Does a replacement (used) factory amp need to be programmed to the car?

Beyond that, if you have extra time to read, here's the situation...
The sound stopped coming out of my radio. It was intermittent for a while, then permanent. All the controls and displays work. I swapped in a used amp and still same problem. I wired (very temp) and external amp to the radio low-level wires coming to the amp and got music. I checked the amp's 12V & Gnd - good. The pink "radio on" wire always has 12V. (I expected only when radio on) I don't know what the light-green "remote radio control signal" wire is for. I see changing voltage on it.
Is my replacement amp bad? Any other suggestions? Thanks!
2009 Cobalt SS LNF

 

Well, i got the answer to my primary question, but I would still appreciate any help you can give for figuring out my problem.

Holy cow! After months of no sound from the radio, it started working just before arriving home today. I swapped in the used amp and it also worked - no programming needed.

I have tried tapping on the amp as well as pushing and pulling on the connectors (not unplugging) both when I have and have not sound. Those tests yielded no changes. So I'm stumped on what to try next. I really don't want to do an aftermarket amp just for this.

 

The amp doesn't need programming, only the radio itself. Like any electronic, you should test both the ground and the power with a multimeter and confirm there is a signal (or shorts; should be 12V and 0). Since you got a used one, I was also clean out the terminals with electrical spray cleaner (or maf cleaner, both leave no residue).

 

Thank you, ProfDNS.
As I feared, it quit working again. I double checked the 12V and Ground going to the amp and they look good. Used spray contact cleaner on the amp and radio pins and also on all connectors. I've tried tugging and pushing on wires while connected. No luck.
What is the function of the amp's wire "remote radio control signal?" That's the only one I don't know what it is for.

 

As to the "remote radio control signal" question, post #37 of this thread says that it tells the amp to turn off when things like blinkers and radio are done. I suspect that may be my problem, the radio incorrectly telling the amp to turn off. I will try disconnecting this wire.
https://www.chevyhhr.net/forums/audi...e-15248/page2/

 

I cut the light green wire. It didn't help. :-(

 

In case anyone in the future cares, I finally found the problem. I would think I would find this at the beginning, but somehow didn't.
The problem was that the 20A amplifier fuse was not making a good connection in its socket.