[hatzie]

Don't immediately jump to the conclusion that it's the most expensive or oogie boogie part you can think of.
Unload the Parts Canon and do some diagnosis.
On older vehicles I'd say you blew a fusible link but these don't have fusible links. GM used Maxi fuses instead.
There are four 60A Maxi fuses in the fuse relay panel next to the battery. They're marked BATT 1 - BATT 4 on the diagram. You probably popped one of those.
60A is pretty big. I bet it sounded like a firecracker going off.

 

[hatzie]

GM calls them a "fusible link fuse"
GM 22917199

This is what I'm talking about.

If all four of those are good you need to grab yourself some wiring diagrams.
Specifically you're looking for the power distribution wiring diagram.

Check the main battery power connection on top of the fuse block to the engine with your test light.
Then start checking for volts at the test points on top of the little ATM fuses using the engine as your ground and find out where the power stops.
Keep in mind several of these fuses should normally be powered down with the ignition switched off.

 

[hatzie]

So you shorted the cable connected to the hot on the Impala to the body?

 

[hatzie]

The money light means the ECM is getting power.

You really need the wiring diagrams to figure out a plan of attack. I have the 2009 service manuals but not 2010

 

[hatzie]

A meter is a small load so it will show 12 volts even if the circuit can only pass a few milliamps.
That's why I was suggesting a test lamp on those fuse test points.

 

[hatzie]

You're need to find out where there is power and where there isn't power.

Once you find out where the juice is and is not you can narrow down where the problem lies.

 

[hatzie]

Check your PMs