Codes P0877 and P0989, where are the two sensors located?

Is the transmission full of fluid? This can cause these codes here is the transmission pressure control switch location and how to change it out in the diagrams below. It is part of the control solenoid valve assembly. I have also included the transmission wiring diagrams so you can see how the system works. Check out the diagrams (below). Let us know what happens and please upload pictures or videos of the problem.