P0120

[RGreco77]

Hey Guys,

 

Since the snow started in NY, my truck has been throwing a check engine light after using my scanner to read the code it tells me a P0120, when the CEL comes on the truck remains running the same with no visible issues, cleared the code, continued on my way for the CEL to come back on same code.  The CEL does not come on immediately but after a few hours or a day.  Not sure what to do ? any suggestions.  As information it is a 2008 GMC SIERRA DENALI 6.2 Liter

[carnau]

14 hours ago, RGreco77 said:

Hey Guys,

 

Since the snow started in NY, my truck has been throwing a check engine light after using my scanner to read the code it tells me a P0120, when the CEL comes on the truck remains running the same with no visible issues, cleared the code, continued on my way for the CEL to come back on same code.  The CEL does not come on immediately but after a few hours or a day.  Not sure what to do ? any suggestions.  As information it is a 2008 GMC SIERRA DENALI 6.2 Liter

I love 120 codes. They make me feel all warm a fuzzy inside.

DTC P0120 - Throttle Position (TP) Sensor 1 Circuit

 

First, lets start with this. Check your battery. I have seen low voltage problems cause this many of times.

If your battery is good. (load test the battery not just checking voltage)

 

With the codes cleared go to your throttle body while the truck is running wiggle/manipulate the harness and try to get the code to come on. If it comes on replace it with http://amzn.to/2mbF3mY

 

If you can't get it to come on (I still would replace the harness myself lol) but clean the throttle body assembly and see if the code comes back. If it does we will have some electrical diagnosing to do (which I can walk you through pretty easy)