Diagnostics
OnStar Vehicle Diagnostics will perform a vehicle check every month. It will check the engine, transmission, antilock brakes, and major vehicle systems. It also checks the tire pressures, if the vehicle is equipped with the Tire Pressure Monitoring System. If a diagnostics check is needed between e-mails, push 
, and an Advisor can run a check.
See also:
Shifting Into Four-Wheel Drive High or AUTO
(Automatic Four-Wheel Drive)
Turn the knob to the Four-Wheel Drive High or AUTO position. This can be done at any speed, except when shifting from Four-Wheel Drive Low. The indicator light will flash while shifting. It will remai ...
If You Cannot See the HUD Image When the Ignition Is On
• Is anything covering the HUD lens?
• Is the HUD dimmer setting bright enough?
• Is the HUD image adjusted to the proper height?
• Are you wearing polarized sunglasses?
• Still no HUD i ...
Adding or Removing Categories
1. From the Home Page press the Config screen button or the CONFIG button on
the faceplate.
2. Select Radio Settings from the Config Menu list.
3. Select Add/Remove XM Categories.
4. From the Add ...