TPS adjustment failed - shows 19%-73% with throttle sweep

[RecoilFreak]

Greetings! I was driving yesterday with my scanner hooked to my truck trying to figure out my lack of overdrive and noticed my TPS was reading 18% with no throttle input at idle. I shut the truck off and mashed the throttle to the floor - 73%. I purchased a new TPS and installed it - same results (now 19% at idle, 73% at max throttle). I followed the procedure by @Cowboy in the tech articles to check all my throttle linkages. Got the front ball set 5" from the bracket upright. I probed the center lead on my tps harness, set the resting voltage dead on at 1.0v. Voltage at full throttle is 3.73v - within spec according to the tech article. It still reads 19% at idle and 73% at max throttle. This is my first diesel. I've been dreaming of owning a 12v for almost 3 decades. I've got tons of experience with gassers, but I'm at a loss with this issue. Can anyone shed some light on this problem? Anything else I can check? I don't think it would be the PCM since it just came back from ACS with a clean bill of health. Original and replacement TPS do the same thing. Please help a diesel noob out. Thanks!

Edited October 3, 2024 by RecoilFreak