need diy help

2000 kis sephia w/ rebuilt tran., new engine wiring harnesses, inhibitor switch, ECU, range switch-p & spark plugs. won't shift normally, rpm must get upto about 3000 before it shifts to 2nd and won't shift higher. rpms runs high. car slows down right after foot is the off gas. have trouble codes P1624 (tcm to pcm MIL request signal circuit fault) & P0753 (shift solenoid A circuit electrical). please send help my way need to pass safety and really need a better running car.

the 1624 code is nothing to worry about it will go away when you fix the real problem. Has the speed sensor been changed? This is a cheap fix. It has really made the difference in a lot of cases. Also try disconnecting your battery to reset the codes.