4th gear and code49

1993 rodeo starts in 4th gear unless you drive it from first on the shifter then 2nd by manually shifting the automatic. I got code 49 from the TCM and I swapped it out with a junk yard recycle. It worked at first but failed next morning when the wife tried to go to work.

Trans check light flashes sometimes right away and other times not until i try to put it in gear.......

Anybody else have a problem? how do i fix it?

Any other symptoms, irregardless how weird they may be??

sounds like you were going into limp mode aka backup mode. the trans computer does this to protect the automatic transmission when it encounters unexplained problems, especially electrical. this can often be traced specifically to a faulty alternator, or other charging system problems. this is further verified by the tcm diagnostic code 49, which is a supplyvoltage circuit code, which points directly to the battery and/or alternator. voltage needs to be within a very narrow band, >9.1 volts <16volts or the auto trans will act up, whether or not a code is thrown.
why did you change out the tcm?

//bc