Pattern Select Switch Power Mode Circuit: Description
WARNING: This page is about a different car, the 2007 Lexus IS 350. However, it is still accessible from the selected car via links, so may be relevant.
Cowl side J/B ECU receives pattern select switch information, and sends it through the multiplex communication system and CAN system to the ECM.
The ECM memory contains the programs for the NORMAL and POWER shift patterns and lock up pattern.
By following the programs corresponding to the signals from the pattern select switch, the neutral start and other various sensors, the ECM switches the solenoid valves ON and OFF, and controls the transmission gear change and the lock up clutch operation.