2004 Tahoe Throttle issue

[Fless]

One other thing, the wiring near the throttle body is prone to break; inspect the harness from the TB back a foot or so -- or more if you can -- flexing the wires. They can break or get weak underneath the insulation, not obvious at a glance.

 

[Twithers]

So it's the flat four pin connector, not the square one. I hate that aftermarket connectors don't use color coded wires.
View attachment 358073

I wouldn't change anything at the cluster unless you can determine if it was swapped there.

This diagram (also attached as a PDF) is from Haynes and shows the wire colors (if it's correct) at the top center of the page. (Others here may be able to provide better diagrams from AllDataDIY or somewhere else.) From that you can see which wires are which at the pump, but I don't know if the lineup equates to how they're in the connector. Might want to peel back the harness to see if perhaps the connector was replaced and wired incorrectly. You could also verify that the level sensor ground is the orange and black at the wiring harness. In case you're wondering, the level sensor wires go back to different connectors on the PCM.

View attachment 358074



Lastly, also attached is the pinout of the cluster connector. Hope that helps. Let us know what you do and how it goes.

Thanks for that. I really don't want to have to drop the tank again, unless there's no other way. So, hopefully I'll be able to move wires, if necessary, somewhere upstream.

 

[Fless]

On that question about the throttle position, I have adjustable pedals and I've been told that the sensor on the gas pedal isn't interchangeable with one from a non-adjustable pedal. Is it a big deal to change that? Is it the whole pedal assembly with the sensor in it, or do I remove and replace the sensor on my pedal?

Looking at part numbers, I think you're correct in that they're not interchangeable. I didn't see the sensor sold individually for the adjustable pedals but I didn't look all that hard. You may end up changing the whole pedal assy if you can't get the sensor by itself.

 

[OR VietVet]

It will be the whole pedal assembly and when I did my new throttle body, it was recommended that the wiring harness that plugs in to it be changed at the same time and gave me a part number for it.

 

[Tonyrodz]

Are you sure it's not the throttle body itself? I had a very similar issue a few years ago. Took it to a mechanic and it was the throttle body. Swapped it and no more issues.

 

[George B]

It would be good to have a bidirectional scan too to use for diagnosis.

 

[Twithers]

It will be the whole pedal assembly and when I did my new throttle body, it was recommended that the wiring harness that plugs in to it be changed at the same time and gave me a part number for it.

Was yours with adjustable pedals? If so, would you happen to remember the part numbers for it and the harness?

 

[Twithers]

Are you sure it's not the throttle body itself? I had a very similar issue a few years ago. Took it to a mechanic and it was the throttle body. Swapped it and no more issues.

I'm not exactly sure, but other than this, the truck runs really well. The scanner I used is bidirectional and was showing the throttle position percentage. I'm just not sure yet, if that number comes from pedal position or throttle position. I don't mind changing both parts, if it will fix the problem. I'm just not familiar with this particular system.

 

[OR VietVet]

Was yours with adjustable pedals? If so, would you happen to remember the part numbers for it and the harness?

Yes, adjustable pedals. Pedal assembly-19370279

Pigtail-PT2628

Throttle body assembly-12679525

 

[Twithers]

Thanks