Where does the knock sensor plug in?
 

I know this is a stupid question, but I've been having a few problems, and today I noticed my knock sensor wasn't plugged in. And there are a few other plugs around it that could fit it.

Does it plug into the engine wiring harness, or the body wiring harness that has the ignition plugs in it, etc? Any help would be great.

Engine wiring harness. The connector is located by the CAS connectors I think.

underneath the back side of the alternator

Allright guys, thanks.