note before that I was getting a OBD2 ccode large leak detected. changed gas cap. cchanged purge silonoid. and there was a gas odor evertime I put gas. come to find out my catylac converter was so pluged it turned into dust when I knocked it out. so then thts when my Odometer sttoped working and mmy tranny started to not shift.
The transmission pressure control solenoid may fail causing erratic shifting. Our technicians tell us that partial dis-assembly of the transmission is necessary to replace a failed pressure control solenoid.