I'd have less trouble believing that there are different passcodes for each brand, but I'm having a hard time believing that my AGCO dealer carries around one computor for Challenger, another one for Massey, another one for Gleaner, another one for AgChem, etc etc....and I have a real hard time believing that Cat ET is going to work on a Challenger tractor....but if it will, that's definitely useful information I would like to be aware of.