In my 94 I don't know if the fluid has been swapped to mercon 5. I've seen where it's recommended to have the ecm flashed. If I do switch doesn't the ecm need to be flashed? If I don't have ecm flashed what happens?
1997 Mark 8 LSC
1996 Thunderbird lx 4.6
1994 Thunderbird lx 4.6
You don't need to flash the PCM for a fluid change. The calibration change you are referring to is a small change to the TC lockup and slip settings to minimize the infamous shudder, but it's not a required change to have. Plus you'll end up paying a lot from Ford to have it done when you might as well pay a little more to get a custom tune that can improve other things.