problems

ok I keep on getting this passkey system fault, and well its causing alot of problems, my speedometer keeps jumping around, so does the tach, the tranny drops into a lower gear then speeds up to get into the higher gear whether in any driving mode such as cruise on a flat road for hundreds of miles, then the speedometer stops working and looks like im going 140 and the temp gauge stops working. There is def a electrical problem, and also the car doesn't start, doesn't turn over, just sits ther like the clean key wait 3 min thing pops up, but I believe its the nuetral safety switch but I dont know since all these other problems are happening, i relplaced the starter, battery ignition switch. Pain in the butt and Im sick of it. can anyone help.

Sounds like it is probably a grounding issue somewhere. Try and find out the factory grounding points and tighten them.