Chrysler 2005 300C Transmission slipping code 0703
 

I have a 2005 Chrysler 300C 5.7 Lt.Hemi my transmission is a NAG 1 I changed my transmission fluid and filter everything was fine for about 2 weeks and then out of nowhere transmission started leaking so I changed the fluid again and now it brings up code 0703 it says that my 1st and 2nd gear ratio is off what do I need to do to fix this problem that I'm having please help any information would be appreciated