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:
Reactivation for Subsequent
Owners
Push and follow the prompts to
speak to an Advisor as soon as
possible after acquiring the vehicle.
The Advisor will update vehicle
records and will explain the OnStar
service offers and opt ...
Engine Heater
The engine coolant 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 ...
How to Check
Use a good quality pocket-type gauge to check tire pressure. Proper tire inflation
cannot be determined by looking at the tire. Check the tire inflation pressure when
the tires are cold meaning th ...