Auto gearbox

Most probably the car is equipped with the Ford 5R55N transmission. Is the check/service engine light on? If it is, first thing would be to pull the codes that will tell you what the problem is. How many miles in the car? Problems with the transmission are expected in high mileage vehicles. I was checking my shop service manual and it says that gear ratio error codes are very common on these transmissions due to servo pin bore wear occurring at high mileage and, in some cases, even at low mileage.You can have a gear ratio error code without having an electrical code (solenoid), but it is unlikely that you will have an electrical circuit code without a gear ratio error code. You may have to take the car, to a transmission shop for a check up; do not drive over 35-40mph to avoid more damage.