Scanner Doesn't Connect To ECM

98 GP GT 3.8
I had my ecm disconnnted when I was pulling the engine and trans out so I wouldn't damage it. Well now after hooking it back up and connecting the batt my scanner doesn't see it and car won't start and the gauges say the fuel is full (it was only 1\4) and abs is on, DIC is just flashing.

Is there a right way of connecting the ecm back up?

What scanner are you attempting to use?
Why were the engine and trans out?

Double check the grounds at the lowest transmission stud. There should be the neg battery cable and two grounds. Then at the starter there's the battery cable and two hot leads.

They were replaced. My odb2 scanner, thanks i'll check that

yeah sounds like something isnt connected correct. grounds are a good start. i'd look for pinched wires too?