Navigation
OnStar navigation requires the Directions and Connections service plan.
Push 
to receive directions or have
them sent to the vehicle navigation screen. Destinations can also be forwarded to
the vehicle from Google Maps™ or MapQuest.com. The OnStar mapping database is continuously
updated. Visit www.onstar.com for coverage maps.
See also:
Overview
The GMC Sierra All Terrain HD concept is an exploration of heavy-duty truck
capability combined with greater off-road versatility. It is highlighted by a
bold exterior design, enhanced all-terrain ...
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).
...
Engine Oil
For diesel engine vehicles, see “Engine Oil” in the Duramax Diesel Supplement.
To ensure proper engine performance and long life, careful attention must be paid to engine oil.
Following these si ...