ATF Temperature Sensor
WARNING: This page is about a different car, the 2002 Toyota ECHO, 2002 Toyota Celica, 2001 Toyota ECHO, and 2001 Toyota Celica. However, it is still accessible from the selected car via links, so may be relevant.
ATF temperature sensor, located on wiring harness inside transaxle oil pan, converts fluid temperature into a resistance value, which is input to ECM. See Figure.