python 990 doors will no longer lock

Hello.. A couple years ago, I had a Python 990 installed in my 2006 Chevy Tahoe by Circuit City. I recently noticed that the lift gate was no longer locking when I engaged the alarm. Only after investigating did I realize that none of the doors were locking but the alarm is being set. If I open the doors, the siren will sound. I've search DEIs site as well as the Python specific site but only found 1 document about the door locks. It said to bring the vehicle to an authorized dealer for repair. I suppose I could do that but I don't feel that's the answer just yet. Can someone point me in the right direction as to what to look at? Could this be something w/ the remote itself? I've thought about trying to reprogram it but figured I'd ask for suggestions before trying that. Thanks in advance for your suggestions.Beth Anne

more details.. The doors lock correctly if I use the lock button inside the vehicle. It's definitely with the alarm.Beth Anne

ok, you have to find the alarm brain and test the door lock outputs. if they are bad you need to replacethe alarm. Send brain in with copy of your receipt to Directed Electronics. No Receipt then you gotta pay for the repair or a new one.

If outputs test good then you have a bad data bus module either it lost power or`needs reprogramming

this module connects to the purple wire behind your OBDII plug under your dash. you can trace that wire back to the location of the GM DATABUS MODULE. Check all the connections. Get the part # and let use know we can help you better

Great.. Thanks for the input topinstaller200. We'll have a look this weekend and let you know what we find.Beth Anne

Just so I'm clear. Is the GM DATABUS MODULE an OEM part or is it something that Circuit City would have added when they put in the unit?Beth Anne