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:
Emissions Inspection and Maintenance
Programs
Some state/provincial and local governments have or
might begin programs to inspect the emission control
equipment on the vehicle. Failure to pass this inspection
could prevent getting a vehicle ...
StabiliTrak® OFF Light
This light comes on when the StabiliTraK system is turned off.
If the Traction Control System (TCS) is off, wheel spin is not limited.
If StabiliTrak is off, the system does not assist in controll ...
When to Add Engine Oil
If the oil is below the L mark for the L6 engine or
the cross-hatched area at the tip of the dipstick
for the V8 engine, you will need to add at least one
quart/liter of oil. But you must use the ...