Reactivation for Subsequent Owners
Push 
and follow the prompts to
speak to an Advisor as soon as
possible after acquiring the vehicle.
The Advisor will update vehicle records and will explain the OnStar service offers and options available.
See also:
Engine Oil Additives/Engine Oil Flushes
Do not add anything to the oil.
The recommended oils with the dexos specification and displaying the dexos
certification mark are all that is needed for good performance and engine
protection.
...
Tire Messages
SERVICE TIRE MONITOR SYSTEM
This message displays if there is a problem with the Tire Pressure Monitor
System (TPMS). See Tire Pressure Monitor Operation for more information.
TIRE LEARNING ACT ...
Service Parts Identification Label
This label, on the inside of the glove box, has the following information:
Vehicle Identification Number (VIN).
Model designation.
Paint information.
Production options and special equipment ...