Input Shaft Speed (ISS) Sensor
WARNING: This page is about a different car, the 2004 Suzuki Swift + and 2004 Chevrolet Aveo. However, it is still accessible from the selected car via links, so may be relevant.
The ISS sensor (1) is located on the upper position of the transaxle and detects A/T input speed from the rotation number of the direct clutch drum. They transmit to TCM as a signal.
Courtesy of GENERAL MOTORS CORP.