October 23, 2020 

How to fix the intermittent “Shift To Park” issue in the Chevy volt.
First off, there are several videos on how to remove and mess with the shifter knob itself. I totally ignored them as the button on my shifter was not stuck. I believe the issue instead Is an electrical issue that is fixed with a $13 dollar GM part that can be installed in a few minutes with no tools. Don’t be intimidated by pulling up the center consul. It is held in by friction pegs and Easily pops back in to place. You do not break anything by pulling it out as I did in the video.
Chevy realized there was a problem and put out a bulletin on how to fix it. It is 19-MA-206.
Here is the link.
static.nhtsa.gov/odi/tsbs/201...
The part you need cost me $13 on eBay. The GM OEM HARNESS 84733196
Search on eBay for “Chevy part # 84733196”