Mohammed Ali

I was driving on the high way at 80 m/hr and suddenly the car jerked and down shifted to 2nd and stuck on. CEL, D light and VSA light all came on blinking, swutched off the engine and started it again and I was able to drive for 3 mins without trouble the shifted normally and no blinking lights but then the same issue happened again.Parked at home I tried out a simple method to pull the codes by jumping the OBD 2 port using piece of wire. I got 2 codes from CEL and D light, one eaach.
CEL code 70
D light code 76
I had to change car battery and since the codes disappeared but the car still slips between gears though it has never down shift and stuck on low gears, please help