03 Galant 4 speed auto trans problems

Hey guys so I need some help. My transmission decided to poop itself and not wanna work and I have no clue what the issue is. I've already replaced the neutral safety switch which did not remedy the issue. I had gotten a P0705 check engine light code and it jerks very roughly when I go into reverse. My reverse light also don't come on as well. My speedometer also stopped working altogether and my abs light came one as well. Now, this does sound a lot like the car went into limp mode and that there may be a grounding issue( all information read from this post: https://www.thegalantcenter.org/show...-fail-Headache). Swapped out the relays and even unhooked the battery for about 10-15 seconds afterward. Still didn't fix anything. I was wondering if you guys have any clue on what the issue may be and if it is the wiring or look grounds if anybody can get my a wiring diagram(if possible).

Thanks and have a blessed day.