DTC = P0720
footnote b = MIL (malfunction indicator light) comes on after 2nd occurance
footnote c = tranny control indicator light (TCIL) flashes
circuit = OSS =
output shaft speed sensor in the tranny (not the variable speed sensor (VSS) in the diff).
condition = OSS sensor circuit malfunction
probable causes = Short/open circuit, sensor, PCM
My guess? Replacing the OSS will take care of it.
I hope you don't have a faulty PCM.