I've got a 2002 Taurus with 260,000+ miles on it and I get the same thing with the flashing transaxle warning light at random times.
What also is confusing is that when I stop at a red light or stop sign the car will start stuttering like it is trying to die and the RPM gauge will start jumping up and down slightly. If I let it sit and idle like this it will eventually start running smooth and then go back to doing it. It does not do this when it's in Park or Neutrel and also does the same thing when in reverse.
I've already replaced the fuel pump and filter, transmission filter and fluid, 2 of the O2 sensors, and the IAC valve. I have a throttle positioning sensor on hand but had a hard time removing it because I couldn't get the two retaining screws loose with a regular screwdriver. If someone else possibly has any ideas it would be greatly helpful. I really don't have the funds to take it some place and get a diags test ran on it but will do it if that's best at this point. Thanks for any help.