This guide provides insights into accessing the debug menu of a Coca-Cola vending machine. While obtaining free drinks is unethical and illegal, you can still explore intriguing information within the menu.
Steps

Ensure the Coke machine is compatible with this method. Opt for machines with LED displays and scrolling text for debug menu access. Note that some machines may have debug menu access disabled.

Identify the Coke machine's input mechanism. Common methods include keypad entry, rectangular buttons, large buttons, or dual horizontal rows of options.

Know which buttons correspond to numbers. Understand how the product selection buttons translate to numbers based on the machine's design.

Enter the access code. Typically, the code to access the debug menu is '4 3 2 1'. Follow the sequence by pressing buttons in that order.

Look for confirmation. After entering the code, expect a change in the LED display. No response might indicate lack of debug menu support or an 'EROR' message suggesting access to the 'Error' section.

Navigate through options. Utilize the '2' button to scroll up or '3' to scroll down. Options include 'SALE' for lifetime sales, 'VER' or 'CASH' for version number or current cash (mainly on older machines), 'EROR' for error logs, and 'RTN' to exit the debug menu.

Select an option. Press '4' to view detailed information about the currently highlighted option. For instance, selecting 'SALE' reveals the Coke machine's lifetime sales.

Go back to the debug menu. Use the '1' button to exit the current menu and return to the debug menu you were previously navigating.

Check the machine's temperature. Some machines allow you to view the internal temperature by pressing the '5' button, although this feature may not be available on all machines.

Close the menu. Typically, pressing the '6' button or the coin return button will exit the menu. Alternatively, leaving the machine idle for a few minutes will also close the debug menu. On newer machines, you may need to select the 'RTN' option and press the '4' button.
Tips
Additional Information: This guide is applicable only to Coke machines, which may offer various products such as Barq's Root Beer, Sprite, Dasani, Evian, Fanta, Fresca, Fruitopia, Full Throttle, Powerade, Hi-C, Minute Maid, Nestea, Odwalla, Mr. Pibb, Planet Java, Seagram's Ginger Ale, Simply Orange, Sparkletts, or Tab alongside Coke and Diet Coke.
Warnings
Important Reminders: Attempting to manipulate vending machines for financial gain is illegal. Additionally, some establishments modify the debug menu code to prevent unauthorized access, especially in places like schools and libraries.