1998 Civic Si TCM question
 

Good day fellow Civic owners
I just recently bought my first Civic, 1998 automatic SI coupe, for 1500.00. It rode fine on the test drive so I bought it. Now after driving it for more than an hour the 1st gear slips from a start and the check engine light is on. I read codes and got P0700 Transmission control malfunction. Is this fixable with just replacing the TCM? Is there a DIY fix for the TCM? All other gears are fine and shift properly. I don't even know where the TCM is. Any help for a new Honda owner?