I am having that annoying alarm beep going on with my 2001 C2.
I shut everything including the armrest lock and everything "looks" ok.
Then I unlock the car and I get 1 beep... but nothing when I lock it, what the heck is going on?!
Something is not working with the microswitches is my guess.
Will the Durametrics software have a way to see what is making the alarm module beep or causing a fault?

 

Durametric does check the alarm system for faults.

 

I disconnected my armrest storage sensor to force my car to beep.
I prefer that to no sound at all.
But it only beeps upon locking, not unlocking.
Check that all of your connections(storage, glovebox, doors, hood, trunk) for the alarm are connected.

 

There is also a sensor between the visors and high up on the windshield area. I think those are known to fail and need repair.

 

Do you have an aftermarket radio? There is a connector to the factory radio.