Are you sure it's a transmission code?
It might be that it's referring to the Heat/AC selector. Do you have a manual or automatic climate control head and if it's automatic do the lights blink each time you start the vehicle?
The advise is FREE, you get what you pay for!
'95 850 Wagon, 2.3 Turbo, auto, 298K mine since 254K
OBX angled turbo back, 55psi FPR, MSD coil, AC Delco Plat plugs, Delco BCS, -1.5" sport springs, Bilstein/KYB, 25% E85 mix.