Does anyone have a listing for the Honda Interface Module error codes?

I got it from ebay and haven't used it in over a year. Before I plugged it in to check my CEL, I decided to run a self test on the HIM. When I did I got a C2, 129 error.

I'm hesitant to plug it into my car without knowing what is broken out of fear that it could mess with my ECU.

I suspect calling the helpline as the HDS suggests would not work out as I doubt the one I have is legit (despite it being advertised as "GENuINE HoNdA" when I bought it).

TIA