Transmission stuck in first gear?

Hello, I'm Danny.

You should first check the transmission fluid level. Here is a tutorial showing how to check and add transmission fluid:

https://www.2carpros.com/articles/how-to-check-and-add-transmission-fluid

The next thing for you to do is perform a CAN scan. A CAN- Controller Area Network scan will test and retrieve all codes that are stored in your vehicles computer. This scan will test all systems on your vehicle including the transmission you mentioned. Here is a tutorial showing how to perform this scan:

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

After you perform this scan get back to us with any fault codes and we can then properly diagnose all the issues with your the transmission on your Stratus. Hopefully there is no internal damage to your transmission or that would require a complete transmission rebuild. I've attached the transmission type fluid below. Hope this helps and thanks for using 2CarPros.