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:
How to Reset the Engine Oil
Life System
Reset the system whenever the
engine oil is changed so that the
system can calculate the next
engine oil change. To reset the
system:
1. Turn the ignition to ON/RUN with
the engine off.
2. ...
Adjusting the Treble, Midrange,
and Bass
1. Press the TONE button.
2. Select Treble, Midrange,
or Bass.
3. Select the value.
Press the BACK button to go
back to the Tone Settings menu. ...
Steps for Determining Correct Load Limit
1. Locate the statement “The combined weight of
occupants and cargo should never exceed
XXX kg or XXX lbs” on your vehicle’s placard.
2. Determine the combined weight of the driver
and pa ...