Input Shaft Speed (ISS) Sensor

INPUT SHAFT SPEED (ISS) SENSOR





The Input Shaft Speed (ISS) sensor is a magnetic inductive pickup that relays information about the transaxle input speed to the PCM/TCM. The PCM/TCM uses this information to control line pressure, TCC apply and release, and transaxle shift patterns. This information is also used to calculate appropriate operating gear ratios and TCC slippage.
The ISS sensor mounts on the transaxle case under the channel plate next to the drive sprocket. An air gap of 0.26 - 2.90 mm (0.010 - 0.114 inch) is maintained between the sensor and teeth of drive sprocket. The sensor consists of a permanent magnet surrounded by a coil of wire. As the drive sprocket is driven by the turbine shaft, an AC signal is induced in the ISS sensor. Higher vehicle speeds induce a higher frequency and voltage measurement at the sensor.
Sensor resistance should be 625 - 725 ohms when measured at 20° C (68° F). Output voltage will vary with speed from a minimum of 0.5 volts AC at 550 RPM, to 200 volts AC at 7000 RPM.