Where is the speed sencor on a 1999 f150?

On a 1999 Ford F-150, the speed sensor is typically located on the transmission. Specifically, it can be found on the rear of the transmission case, near the tailshaft. It's responsible for sending vehicle speed information to the engine control module and the speedometer. If you're having issues with speed readings, it's a good idea to check the sensor and its wiring for any damage.