Hyundai Elantra: Input Speed 
Sensor. Description and Operation - Automatic Transaxle Control System - Automatic Transaxle System - Hyundai Elantra MD 2010-2015 Service manualHyundai Elantra: Input Speed Sensor. Description and Operation

Description

Input speed sensor is a vital unit that measures the rate of rotation of the input shaft inside the transaxle and delivers the readings to the Transaxle Control Module(TCM). The sensor provides critical input data that's used in feedback control, damper clutch control, gear setting control, line pressure control, clutch activation pressure control, and sensor fault analysis.