The code P0841 is for -LR PRESSURE SWITCH RATIONALITY. The P0700 is a general notice that there are codes in the TCM. To get to those codes you will need a scan tool capable of reading the TCM. Most aftermarket scanners are not capable of doing that and you will need a professional scanner.
The P0841 means that there may have not been enough pressure to perform a shift, there may be an electrical issue causing no shift to take place or a few other items such as a failed PCM. Most likely this will not be an easy repair but the very first thing to check would be fluid level.
After that you will need to find out what other codes are in the TCM because some codes can lead you in the wrong direction without knowing everything that is going on. Most likely you are going to need to drop the pan and inspect for pieces.
The sump filter is a spin on cartridge style filter.
Number 2 is where it is located. Don't have a good side view. Take a good look at the valve body when you drop the pan. Have seen the plate that holds the accumulator pistons break and cause a no shift condition, although usually it is a 3rd gear problem.