You might try disconnecting the negative post of the battery for a few minute.
It depends on what bozos have mucked up.

 

Not likely. Each programming session wipes out any previous fobs.

 

First, see comment #4.

Some facts will be repeated here, but I’m just trying to pull it all together.

Also, an incompetent locksmith or mechanic might fail to pair a fob, or even screw up the BCM, and then blame the car. Ask me how I know.

The fobs do not get programmed. The car is programmed to accept each fob, but will accept only a limited number, 5 or 6, I think. Some mechanics might prefer to start over even if there is room for another fob. I don’t think this is necessary, but programming only the available fobs is surely the best course.

I would set aside any aftermarket fobs, and identify any OEM fobs that show any evidence of working with the car. For those, back sure the battery clip on the green board is not loose, install new batteries, clean the contacts with a pencil eraser. Don’t put them in the old case. Test contacts with pennies. Buy brand-new cases on line. Make sure they properly fit the OEM green board; some don’t.

Any OEM fob with a good battery clip and no sign of damage to the green board can probably be place in a new case and paired to the car.

I found a couple local mechanics who used to work for Chevy or other GM dealer. They have proved to be reliable and cost-effective for me in cases like this when when a scan tool is needed. Do not assume that the dealer will be more capable than an independent shop. Maybe, maybe not.

 

I believe the issue is the Receiver Assembly, Remote Control Door Lock & Alarm.

 

The answer to #5 is to get a new case with keypad and clean the copper traces on the circuit board with alcohol and a pencil eraser. The keypad contacts are either worn out or dirty.
And see #10. I fixed mine with bits of foil under the buttons
If the RCDLR works at all it works the fob is not sending the correct signals.
If you insist, ask the dealer how much a new RCDLR and programming it is going to cost, if you survive the shock do what you want. The part was only used in 2006 and 2007.
Good luck finding a technician that has any idea how to do it, and finding the part.

 

My aftermarket DORMAN REMOTE does the same thing = I have to be right next to my SS to ALARM/LOCK IT, but I can be yards away & the UNLOCK feature works fine...

 

After Market remotes don't always fully function. Genuine GM fobs do fully function. Dorman seems to supply questionable fobs, some work fine others don't.
2008-2011 models have the RCDLR under the headliner near the rear view mirror.