Ive searched and searched and im still thinking its a ground issue.

ive cleaned as many grounds as i could find and cleaned connections. my tcs light is on and my service engine light is on no abs light. does anyone have a list of all the grounds that deal with tcs and pcm? also some wire diagrams would be helpful.
one more question is what was/is suppost to be under the drivers seat? has data cable and looks like ethernet cable and another rounds connector? im stumped on that one lol. also forgot to mention car starts and drives great.

thanks