The upper forward sensor is connected to the throttle cable input by a shaft that runs through the casting, it only connects these two items no other connection internally. The lower rearward sensor is connected to the throttle butterfly shaft to tell the ECU the shaft position. I would not recommend taking apart your only throttle body. Lots of parts inside, motor, circuit board, gears, levers, sealed set screws for shaft limits. The butterfly shaft is two pieces. Seems to be a number of people with the code and no real definitive cure yet.