Well you probably have read the article on hacking coke machines...
I assume this can work with any Pepsi vending machine that can be programmed to say the certain things in the small screen. Getting into the debug menu is as simple as pressing buttons. Some random person hanging around with friends can accidently enter in the code and not know it. This picture shows you, in order, what buttons to press from 1-4. The manufacturers could have made it a complex series of button presses or at least a button inside the Pepsi machine. I try to remember the code by Left, Left, Right, Right but there are many different ways to remember it.
The picture has each button numbered and below is a key to match the numbers with the function the button has. I don't know what all of the buttons do so I will tell you what the ones i know do. Those buttons are really the only ones you need to know but you can find out the other ones when you try this article out.
1,2 - Cycle right
3 - Enter
4 - Debug Quick Exit
There are two options in the Debug menu.
Diagnostics - This shows diagnostic details of the machine.
Sales Data - Shows you what each product on the buttons made and how much money there is total in the machine. To see what the separate products have made just use the cycle right button