Help with getting to the bottom of TPS problems!!

[crhallfarms]

I've been fighting this since 2012. An 05 Chevy Avalanche throwing P0120 P2135. First in 2013 dealer put a throttle body on it, then in 2014 they put new wiring/connector on it! Now over the weekend I got just the P2135 3 times within 50miles. This thing only gets drove 5k a year max, so it only has 10k-15k since new throttle body! This is the first time i'm able to look into this with my efi v2. I mainly use if for flashing diesel tunes and some diagnostics. So how can I check to see whats going on? So before I start throwing parts at it, how do I check the TBS with the v2 to see if its working properly? I checked the connector, shows its good, I'm getting 5 volts from the TAC, im getting a good ground, I checked the output of TPS, getting 1.21V.

[joecar]

Do you have a GM Service Manual for your vehicle...?

Have you seen stuff like this: http://www.obd-codes.com/p2135