Read this whole text i wrote on another post:
Hey guys,
So due to popular demand ( I suppose ) I will describe what i did in order to unbrick my headunit in my ioniq ev 2019.
A quick summary of why my HU died. Like other car nerds I installed different apps on the headunit, through the hidden service/android menu.
Days later i went to my dealer and asked them to update to the latest software. ( I didnt know back then that the latest sw blocks the hidden android menu, )
after the upgrade the headunit went into boot loop and the dealer didnt know what to do abou it.
I spend weeks searching the internet to the deepest of the deepest sites to find any ways of recover it. Untill i saw a thread on reddit on this guy who accidently or randomly tried some keyboard commands on the car.
So the method is:
Plug in a usb keyboard to the front usb port of the car. and turn on the car. Then repeatedly press ALT + PRINT SCREEN + E. This will take your head unit into forced firmware update (I think). After doing it repeatedly the unit told ME that it was doing firmware update (but no usb with update was plugged in). To another person in another forum that had the unit bricked it told him (after several presses) that there was an issue with his firmware and to rollback. Everytime you press the combination, the touch stops responding, after a couple seconds it reboots. If you press the combination BEFORE it boots you will see weird lines on the screen. It will restart itself. If you keep doing it, it will eventually tell you that its a firmware update or, in the other case, will tell you if you can rollback the FW. CTRL + ALT + DEL will reboot the unit (Tested on a Hyundai Ioniq hybrid early 2019 EU and Hyundai ioniq EV 2019. EU )
Another guy on this forum " Koln Bonner " added this info in Germany: This could be important for those who can not make the key commands i mentioned to work.
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Falls die oben stehenden Tastenkombinationen nicht funktionieren:
Von Linux kenne ich folgendes, wenn gar nichts mehr geht: ALT+Druck/SysRq halten, und dann langsam REISUB schreiben (alle 2 Sekunden ein Buchstabe).
Das führt nacheinander folgende Kommandos aus: "unraw" (Kontrolle über Tastatur übernehmen), "terminate" (Kommando an alle Programme schicken, dass sie sich beenden sollen), "kill" (alle Programme beenden), "sync" (Daten aus Cache auf Festplatte schreiben), "unmount" (alle Dateisysteme nur lesend mounten) und "reboot" (sofort neu starten).
Da das auf einem niedrigen Level im Linux Kernel implementiert ist, der auch von Android verwendet wird, gehe ich davon aus, dass das auch geht.
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Google translated:
If the above keyboard shortcuts do not work: From Linux, I know the following, if nothing works at all: ALT + PRINT, and then slowly write REISUB (every 2 seconds a letter). This executes the following commands one after the other: "unraw" (take over control of keyboard), "terminate" (send command to all programs that they should quit), "kill" (quit all programs), "sync" (data from cache write to hard disk), "unmount" (all file systems mount only read) and "reboot" (reboot immediately). Since this is implemented at a low level in the Linux kernel, which is also used by Android, I assume that this is possible.
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Anyways, hopefully you guys with the bricked headunit get it to work again. Another tip is, MAYBE i was lucky i made it work, the trick is sometime to wait.
when the scramble screen comes, i think its doing something in the background which you cant see. maybe a count down to roll back. try and leave it there for 1 min or something. then CTRL + ALT + DEL. This was few months ago for me, so i cant remember exactly. but I think the menu with " roll back Yes - NO " was barely visible in the scrambled screen.
Good luck!
