See also:

Specification
Use and ask for licensed engine oils with the dexos1™ approved certification mark. Engine oils meeting the requirements for the vehicle should have the dexos1 approved certification mark. T ...

Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn the ignition to LOCK/OFF in each shift lever position. The ignition should turn to LOCK/OFF only when the shift lever is in P (Park). ...

Potential Issues
Some OnStar services are disabled after five days. OnStar cannot perform Remote Door Unlock or Stolen Vehicle Assistance after the vehicle has been off continuously for five days. After five ...