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:
Remote Start Heated Seats
When it is cold outside, the heated seats may turn on automatically during a remote vehicle start. The heated seats will be canceled when the ignition is turned on. Press the desired button to use the ...
Clock
To adjust the time and date:
1. Turn the ignition key to ACC/ACCESSORY or ON/RUN, then press to turn the radio on.
2. Press to display HR, MIN, MM, DD, YYYY (hour, minute, month, day, and year).
...
Compass Calibration
The compass can be manually calibrated. Only calibrate the compass in a magnetically clean and safe location, such as an open parking lot, where driving the vehicle in circles is not a danger.
It is ...