Recommended Fuel
Use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, an audible knocking noise, commonly referred to as spark knock, might be heard when driving.
If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. If heavy knocking is heard when using gasoline rated at 87 octane or higher, the engine needs service.
See also:
Add-on Electrical Equipment
The OnStar system is integrated into the electrical architecture of the vehicle.
Do not add any electrical equipment. See Add-On Electrical Equipment on page 9‑64.
Added electrical equipment ...
Shifting In or Out of Neutral
1. With the vehicle running and the engine at an idle, set the parking brake.
2. Place the transmission into N (Neutral).
Shift the transfer case in one continuous motion into or out of the N (Neutr ...
If No Steam is Coming from the Engine Compartment
The ENGINE OVERHEATED STOP ENGINE or the ENGINE OVERHEATED IDLE ENGINE message, along with a low coolant condition, can indicate a serious problem.
If there is an engine overheat warning, but no stea ...