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:
Vehicle Positioning
At times, the position of the vehicle on the map may be inaccurate due to one
or more of the following reasons:
Road system has changed.
Vehicle is driving on slippery road surfaces such as in ...
Speedometer
The speedometer shows the
vehicle's speed in either kilometers
per hour (km/h) or miles per
hour (mph). ...
AVG (Average) Speed
Displays the average speed of the
vehicle in either kilometers per
hour (km/h) or miles per hour (mph).
This calculation is based on the
various vehicle speeds recorded
since the last reset o ...