cool to see. Is your tint just the factory tint?

I do not have the problem you described. Are you on GSM or CDMA?

CDMA, which could be the difference.

It is not, I have Verizon, which is CDMA, no problems.

This is really perplexing. I have to literally open my pano roof, and place the phone on the trim around the glass to get a good enough signal to use a Mobile Hotspot with the phone. It is not phone-related, as it happens to any smartphone I have used in it. I will have to do some testing...

I have always used a Motorola phone with Mercedes-Benz firmware on it and leave it in the console. It receives SMS messages and never drops calls. I was at one time on an important call from Atlanta, GA to NC without it dropping the call one time using the external antenna and amplifier built into the car.

Well, the Mobile Hotspot seems to be a different story, I have Verizon unlimited on a IPhone XR but the Mobile Hotspot is something like 600 kbps, check this with your provider.

I was just in the car a few moments ago and attempted to send a iMessage with a photo in it. It took 4 minutes to time out and said Not Delivered. A few moments later, I looked at it and it was showing 1xRTT. About a minute later, 3G, and when I lowered the two front windows, it latched on to LTE with three signal bars.

I am on iOS 13 beta 5, but I don’t see where that could matter as it does it no matter the phone.

Are you on the post data-cap Unlimited, or a grandfathered Unlimited plan?

I think I’m on post data cap Unlimited with a Hotspot at 600kbps, I picked-up this plan just because I’m always streaming in all my cars....never used the Hotspot...it is useless anyway.

Unless you have to SCN code Mercedes-Benzes away from a WiFi connection 😉

You really lost me on this one ��

Sorry - I work on these cars and program new/replacement control modules sometimes for independent workshops and need an Internet connection to Daimler HQ in Germany to perform these things. And, yes, many shops don’t have WiFi. SCN is Software Calibration Number, and is unique and is based on the vehicle VIN and the optional equipment the car came with. To replace most control modules, that module must be aware of the options that car has, and you tell it by downloading the car’s data from Daimler.

Aha, how do you get access to Daimler HQ, are you authorized to it, or are you a Daimler employee, in this case are they allow you to work for independent shops, just curious.

I have the same issue with my Verizon phone. I haven't had issues with low coverage areas until buying my 2010 S550. It's almost as if the car is a scif.
I do not, however, have as much trouble with my Sprint phone for work.
First world problems, I guess.

Or you pay a subscription maybe ��

Sprint may have a better coverage in your area which is really amazing since Verizon usually is way better.

I hacked into their network and granted myself access.

🤫

Joking, of course! I am authorized to do it. I am not a Daimler employee, but pay a lot to have a username / password and their diagnostic tools that independent workshops can not afford or have the training to operate. I spread the cost out by doing it for them and it helps them do work they would otherwise have to turn away, and stay in business. It happens to be something I enjoy as well as studied these vehicles working on my own car, and by word of mouth I had workshops asking me to diagnose vehicles and program modules for them, and it has taken off from there. It is not my full time job.

That is simply great !

I haven't noticed a dramatic drop in signal strength with the windows and sunroof all closed. That's how we normally drive... I mean, what are, we, savages? Did the S600 have an option for a heated windshield defrost, and if so would your car have it? If your windshield is well shielded and others are not,t hat could explain it.

It is ironic you mention that. There are two wires that appear to feel heating elements where the wipers rest, but they are not listed on the datacard, and I haven't seen any indication they have ever activated or if they work. I am not even sure if I can see the heating elements for them where the wipers rest.

The climate I live in, supposing they do work, should not activated them except on very rare occasions.

It wouldn't matter at all whether the heated windshield were ever used. The mere presence of either a grid (like my wife's Volvo) or a thin-film coating (such as in early Ford products) would pretty effectively turn the windshield into an RF shield as well. IF a heated windshield were offered on the S600, it's possible that either yours originally had it (possibly buried in some other option package, so not obvious on the build sheet) or at some point a previous owner had the windshield replaced with a salvage part. If you bought the car used, you never really know what may have been done "off the books".

I wonder if there may be heating elements just for the wiper areas as part of the "HEATED SCREEN WASH SYSTEM". Sucks to have your wiper blades frozen to the windshield.

Anyway, just a thought.