i have a 1997 4x4 blazer with 4.3 engine and the electric push button 4x4 auto transmission. i was having a problem going from 4 hi back to 2 wheel drive so i replaced the transfercase control module with a used working one. this did not help the problem. i used the diaganostic procedure to verify that the module is working and it is now i get a check eng light and the codes i pull are po740 tcc circuit malfuntion p0785 shift timing solonoid p1860 transmission control these all come up 2x each. what did i do can anyone please help me.