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 
to try the call again or try again after driving a few miles into another cellular area.
See also:
Audio/Video (A/V) Jacks
A. Yellow: Video Input
B. White: Left Audio Input
C. Red: Right Audio Input
The A/V jacks are color coded to match typical home entertainment system equipment.
The A/V jacks, located on the rear ...
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 ...
Potential Issues
Some OnStar services are disabled after five days. OnStar cannot perform Remote Door Unlock or Stolen Vehicle Assistance after the vehicle has been off continuously for five days. After five days, OnS ...