Hello,
I have done some searching of the site and came up empty, likely because my google-fu is weak so let me apologize in advance if this has been answered.

I have a 2020 Blazer that gets an intermittent Shift to Park error. When it happens, the car will not shut off properly, and I have to restart it and slam the shifter into park numerous times to get it to accept that it is in park.

I want to take it to the dealer for repair, but they say that they need to do a diagnostic and it could take days to duplicate the error. This of course will cost a fortune and take God only knows how long. They give me the option of telling them what to do, but they make no guarantee of success. I suppose that I can have them replace the entire shifter assembly and wiring harness, but I don't know if more is required.

I have found an NTSB tech bulletin but it only covers 2019 to 2019 models, so I am hesitant to rely on that. My hope is that some here have had the repair done and can share what the shop did.

Thank you for any help that you can provide.

 

We had the same thing happen to our 2020 Blazer Premier. The solution is to replace the transmission shift mechanism. What caused the problem was the failure of a micro switch, causing the car not to recognize the selector is in PARK. Unfortunately the entire transmission shift assembly has to be replaced. The dealership cannot simply replace the micro switch.