I have a 2004 Silverado 2500 with the dreaded TPS codes. I have replaced the throttle body, wire harness TPS and the TPS sending unit on the main gas pedal. The codes are still showing up sporadically. I have checked all grounding and reworked those. I am at a loss and very frustrated. Can someone please help. Cannot find any pattern to the codes. Will run fine for weeks and then throw the codes 3 times in one day. Ready to leave this Chevy behind. At the same time i am getting some U codes. Not sure if it’s related

 

P0120 TP sensor 1 voltage is less than 0.325 volt or more than 4.75 volts for more than 1 second. your case it is likely HIGHER, P2135 The difference between the TP sensor 1 and TP sensor 2 exceeds a predetermined value for more than 2 seconds. Its likely a corrosion issue in your wiring or connectors. Try some dielectrical grease and see if that helps you out.

 

Sorry to be dense but put a small amount of grease on the plugs before plugging in? Thanks for the information. Could not find specific specs to check. I will take a look at those this week.

 

Not chassis grease, Dielectrical grease. It's made so that it doesn't conduct electricriy. It will keep corrosion, water, dirt and other things out of your electrical system. You can buy it at any auto parts store. Its clear colored. It's in bottles, or even small squeeze packs

 

Yes. I know what the grease is, was just wondering about the application. I will pick some up tonight before church. Thanks for the help. I appreciate the suggestions.

 

i know it’s been over a year and hopefully you’re still on here. Did you ever find the route to the problem? Because I’m to the point I just wanna light it on fire.

 

Yes. I did. It was actually an aftermarket TPS wiring harness. The harness looked new but was actually loose. I replaced with a factory harness and all has worked great for about a year now.

 

Awesome! I so hope that’s my problem. If you don’t mind me asking where did you pick up the wiring harness at?

 

If it was truly a factory wiring harness then he would almost have to get it from a dealer or from a place like GM Parts Direct online.