From the first post, it seems as though a2 (*2) is already programmed as a163.
From Business Feature and Specs:
1. Press the Speaker key.
2. Dial the Voice/Tone Programming access code and receive feature dial tone. The LCD will show the current
mode of the Multiline Terminal.
3. Dial any single digit (0-9). Voice mode is switched to Tone mode (or vice versa) and Service Set tone is
received.
I have always used 1 after the access code and trained end users with the very same procedure. If star works, great! It's a new one on me. It basically boils down to rbender going to the phone that is answering in voice mode and toggling it back to tone mode. I think you will agree with me that this feature cannot be toggled on or off in CAT / MOC mode, only the access code can be altered, added or deleted in CM 200