2010 Chevrolet Cobalt Owner's Manual - Page 123

If you press the lock button on the transmitter a second time while all the doors are closed, the system will arm immediately. The system will still arm in 60 seconds if a door is open. When the open door is closed, it will also become armed. The security light, located on the instrument panel cluster, will turn on to indicate that arming has been initiated. Once the system is armed, the security light will flash once every three seconds. If the security light is flashing twice per second, this means that a door is open. If you do not want to arm the system, you may lock the car with the manual lock knobs, or the power door lock switch, if equipped, on the doors. If the system is armed and the trunk is opened using the trunk release button on the transmitter, the system will temporarily disarm itself and re-arm when the trunk has been closed. This allows you to exit the vehicle, lock the doors using the transmitter, and open the trunk using the transmitter without having to disarm and re-arm the system. Once the system is disarmed, the security light will stop flashing. How the System Alarm is Activated If the system is armed, it can be activated by either: . Disarming the System You can disarm the system by doing any one of the following: . Opening the driver's door or trunk. This will cause a ten second pre-alarm chirp followed by a thirty second full alarm of horn and lights. Opening any other door. This will immediately cause a full alarm of horn and lights for thirty seconds. . Press the remote keyless entry transmitter unlock button. Turn the ignition on. When an alarm event has finished, the system will re-arm itself automatically. . 3-17