2000 grand CARAVAN 0731 code-Tranny

HELP! I HAVE A 2000 GRAND Caravan with a code of p0731 for the tranny. code reads something like 1st gear ratios inccorect? is the common code? it's the only code. happened all of a sudden only 80k on car, did filter and oil tranny change at 72k. all shops are closed for Holiday weekend! i'm stranded~not sure if just a sensor or tranny is gone

replaced both sensors alset

thanks for help