A very common cause of the flashing, green M&S lights is low voltage. Fery is correct that there are 17 transmission faults that can trigger the flashing M&Ss and replacing the (expensive) XYZ switch without getting the diagnostic codes read is just throwing money at the problem blindly. Check the battery and alternator voltages.
'99 DII, STI wires, Champion 7070s, '04 CDL & SLABS, Garvin WILDERNESS rack, painted headliner, air springs victim, headgaskets at 109,000, plus victim of XYZ (twice) and many other ridiculous DII failures. Option B AMIGO FREE since February 2011.
Runs like a top; now if I could just afford the gas! December 2014 update - Wait, I can afford the gas! Drill baby, drill!!!