My car is starting not to shift right. on 2004 Buick Century

I had my transmission rebuilt about 3 years age. My ABS light is on and my no trac light is on. My car is not shifting right. Sometimes when I would stop and shut the car off for a few minutes it would start shifting again. Could the cause of that be the transmission again or could it be something else.

2 answers 2 comments
yes scan codes and post so we can adv.abs codes can cause many issues
The code came up vehicle speed sensor. The speedometer quit working to.
it could be the transmission modulator on the trans,and that is not expensive...
We tried the speed sensor and it is doing the same thing. Other codes that came up are PO 502, PO503, C1216, C1221, C1225, C1226,C1232, C1233, C1245, C1248. Help I hope this doesn't mean the transmission needs to be rebuilt.