hey guys, ive finally replaced my transmission with a working one, but when i started the car i got the check engine light on, so I hood the green cable to the negative battery to check for error codes, but it flashes nothing, the check engine just stays on

has anyone had this problem, ive checked all my cables and hoses, their all good, but hoping if anyone has information on this problem
ive searched but nothing with enough info

 

This is an s5, right?

 

Yes this is an S5 n/a I just thought it was odd that the car would not give me any morse codes
The check engine light is still on and have no ocean why it's still on.

 

When the light comes on are there any other idiot lights that come on? Do the other warning lights work?