P0674 MISDIAGNOSED! Replaced glow plug with no change! What could it be? 2008 GMC Sierra PART 3?

[@hrdiesel]

Part 1 on this truck is here! ruclips.net/video/09OgdCEsy3k/видео.htmlfeature=shared
Part 2 is here! ruclips.net/video/7TA15WssM1U/видео.htmlfeature=shared

[@515moto]

I wish you were in my neighborhood. I can fix anything but some things I just can't get to

[@waltersweet4595]

How do you get the 2 harnesses off? I have the exact module and need to take this off. 2006 Duramax. What are the locks that undo those harnesses?

[@barrymoore9061]

I get the same exact coding on my 04 with the same cylinder #4. I drive it for about a half hour and the check engine goes out. I have new glow plugs all around and a new control module.

[@hrdiesel]

I would start testing the wiring to make sure there’s not a bad connection somewhere or a broken wire.