Have you already looked at the pickled data? Because it looks like the model is outputting a single label value out of 256 labels; depending on the training data (steering angle) and how it is represented in the data (signed float or integer?), each one of those 256 learned should (?) be similar - I think.
Again, I'm not an expert. Or - maybe it is outputting a number 0-255, and then taking that number and converting it (and maybe other operations) into values suitable for the servo on the car (perhaps centered around 0 - so -128 to 127 or something like that - then scaled for servo PPM width or whatever values needed)...
All guesses, of course.