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:
Setting the Tone
(Bass/Midrange/Treble)
BASS/MID/TREB (Bass, Midrange,
or Treble): To adjust bass,
midrange, or treble:
1. Press the TUNE/TONE knob
until the tone control tabs
display.
2. Continue pressing the TUNE/
TONE knob, o ...
Security Light
The immobilizer light should come on briefly as the engine is started.
If it does not come on, have the vehicle serviced by your dealer.
If the system is working normally, the indicator ligh ...
Automatic Transmission Shift Lock Control Function Check
WARNING
When you are doing this inspection, the vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before starting this check, be sure there is enough room ...