2003 Malibu...does it have alarm? How to arm/disarm?

Hey everyone. I'm in Canada, Ontario. A friends 03 Malibu was broken into...nothing taken and I was wondering something, so I can pass it along to him.

The car has the remote, 4 button. Lock, unlock, trunk, panic button.

The doors lock; they unlock; the panic button sounds and the horn/everything goes off like an alarm should.

Here's the thing, if you open the doors after you lock them(like it was broken into) nothing happens. No alarm.

Did this Malibu have it disabled; can it be fixed/programmed so the alarm sounds when the doors are open?

Any help would be appreciated...don't want him to spend money if he can do anything himself.

Thanks.