Engine Speed Signal
WARNING: This page is about a different car, the 1996 Suzuki Esteem. However, it is still accessible from the selected car via links, so may be relevant.
TCM receives an engine speed signal from the ignition system noise suppressor filter, located in circuit between ignition system and TCM. To monitor Torque Converter Clutch (TCC) efficiency, engine speed signal is used to calculate actual transaxle gear ratio by comparing engine speed with vehicle speed (input/output ratio).