Tesla In his investigations, the user who simply goes by 'green' claims that Model S and X vehicles with firmware 2020.48 and up now have the allowance for something referred to as "service key". It's the same field in the coding used on the 3 and Y for phone keys and key cards, but the space where this code is found was previously empty for the larger pair of Tesla EVs. His digging revealed that the code is identical across all models and appears to be hardcoded. It can't be removed, either, as when he tried deleting the string of code, it simply reverted back to the original coding. The coding also suggests that Tesla service centers have a universal card key that can be used to unlock everything from the Model 3 to the Model X.