2017 fuel rail harness needs replaced. Original P/N 12629928, new harness 12690531. The cannon plug going to the fuel sensor assy has three wires, Brown Gray and yellow. The brown and gray wires are reversed on the new harness and the yellow remains in the middle. Yes outside wire colors are flipped. According to VIN this harness should work but as you know this is a hard job and would like to know if this is going to be an issue before I start reassembling.
Thanks for the help.......I hope

I am assuming the original harness is from the factory. Correct me if I'm wrong here.

Is the new part an ACDelco or Delphi part? . . . or some third party?

Does the seller of the part have a review process where you can find out about this type of headache on the same part by skimming the reviews?

Who is the seller?

Looking around a little, I can find 12629928 but can't find 12690531 . It could be that the new version hasn't yet propagated out to the masses yet, which tells me that maybe you bought yours from a dealership . . . ?

Part from GM OE, talking with dealership they say that is the part they would order to replace. Sooooo......... I went ahead and installed everything and now need to complete the system priming. still looking for proper procedure.
Thanks

2017 probably doesn't have a fuel return line. I think those will prime by turning it over for a few seconds a few times.

so guess what , the harness was wired incorrectly and I had to fix that issue. Assembled in Mexico..............................says it all.

Wow, not something we've heard much of here, but I have heard that it happens.

Thanks for letting us know how it turned out!

I thought it might be helpful for someone else in the future. Trust your instincts and do a deeper dive to verify. I should have done so. Just glad I found the problem.
Thanks for the reply