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:
Following Distance
Stay at least twice as far behind the vehicle ahead
as you would when driving your vehicle without
a trailer. This can help you avoid situations
that require heavy braking and sudden turns. ...
Safety System Check
Now and then, check that the safety
belt reminder light, safety belts,
buckles, latch plates, retractors, and
anchorages are all working properly.
Look for any other loose or
damaged safety b ...
Service Only Mode
This power mode is available for service and diagnostics, and to verify the proper
operation of the malfunction indicator lamp as may be required for emission inspection
purposes. With the vehicle ...