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:
Safety Belt Extender
If the vehicle's safety belt will fasten around you, you should use it.
But if a safety belt is not long enough, your dealer will order you an extender.
When you go in to order it, take the hea ...
Service Vehicle Messages
SERVICE AC SYSTEM
This message is displayed if there is a problem with the air conditioning system.
Take the vehicle to your dealer for service.
SERVICE POWER STEERING
This message is displayed i ...
Engine Compartment Overview
5.3 L V8 Engine Shown (4.3 L V6 Engine, 4.8 L V6 Engine, 6.0 L V8 Engine, and
6.2 L V8 Engine Similar)
A. Engine Air Cleaner/Filter on page 10‑17.
B. Coolant Surge Tank and Pressure Cap. S ...