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:
Add-on Electrical Equipment
The OnStar system is integrated into the electrical architecture of the vehicle. Do not add any electrical equipment. See Add-On Electrical Equipment on page 9‑112. Added electrical equipment ma ...
Blank Display
This display shows no information. ...
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 ...