The throttle body wiring is a separate harness. It's essentially a 12" pigtail of roughly a dozen wires coming from the throttle body that need to be replaced. I went through this exercise myself (successfully) a few years ago.

The link below illustrates how to fix the wiring in detail.
http://w140repair.com/ETA_Rewire.htmhttp://w140repair.com/ETA_Rewire.htm