Vehicle and Power Issues
OnStar services require a vehicle electrical system, wireless service, and GPS satellite technologies to be available and operating for features to function properly. These systems may not operate if the battery is discharged or disconnected.
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.
Engine ...
Speedometer
The speedometer shows the vehicle's speed in either kilometers per hour (km/h) or miles per hour (mph). ...
Making a Call
To make a call:
1. Press 5 once or twice (depending on the radio).
2. Enter the phone number.
3. Select Call to start dialing the number. ...