See also:

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). †...

Onstar.com
The website provides access to account information, manages the OnStar subscription, and allows viewing of videos of each service. Get subscription plan pricing and sign up for OnStar Vehicle Diagnos ...

Service Vehicle Messages
SERVICE A/C (Air Conditioning) SYSTEM This message displays when the electronic sensors that control the air conditioning and heating systems are no longer working. Have the climate control system s ...