If your isnt connected, it should connect to a harness between the battery and the engine just below the charge pipe that goes to the TB.
I disconnected mine today to try to troubleshoot my problem and it causes the computer to go into a Open Loop which puts your RPMs to go up, which is related to a problem i have.
I called a local dealship today, the guy i spoke to says it should go to the computer on a manual transmission, which is what i was wondering.