Unable to Connect to OnStar Message
If there is limited cellular coverage or the cellular network has reached maximum capacity, this message may come on. Push Q to try the call again or try again after driving a few miles into another cellular area. Vehicle and Power Issues OnStar services require a vehicle electrical system, wireless service, and GPS satellite technologies to be available and operating for features to function properly. These systems may not operate if the battery is discharged or disconnected.
See also:
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 ...
Cargo Tie-Downs
Four cargo tie-downs are located in the rear compartment of the vehicle.
The tie-downs can be used to secure small loads. ...
Towing the Vehicle
Notice: To avoid damage, the disabled vehicle should be towed with all four wheels off the ground. Care must be taken with vehicles that have low ground clearance and/or special equipment. Always flat ...