Cruise Control Switch Circuit: Description
WARNING: This page is about a different car, the 2007 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.
This circuit sends signals to the ECM depending on the cruise control main switch condition.
The battery supplies positive (+) battery voltage to the cruise control main switch. Then terminal CCS of the ECM receives the voltage according to the switch condition.