Gen IV harness. What's this plug?

[bigmoe]

I've got my motor ready to go into my truck. Thought it would be easier to put the harness on before it's in the engine bay. It's a Gen IV 08 5.3. I can't figure out what the purple plug is for on the left of the picture. It's at the same end as the big plugs for the ECM. It's on a fairly long lead. I assume it's goes somewhere off the engine. (The picture is not my harness but a pic of PSI's harness.) Not seen on the right side is the OBD II plug.

[bigmoe]

Oh crap! It's for the gas pedal. I knew I should know where it went!
My ECU is going on the drivers inner fender. I'm trying to hide some of my wiring and keep it as neat as possible. It's too bed this gas pedal wire doesn't come out of the harness on top of the engine at the back where it could be routed in through the firewall by the pedal.