P1774 is not a valid OBD-II code for Fords. In fact, I don't see it listed for any other manufacturers, either.
http://autorepair.about.com/library/ts/obd-ii/bl-obd-17.htm
P1774 is in fact a transmission code (P=powertrain 1=enhanced 7=transmission 74=setting condition [variable]), but 74 is a specific code that I can't find. If you're sure that's what you were told, maybe you could try taking it to Autozone for a second opinion on the code you're getting.
After driving around for a while, put the car in park, keep it running, and check the tranny fluid. If the level is below minimum, try topping off the fluid and see if that helps (hopefully you can catch it before anything's damaged). If the fluid is brownish (should be red) and smells like its burnt, you probably have a toasted tranny. Prepare to bend over for a replacement.
