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:
Ignition Positions
The ignition switch has four different positions.
To shift out of P (Park), the ignition must be in ON/RUN or ACC/ ACCESSORY and
the regular brake pedal must be applied.
A (STOPPING THE ENGINE/ ...
Driving on Grades
Reduce speed and shift to a lower gear before starting down a long or steep
downgrade. If the transmission is not shifted down, the brakes might have to be
used so much that they would get hot and n ...
Architecture and suspension
The story starts with the XLR's backbone, upon which the car's dynamic
capabilities depend. Based on GM's new performance car architecture, this unique
and patented structure comprises steel hydro ...