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/ ...
Leaving the Vehicle With
the Engine Running
(Automatic Transmission)
WARNING!
It can be dangerous to leave the
vehicle with the engine running.
The vehicle could move suddenly
if the shift lever is not fully in
P (Park) with the parking brake
firmly set. And, ...
Trailer Sway Control (TSC)
Non-hybrid vehicles with StabiliTrak have a Trailer Sway Control (TSC) feature.
If the vehicle is towing a trailer and the system detects that the trailer is swaying,
the vehicle brakes are applie ...