Electronic Control Module
WARNING: This page is about a different car, the 2002 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.
The ECM monitors transaxle operation and contains a self-diagnostic system which stores DTCs if a transaxle electronic control system failure or problem exists. A malfunction Indicator Light (MIL) on instrument panel will illuminate to warn driver a malfunction has occurred. DTCs can be retrieved to determine transaxle problem area. See RETRIEVING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM.
ECM receives information from various input devices and uses this information to control shift solenoids and torque converter lock-up. To locate ECM, see Fig 1.