My "check engine soon" light does NOT come on at all during initial start up,
I've had the car at the mechanics and they said they checked the bulbs and the wiring all the way to the power(battery) and they couldn't find any problems. Well there is a problem.... the light is in-operable could the fact that the ECM might have been working correctly due to the idle problem I just repaired or is there a way to reset the "check engine soon" indicator light

No, but their is a way to command the light to turn on via a high end scanner or GM Tech2 diagnostic tool.

Now, let'* verify this first. When you turn the key to ON(not start), does the light do anything?

Nothing

How did they test the CEL light all the way to the battery?

Depending on the type of system, the PCM sends a signal either straight to the cluster or to the BCM first, then the cluster.

It'* possible you may have a bad cluster, but really only a dealer can find out for sure.

No check engine light?? Wow, a lot of potential problems for your car will not exist then!

Seriously though, don't worry too much about it. Those lights are often just sensor notifications that may or may not affect your car'* performance. If your car IS performing poorly, you can still have the computer scanned for any trouble codes... although a competent mechanic should be able to troubleshoot problems either way, just like they did for decades before check engine lights were created.

Most states that have inspection you need the light to work

Ah, thanks for pointing that out. I do not (and hopefully will not ever) live in an area that requires state inspections, so I forget about those requirements.

Why would anyone check the line all the way back to the battery? Methinks they know not what they are doing....

Like Mike said, a scan tool like a Tech II would be used to turn all I/P lights on....

Since that garage obviously did not have one, they would have to remove the cluster, attach a test light to the fuse and control circuit in the harness to the cluster...then turn the key on....the test light will then come on when you turn the key to on....if it doesn't, you check the fuse circuit.....if ok, you check the control circuit back to the PCM or BCM, whichever is the controller...another thing they could have done was reattach the harness to the cluster turn the key on, and pierce the control line with a jumper to ground....this would turn the light on if the bulb and circuit inside the cluster was ok....you would need a diagram of the harness to the cluster to test this yourself.....

You should be constantly checking for codes on your vehicle, to see if any are set, if you hsve no SES light....

^ If and only IF that light was on its own circuit. I got $5 that says everything on the cluster is data and not analog signals.

Would the be $5 Canadian? I know where you got it from.