More than likely you have internal transmission issues. These codes are simply telling you that you have a gear ratio error which is most always internal damage as the input and output RPM is not what it is supposed to be in each gear. The fact that you don't have reverse either is just a compounding of the issue.
If it were me, I would inspect the fluid and make sure it is not low and in good condition and if it not, replace the fluid first.
Here is a guide that will help with this:
https://www.2carpros.com/articles/how-to-service-an-automatic-transmission
Below is the process from the manual for this code. The P0700 code is just telling you that you have a transmission code so we need to focus on the testing for the P0731 code.
Please run through this material and let us know if you have questions. Thanks
Images (Click to make bigger)
Friday, May 28th, 2021 AT 5:13 PM
