THANKS GRANT!

yes, I followed the GM factory diagram for the TB connector. Plus...the codes are the same from before and after i repaired the harness.

 

Then both the brown and yellow wires should be 0V because REP will be triggered and power to the throttle motor shuts down.

Did you test for continuity and shorts between wires in the throttle harness? (TAC module to TB)

 

0 volts on brown. 1.6 volts on yellow...

I have not had time to test for shorts. the shop was only open for a half day on saturday.

voltage goes to 0 on yellow with both TAC connectors removed....is the PCM sending the voltage???

once i get my eyes on the wiring diagram, I can test the TB harness wires....

 

Seems to me that you may have tried a different TAC module before. If not, do you get the same readings with another TAC module?

 

This first came up during the burnout of my 10th pass at the track a couple months back.

 

I did swap TC modules...happened to be an 04 HD in the shop this weekend with the same p/n TAC module.

it did not make any difference.

One interesting thing with the diagnostic notes....is that some of the codes don't clear. I may try to get them cleared with a TECH2 and try that 04 TAC again


Anyone want an almost-running truck for cheap? lol

 

Did you check the TAC module ground circuit to the lug on the firewall as well as the engine ground to firewall?

The yellow/brown wires would be connected to the throttle motor drivers in the TAC module - there is no direct connection to the PCM.

 

I have not gone through all the grounds yet...that's on the menu for this week.