Coast Control
WARNING: This page is about a different car, the 2002 Lexus GS 430 and 2002 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.
When the SET/COAST switch is kept turned on during cruise control travelling, the engine control module controls the throttle valve to decelerate the vehicle. Every time the SET/COAST switch is turned on instantaneously, the vehicle speed is decelerated approximately 0.93 mph.