A few months ago I purchased a very expensive car that began to throw a very annoying error into my face since the first month of ownership: "Uconnect Box requires service. Please visit an authorized dealer."
As a naive fool I visited my stealership to claim my warranty and got some insulting experience where a manager performed a small shitshow:
Long story short, there's a way to troubleshoot this error on any driveway.
Firstly, let's start with the basics. The error "Uconnect Box requires service" means nothing, it actually hides a real reason and displays a generic error for ANY problem that happens inside your telematics box. A telematics box (or TBM2) is a device that is installed above your glove box and sends/receives data to Chrysler-affiliated servers through the LTE antenna without your control over it. It also works as an adapter for the GPS cable that comes to your radio unit from the roof. So whenever a problem happens with your TMB2 (e.g. a signal with a cell tower is lost), you'll see a "Uconnect Box requires service" error message.
Secondly, you need some tools to debug your car. You can use something like AlfaOBD, DiagFCA or JScan. Their price (+ a scanner device by their recommendation) should cost no more than 100 bucks. However, I'm not affiliated with these products, so I can't guarantee their price policy in the future. I used DiagFCA + Vgate vLinker FS for screenshots below to explain how I diagnosed the problem with my TBM2 module.
I connected my cable to the laptop, installed the diagnostics software, connected the scanner cable to the OBD port under the steering wheel column. Then I opened the "Diagnostic" tab and scrolled the list down to the TBM2 module (aka telematics box). You can see on the screenshot below there are 3 columns with names "Active", "Pending" and "Stored" and any non-zero values in these columns indicate issues that present right now or happened in the past:
Then I clicked on TMB2 module and went to the DTCs tab to see actual error codes. In my case that was B1560-13 (Cellular Antenna 1 - Circuit Open), but other owners may have slightly different codes:
After that I found a document with a name S2108000085. It's a TSB that explains where the TBM module is located, how it looks, how to test connectors and where wires are put in your car. So I grabbed my trim removal set, ratchet wrench socket set and went to my car. I gently removed the weatherstrip and a bunch of panels and eventually dropped the frame of my glove box. You can see that the telematics box is sitting on the top of it:
I inspected cable connectors on the back and was initially sure that my problem is the connector #3 if we count from left to right. But after poking around, I confirmed it works OK, just looks bad. My problem was the cable #4: I removed connectors one by one when the engine was off, then I started the car and scanned errors to see if I get new errors. When I removed the connector #4, I didn't get any new errors but B1560-13, so I understood that this cable is my problem.
Then I decided to find the opposite part of this cable. It didn't look like it goes to the radio unit, so the only place where it can go is probably the fin on the roof. I dropped a few panels and found this blue connector:
I wiggled it a little bit and my next error scan came clean, so I understood that my problem is a loose connection between two wires in this blue adapter/splitter. I used a zip tie to stop movement of both halves and so far it works for 3 weeks since then, the error never came back.
I hope this information will save someone's time because I see a huge amount of people on forums like this that are waiting for mysterious Uconnect updates that can't fix hardware issues like the one above.

As a naive fool I visited my stealership to claim my warranty and got some insulting experience where a manager performed a small shitshow:
- Without looking at the car said that I probably modded something, so they won't cover anything.
- Short time after he came again and said they suspect tricky hackers were trying to steal my car with very serious tools.
- Claimed they found a problem and fixed it, but the error came back on my next trip.
Long story short, there's a way to troubleshoot this error on any driveway.
Firstly, let's start with the basics. The error "Uconnect Box requires service" means nothing, it actually hides a real reason and displays a generic error for ANY problem that happens inside your telematics box. A telematics box (or TBM2) is a device that is installed above your glove box and sends/receives data to Chrysler-affiliated servers through the LTE antenna without your control over it. It also works as an adapter for the GPS cable that comes to your radio unit from the roof. So whenever a problem happens with your TMB2 (e.g. a signal with a cell tower is lost), you'll see a "Uconnect Box requires service" error message.
Secondly, you need some tools to debug your car. You can use something like AlfaOBD, DiagFCA or JScan. Their price (+ a scanner device by their recommendation) should cost no more than 100 bucks. However, I'm not affiliated with these products, so I can't guarantee their price policy in the future. I used DiagFCA + Vgate vLinker FS for screenshots below to explain how I diagnosed the problem with my TBM2 module.
I connected my cable to the laptop, installed the diagnostics software, connected the scanner cable to the OBD port under the steering wheel column. Then I opened the "Diagnostic" tab and scrolled the list down to the TBM2 module (aka telematics box). You can see on the screenshot below there are 3 columns with names "Active", "Pending" and "Stored" and any non-zero values in these columns indicate issues that present right now or happened in the past:

Then I clicked on TMB2 module and went to the DTCs tab to see actual error codes. In my case that was B1560-13 (Cellular Antenna 1 - Circuit Open), but other owners may have slightly different codes:

After that I found a document with a name S2108000085. It's a TSB that explains where the TBM module is located, how it looks, how to test connectors and where wires are put in your car. So I grabbed my trim removal set, ratchet wrench socket set and went to my car. I gently removed the weatherstrip and a bunch of panels and eventually dropped the frame of my glove box. You can see that the telematics box is sitting on the top of it:

I inspected cable connectors on the back and was initially sure that my problem is the connector #3 if we count from left to right. But after poking around, I confirmed it works OK, just looks bad. My problem was the cable #4: I removed connectors one by one when the engine was off, then I started the car and scanned errors to see if I get new errors. When I removed the connector #4, I didn't get any new errors but B1560-13, so I understood that this cable is my problem.



Then I decided to find the opposite part of this cable. It didn't look like it goes to the radio unit, so the only place where it can go is probably the fin on the roof. I dropped a few panels and found this blue connector:

I wiggled it a little bit and my next error scan came clean, so I understood that my problem is a loose connection between two wires in this blue adapter/splitter. I used a zip tie to stop movement of both halves and so far it works for 3 weeks since then, the error never came back.
I hope this information will save someone's time because I see a huge amount of people on forums like this that are waiting for mysterious Uconnect updates that can't fix hardware issues like the one above.