Hello, I'm Danny.
If the transmission fluid level is fine and clean Then something mechanical has had to have happened. You didn't mention if the check engine light is on signaling a transmission fault code stored in your vehicle's computer. What I would suggest is performing a CAN scan to have all the systems checked on your vehicle especially the transmission. Here is a tutorial showing what is involved in performing a CAN scan on your car:
https://www.2carpros.com/articles/can-scan-controller-area-network-easy
Once you have this performed get back to us with any transmission codes and we can then help properly diagnose the not shifting issue. Hope this helps and thanks for using 2CarPros.
Jun 15, 2021 at 11:52 PM