E6 error codes?

I’ve tried to do my due diligence and search this forum and google for answers, but haven’t been able to find them yet. We have a few 2015 Polaris GEM E6 cars and lately have been having some issues. The cars have Sevcon Gen size 4 controllers, and Delta q chargers. I’m looking for a list of VEH fault codes. Or at least someone who might be familiar with specific codes. Right now we have a car giving code 945. And it won’t run. We have another one that is giving code 520500 but still runs. One of the batteries is really dying and needs to be replaced, but there doesn’t seem to be any leads reading individual batteries in it.

did you see this post

That post doesn’t have any information about fault codes. Our problem isn’t the fwd/reverse switch.