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:
Engine Coolant Temperature Gage
This gage shows the engine coolant temperature.
If the gage pointer moves into the red area,
the engine coolant has overheated.
If you have been operating your vehicle under
normal driving c ...
Rear Window Sunshade
On vehicles with a rear window
sunshade, the switch is on the
console to the right of the shift lever.
The sunshade only operates when
the ignition is in ON/RUN or ACC/ACCESSORY.
To open the s ...
Checking Coolant
The vehicle must be on a level surface when checking
the coolant level.
The coolant level should be at or above the FULL
COLD mark when the engine is cold. The coolant level
should be above the ...