I have a GEN2 that the software is corrupted on. (the dwell times in the car features (M1313) won't respond to any changes and I get different dwell times on even floor vs odd floors.

I can purchase the OCSS chips from Otis, and I would like to change it without paying Otis $770/hr to do it for us.

When changing the Z chips for a software upgrade, I remember changing the Checksum when I worked for Otis, but I can't remember exactly how to do this.

Are there any other problems I could encounter if we choose to do it ourselves?