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:
Emissions Inspection and Maintenance Programs
Some local governments may have programs to inspect the on-vehicle emission control
equipment. For the inspection, the emission system test equipment is connected to
the vehicle’s Data Link Conn ...
Heated Mirrors
For vehicles with heated mirrors:
(Rear Window Defogger):
Press to heat the mirrors.
See “Rear Window Defogger” under Dual Automatic Climate Control System on page 8‑4 for more informati ...
Engine Coolant Heater
The engine heater can provide easier starting and better fuel economy during engine warm-up in cold weather conditions at or below −18°C (0°F). Vehicles with an engine heater should be plugged ...