Dead Power Seat in GMC Yukon, Common Failure Points

Had the same issue on my 2015 GMC Acadia last winter. The passenger seat wiring turned out to be the main culprit, water had gotten into the harness connector under the seat and caused corrosion. Initially suspected the seat motor since both directional adjustments failed simultaneously, but the diagnostic revealed the wiring harness was completely compromised. There was visible damage where the wires flex when adjusting the electric seat position. The repair involved replacing the entire seat wiring harness and cleaning the connector points. The car seats in these GMC models have a common weak point where the wiring bundle can rub against the seat frame over time. Once moisture gets in, corrosion spreads quickly through the harness. This was a substantial repair that took several hours since the passenger seat had to be removed to access and replace all affected components. The issue would have gotten worse if left unaddressed, potentially affecting other electrical systems. Would strongly recommend having it properly diagnosed rather than just replacing parts. The symptoms match exactly what I experienced, complete failure of all seat functions and an error code. A qualified technician can test the seat motor and wiring to pinpoint the exact failure point.

Thanks for sharing your experience. That definitely sounds similar to what I am dealing with on my Yukon. The complete seat failure and error code match up perfectly. Mind if I ask what the final repair cost was for your wiring harness replacement? Also curious if youve had any other electric seat issues pop up since getting it fixed last winter.

Thanks for asking about the follow-up. Since seeing the mechanic, my passenger seat has been working flawlessly. The power seats are now functioning perfectly in all directions. The issue turned out to be different from what I initially thought, it wasnt the wiring harness but rather a heavily discharged battery that was causing the electric seat malfunction. The total repair came to 290 Euro, which included diagnostic time and battery replacement. The seat switch and all seat wiring checked out fine during testing. Its been about 8 months now since the fix, and I havent experienced any other issues with the passenger seat or any other electrical components. This repair was actually much simpler and less expensive than the wiring harness replacement I was initially expecting. The technician explained that a weak battery can sometimes cause power seats to stop working before affecting other electrical systems.

Thanks everyone for the insights. I finally got my Yukon checked out at a different shop. The automotive seat issue ended up being a blown fuse and corroded connector under the passenger seat, much simpler than I feared. Total repair was 180 Euro including parts and labor. The mechanic showed me where water had leaked through a floor seal and caused the electric seat connector to corrode. They cleaned all contact points, replaced the fuse, and applied dielectric grease to prevent future issues. The power seats now work perfectly again in all directions. Definitely glad I asked here first and went to a new shop. The seat adjustment is smooth now and no more error codes on the dash. Will keep an eye on that floor seal to prevent water getting in there again.