My dad was a master mechanic and he just passed away last January. This is something he would have fixed. With your video I was able to do it myself. Thank you.
(Technical Service Bulletin)TSB- 19-NA-206 as an update from 18-NA-297/ Please follow the link and read it all the way through- static.nhtsa.gov/odi/tsbs/2019/MC-10166630-9999.pdf/ if the harness does not work then it will need a new shifter assy. (Part number for the wiring harness ASM-A/TRAS CONT is 84733196
This may be it. Have the dealer parts department check your cars VIN and production date before you buy it. (SWITCH ASMA/TRNSCONT(2016-2018 Malibu/Acadia/ Traverse) ****Part Number 84955381***) static.nhtsa.gov/odi/tsbs/2021/MC-10199243-9999.pdf