After less than 2000 miles, the OnStar module failed, which removed the capability for emergency assistance, GPS, advanced cruise control, etc. The part is on back order with no ETA, and it appears, based on my research, that this is a common problem with GM vehicles for the past several years. Not having the emergency assistance phone system available is an extreme safety issue, as there are many areas of the US that do not have adequate cell coverage to get assistance in an emergency. It seems as though GMC does not care.
NHTSA ODI 11692360