Security Light

The security light should come on briefly as the engine is started. If the system is working normally, the indicator light turns off. If it does not come on, have the vehicle serviced by your dealer.
If the light stays on and the engine does not start, there could be a problem with the theft-deterrent system.
This light is also used to indicate the status of the anti-theft alarm system when the ignition is turned off. The light will flash rapidly if the alarm system is arming and one or more of the monitored entry points is not closed. The light will stay on if the alarm is arming and all entry points are closed.
For information regarding this light and the vehicle's security system, see Anti-theft Alarm System on page 2‑11.
See also:
Passing Another Vehicle While Using Cruise Control
Use the accelerator pedal to increase the vehicle speed. When you take your foot off the pedal, the vehicle will slow down to the previous set cruise speed. ...
New for 2010
GM has dropped the long-running 6.0-liter V-8 engine from the Sierra lineup,
leaving the powerful 6.2-liter V-8 for heavy towing needs. The rest of the
Sierra's eight-cylinder lineup benefits from ...
Arming the System
To arm the system, do one of the following:
○ Press on the RKE transmitter.
○ Lock the vehicle using the key in the driver door.
The alarm automatically arms after about 30 seconds. Th ...





