This vehicle has an anti-theft alarm system.

The indicator light, on the instrument panel near the windshield, indicates the status of the system: Off : Alarm system is disarmed.
On Solid : Vehicle is secured during the delay to arm the system.
Fast Flash : Vehicle is unsecured.
A door, the hood, or the liftgate is open.
Slow Flash : Alarm system is armed.
Vehicle Security
Arming the Alarm System#PIT5236: Diagnostic Tip: OnStar Module Does Not Support All B101D Symptom Codes - (Oct 3, 2013)
Subject:Diagnostic Tip: OnStar Module Does Not Support All B101D Symptom CodesModels: 2011 - 2014 All GM Passenger Car and Light Duty Trucks with RPO UE1(Except 2011-2013 Chevrolet Corvette, 2011-2012 Chevrolet Colorado, 2011-2012 GMCCanyon)The following diagnosis might be helpful if the vehicle ex ...