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:
Using the Dial Command
1. Press and hold for two
seconds. The system
responds with “Ready” followed by a tone.
2. Say “Dial”. The system responds with “Dial using
<phone name>”. “Number please” ...
If No Steam Is Coming from the Engine Compartment
If an engine overheat warning is displayed but no steam can be seen or heard, the problem may not be too serious. Sometimes the engine can get a little too hot when the vehicle:
► Climbs a long ...
Lumbar Adjustment
Lumbar Adjustment
To adjust the lumbar support,
if available:
• Press and hold the front or rear
of the control to increase or
decrease lumbar support.
• Press and hold the top or botto ...