HelloCustomer I'm Chris, a current Ford Lincoln Mercury employee.
Thanks for visiting Just Answer. I will do my very best to help you resolve your concerns
If it was shifting correct before but not know then odds are you need to adjust the shifter to make sure its in drive and not manual 2nd and you need to make sure the TR sensor is plugged in and no wires are damaged and check the solenoid connector as well. Also look at the top of the bellhousing to make sure the trans wire harness is not smashed between the engine and trans.
Beyond this codes will need to be checked and then internal concerns have to be suspected.
where is the TR sensor located? also are there places where I can get an electronic diagnostic for free?
Auto Zone is about the only place that can scan one for free. But I have heard they cant do transmissions which I find odd since the codes for engine and trans are stored in the same module.
The TR sensor is o nthe drivers side of the trans near the pan.