Toyota Repair: Two types of speed sensors, speed sensors, engine parameters

Question
There seems to be two types of speed sensors on my 2008 Toyota Tacoma 6 Cly. 4 Wheel drive automatic transmission.

One called a speed sensor (NT) and one called speed sensor (SP2) what does each of them do for the speedometer?

Answer
The NT sensor is located on the transmission housing, this inputs the vehicle speed to the computer and then to the speedometer which makes the speedo work, the SP2 is the sensor inside the speedometer, it sends a signal back to the computer confirming that the speedo is working, the computer then adjusts engine parameters as well as transmission operation such as shift points based on this signal plus other sensors from the engine.