Why is the check transmission light on in my 2005 ford freestyle?

When the check transmission light turns on in Your 2005 Ford Freestyle that means that the transmission control module has detected a fault somewhere in Your transmission. The best thing that You can do is use an OBD II scan tool on the vehicle to read the codes that could be stored in the control module. The transmission in Your vehicle is a very complex piece of machinery and when issues arise the control module will send out a signal to turn on a light at Your dash. The only way to know precisely why the light turned on is to read the codes. It could be something as simple as a loose wire, or something as complexAs damaged gears or synC-HRo rings.