2004 Lexus LS 430 User Guide - Page 23
2004 Lexus LS 430 Manual
Page 23 highlights
QUICK REFERENCE NOTE: Vehicles with the cruise control: When the cruise control is being used, even if you downshift from "D" or "6" (sixth range) to "5" (fifth range), or "D" or "5" (fifth range) to "4" (fourth range), engine braking will not be enabled because the cruise control is not cancelled. For vehicle speed reduction, see page 324. Vehicles with the dynamic radar/laser cruise control: When the cruise control is being used in the conventional (fixed speed) cruise control mode or in the vehicle-to-vehicle distance control mode, even if you downshift from "D" or "6" (sixth range) to "5" (fifth range) or D", or "5" (fifth range) to "4" (fourth range), engine braking will not be enabled because the cruise control is not cancelled. For vehicle speed reduction, see pages 354 and 339. 5