I am posting this because I was able to fix the repeated radio reboots in the 2018 Nissan Rogue I drive, and this thread is the closest thing I've found to my issue on the web. Maybe this will help the next guy...
The issue in my Rogue had to do with the radio rebooting frequently. Sometimes it wouldnt happen until I started driving, sometimes it would happen right after I turned the car on.
My case was the same as the situation described by @teeshot. I had done an update to the NC/SC map, and after that the reboots begun. It seems that TomTom messed up the stand-alone map update file for at least the NC/SC region. I'm not sure about the other regions.
There is no way to undo that update from the car. There is no point downloading all other updates either... yeah, I tried that too.
The way to fix this is as follows:
- grab a 16GB usb stick or bigger (some 16GB sticks won't work because they are actually 14.2GB and the update you will need is 14.7GB, so I used a 32GB stick)
- plug the usb stick into your Rogue's USB port (the same one used for carplay / android auto), and go to information -> system updates -> map updates -> copy date to usb (or something like that, I'm doing this from memory)
- remove the stick from the Rogue when told to do so and go to your computer
- download Nissan's map update tool for PC or Mac, install it, and launch it
- plug the usb stick into your computer
- navigate to the map update tab that will contain the single consolidated download package (as opposed to the per-region downloads), and download that - this will take you a while
- once that is done, eject the stick from your computer and go to your car
- start the car, do not drive (as that will trigger the reboot issue), and make sure that the radio will not start the reboot cycle while parked. if it does, try to hold down the power button until it shuts down, and restart the car, making sure that the radio won't auto-reboot.
- once the radio is stable while parked, plug in the usb stick and go to the same place in the settings: info -> system updates -> map updates -> install map data from usb stick. this will take a while as well. do not turn your car off nor drive it while this is going on.
- once the process is done, restart your car for good measure, and hopefully your problem will be fixed like mine was.
While inconvenient, this beats arguing with Nissan and having your HU replaced, as there is most likely nothing wrong with it.
Ah, before I forget: to those that said that the map is unrelated to the rest of the unit: this is incorrect. Everything is connected inside the car, and a corrupt map data file can indeed cause the whole system to panic and to end up rebooting in an attempt to fix itself.
I hope this helps the next guy.