John Deere Payload File

The John Deere Payload File is used in configuration and diagnostics for John Deere tractors, and is controversially proprietary and encrypted, accessible only to authorized personnel. This has come under fire by people who feel that owning one of the tractors should give them the right to maintain, reconfigure, and diagnose it themselves. Some unauthorized utilities have been developed to do this, running afoul of U.S. copyright law and its draconian anti-circumvention provisions. (The Ukranians have done much of this hacking, since they are out of reach of U.S. law enforcement.) Some attempts have been made at the state level to get laws passed which guarantee tractor-owners' rights in this area.

It's been found that it's possible to "hack" a John Deere tractor by simply putting an empty text file named  on it; this grants dealer-level access.

Links

 * Why American farmers are hacking their tractors with Ukranian firmware
 * Video of PLD encryptor/decryptor