Can’t Program New Remote for Automate AM9, 2006 Chevrolet Silverado

I purchased an 06 Silverado it has an AM9 with one LCD remote that has something loose inside so it keeps playing jingle bells throughout the day. I purchased a new remote but can't get the system into program mode. When I press the valet switch as directed it doesn't chirp. I thought the valet switch might be bad and put in a new one but that didn't help. If I can't get this unit to work is there a unit I can get that I just unhook the harnesses from the old unit and put into the new unit? Thanks

I can't find an Install Guide for the AM9 system to be sure but are you turning the ignition key to ON first?Soldering is fun!

Yes, I turn the key on and press release, press and hold but do not get the confirmation chirp. I read if it was programed with a bit writer that it can only be reprogrammed with the bit writer, that may have been the case

That might be the case. Check in the AM9 program tables for settings that LOCKS making changes to program changes and remote pairing. That's the way it's done on some Viper systems.Soldering is fun!