Horn
Press 
on the steering wheel pad
to sound the horn.
See also:
How to Check Power Steering
Fluid
Check the level after the vehicle has
been driven for at least 20 minutes
so the fluid is warm.
To check the power steering fluid:
1. Turn the ignition to LOCK/OFF
and let the engine compartme ...
Engine Oil Life System
The engine oil life system calculates
engine oil life based on vehicle use
and displays the CHANGE ENGINE
OIL SOON message when it is time
to change the engine oil and filter.
The oil life sy ...
Automatic Dimming Rearview Mirror
The vehicle may have an automatic dimming inside
rearview mirror with OnStar® and/or a compass
display. Automatic dimming reduces the glare from
the headlamps of the vehicle behind you. The dim ...