Unbricking 8.4AN after latest update
Brand new member here. I bricked my 8.4AN when I tried to install the most recent uconnect update. I spent some time looking everywhere for an answer to get it back to "normal". The update failed on the embedded air card (probably why my navigation was/still is messed up). I tried to go back to an earlier firmware, but to no avail - I still had the screen telling me to insert update usb.
I kind of got lucky, but here is what I did to unbrick it. Just wanted to share to help anyone else out who might have gotten stuck in this pit of misery. Insert the USB stick in ACC mode just like you were going to do the update. Let it fire up and get to step 1 where it is validating the ISO file. Let it go to about 8%, then turn the engine to off and immediately open the door to kill everything. Pull the USB stick out, close the door, and fire it up - Jeep logo on screen and everything loads back up. Even have the Siri update on there now.
Hope this helps anyone else out that has had the same problem I did!