See also:

OnStar Mobile App
With an iPhone® or Android™-based mobile device, an OnStar mobile app can be downloaded. The vehicle can be remote started, if equipped, or the doors can be unlocked from anywhere there is cell ...

Maintenance when Trailer Towing
The vehicle needs service more often when pulling a trailer. See Maintenance Schedule on page 11‑3. Things that are especially important in trailer operation are automatic transmission fluid, en ...

How to Check Lubricant
2500HD with 6.0 L All Other Series and Engines To get an accurate reading, the vehicle should be on a level surface. • For all 4.3 L, 4.8 L and 5.3 L 1500 Series applications, the proper leve ...