If your vehicle has power locks, it will have the delayed locking feature.
This feature will delay the actual locking of the doors for up to five seconds when the power door lock switch or remote keyless entry transmitter is used to lock the vehicle.
If any door is open when locking the vehicle, three chimes will sound signaling that the delayed locking feature is active. Five seconds after the last door is closed, all of the doors will lock and the turn signal lamps will flash. To cancel the delay and lock the doors immediately, press the lock button a second time.
This feature will not lock the doors if the key is in the ignition.
You can disable this function through the Driver Information Center (DIC). See DIC Vehicle Personalization.
Power Door Locks
Automatic Door LockChevrolet Cobalt Owners Manual. Running the Vehicle While Parked
It is better not to park with the engine running. But if you
ever have to, here are some things to know.
WARNING:
Idling a vehicle in an enclosed area with poor
ventilation is dangerous. Engine exhaust may
enter the vehicle. Engine exhaust contains
Carbon Monoxide (CO) which cannot be seen
or ...