When you first power up the truck it should come up to user ID, then you need to hit the "I" button twice until it states Atlet code or Authorized code, then enter the code 0002468, and this will take you into the menu tree. Then hit the "6" button until "set options" is displayed then hit "Enter" button to go into it, then you can scroll down with "8" button. If you are there and "Enter" button not working then either keypad or ribbon cable bad. Hope this helps.

I need more help; tried to go the options by pressing the ENT key, could not get into the menu

E100 is stating that you have a CAN Buss error. If you just installed new controller then you need to go to options and set them up correctly. Let me know if you need more help.