I have a 2016 Yukon Denali throwing PO700 and PO711. Very rough shifting and stuttering. Nowhere on the special extended coverage release does it say 8 speed only. https://static.nhtsa.gov/odi/tsbs/2020/MC-10178408-9999.pdf
I've got the 6.2L V8 with a 6 speed transmission. My dealer is backed up for 6 weeks because they can't get transmission fluid. From the release the fluid required is Mobil 1 Synthetic LV HP Automatic Transmission Fluid 19417577 which I can have delivered to the dealer by Amazon in 3 days. The dealer says GM must source the fluid themselves and will not pay for the repair unless it comes from GM which sounds nuts to me. Anyone else have this problem? Also, can anyone point me to a TSB or other release stating the extended warranty is for the 8 speed only? Thanks