Automatic Transmission Input Speed (A/T ISS) Sensor Assembly (73)
The A/T ISS sensor operates identically to the A/T OSS sensor except it uses the stamped teeth on the forward and direct clutch housing assembly - with input shaft (567) as the rotor (reluctor). Remember that the forward and direct clutch housing assembly - with input shaft is driven at converter turbine speed. The A/T ISS sensor square wave form is also compared to a fixed clock signal internally within the TCM to determine actual converter turbine speed. The TCM uses transmission input and output speeds to help determine line pressure, transmission shift patterns, TCC apply pressure, gear ratios, and TCC slippage for diagnostic purposes.