BlueMaxCougar

I have a 2005 GMC C5500 with an 8.1L engine. Using my scan tool, I initially determined I had a bad TAC module (throttle actuation control) I replaced it twice with no data changes. I changed the Throttle body with a new unit and electrical connector. Still no changes. The throttle body plate moves, but just barely. It makes a hell of a noise grinding and clicking when the throttle pedal is pressed any amount. I can't get the 5v reference to come up. Here's a couple screen shots of idle data and wide open throttle. Any help would be appreciated. Almost forgot, codes are P0120 and P2135

Throttle closed


Wide open