Car Alarms: 2002 Tahoe keyless entry alarm, valet mode, model post

Question
Hello,
My 2002 Tahoe has a factory installed keyless entry and alarm and it normally makes a single "chirp" noise when I press the lock button once on the keyless entry and a double "chirp" noise when I push unlock once.  The locks would lock and the parking lights flash telling me the doors are locked and the alarm is set.  Inside below the steering wheel there is a small red LED that used to blink every few seconds as well.
One day I accidentially hit the panic button and the alarm went off.  I did not know which button the hit to get it to stop so I hit the panic button and then the unlock button.  It stopped but now something is different.  The chirp noise is gone whenever I lock or unlock the doors and the red LED stays on all the time the doors are locked (doesn't blink).
Do you know how to make the chirp noise start again?  I really like it and think I've just hit the wrong combination of buttons and deactivated it.
Many thanks,
Greg

Answer
This sounds more like an aftermarket system than an OEM system.  Try this, open a door, hit lock, unlock, lock and see if the system does not return to normal mode.  You have the system in valet mode, as indicated by the solid LED.  If this does not work, take a look under the dash, this might require taking the dash panel(s) under the steering column down.  Under there will probably be a brain for the alarm which would have a label on it indicating the make and model.  Post back here the exact make and model if the lock/unlock/lock does not work.