See also:

Accessories and Modifications
When you add non-GM accessories to your vehicle they can affect your vehicle’s performance and safety, including such things as, airbags, braking, stability, ride and handling, emissions systems, ...

Adding Coolant
If you need more coolant, add the proper DEX-COOL® coolant mixture at the coolant recovery tank. CAUTION: Turning the radiator pressure cap when the engine and radiator are hot can allow stea ...

Transferring Service
Push to request account transfer eligibility information. The Advisor can assist in canceling or removing account information. If OnStar receives information that vehicle ownership has chan ...