4x4player

Trying to fix a 'dead' gas pedal. In my 2004 Chevrolet TiltMaster W4500. 6.0L LQ4 with 4L80E.
Code U0107 lost communication.
This poor truck has over 300K miles. I have replaced the Throttle body/ position sensor, MAP sensor, Purchased another used pedal assembly and pedal brain from running vehicle.
After watching a few YouTube videos and deciding that I'm experiencing ground issues. I ran a 2 gauge ground from the battery negative to frame. 8 ga from frame to cylinder head. 12 ga from frame to throttle body, Pedal brain mount and drilled a hole in the main computer heat sink fin for another ground in 12 gauge. Couldn't figure out how to ground the pedal because its made of plastic.
The gas pedal worked for a short time after replacing the throttlebody. Now, The truck will start and run (roughly) Just no throttle other than idle. I can move the truck in idle.
Found three wires behind the intake manifold bundled in same loom with no connector on end. Two are solid black and other is black with red stripe. Doing a continuity test shows one black wire and the one with the red stripe is grounded,
Also as a side note.. may be related. My gas gauge was all over the place. The needle moved slow up or down sometimes stayed at half way, it couldn't make up it's mind. Now it reads empty period. I guess it gave up.
Throttle by wire sucks! Who's bright idea was this?

The three wires above the transmission housing with the stripped ends.

tech2

for lost communication codes i need to know what module the code is setting in and what module is not being recognized.
ie u0107 set in the pcm lost comm with bcm.

the 3 wires...can you post at pic to where the wires lead to...may help id what they are for? I will do a search and see if the wires in question match anything with the app or throttle body


drive by wire, love it or hate it, was put in place to curb emissions from sudden throttle closing. it also allows faster assembly and less holes in the passenger compartment.

4x4player

Thank you for the "try this"... I'll do that this afternoon.
I'm over 20 years behind when it comes to auto electronics. This is the newest vehicle I have ever owned.
However, I'm determined to fix it myself. Hate paying someone else to fix anything for me.. (strike 1 for Daniel's male ego... lol.)
I posted a photo of the three wires above. Am I the only one who sees it? Anyway, I decided to ground the two solid black wires. They were dangling above where the trans mounts to the engine there is a metal bracket mounted here. Didn't find any broken ring terminals or plastic connector.
The only code I had was the U0107. My scan tool doesn't give me any other information.
Finished with the grounds this morning and hooked up the digital gauges I added also. Started up "Pugly" and it ran rough and rich. Still no throttle pedal. Grr....
Got another code P1125. Throttle position sensor issue. The TPS is new, so I'm assuming its an issue with the plug on the TPS or in the loom. Will check that out next.
I really appreciate your help tech2.

4x4player

Woo Hoo! I can drive 'Pugly' again.
The black wire with the red stripe will keep me up nights, till I figure it out. Couldn't find a reliable wire schematic online, so I purchased a factory manual on disc off ePay.
Thanks again for your assistance tech2