Taurus Transmission Problems

Sounds familiar! I had similar automatic transmission issues with my Ford Taurus: implausible shifting and the light coming on. I read that undervoltage in the car's electrical system can mess with the transmission's computer. Have you had any other electrical weirdness, like lights dimming or the radio cutting out?

Interesting! I haven't noticed dimming lights, but the radio did act a little strange a couple of times. What exactly did undervoltage do to your transmission, and how did you fix it?

I'm no mechanic, but undervoltage can cause the transmission control module to get wonky readings, leading to shifting problems. I didn't try to fix it myself; I took it straight to a workshop. They ran diagnostics and confirmed the undervoltage issue. They suggested replacing the oil and checking all electrical connections. Getting it checked out by a pro is probably your best bet.

Thanks a bunch for the advice! I took it to my mechanic, and you were spot on! It turned out that the transmission oil was completely worn out, likely due to undervoltage somewhere. They replaced the oil, and now it's shifting like new. The total cost was around 240€ I really appreciate the help!