20 LS430 − NEW FEATURES Flex Lock-up Clutch Control In addition to the conventional lock-up timing control, a flex lock-up clutch control is used. In the low-to-mid-speed range, this flex lock-up clutch control regulates the solenoid valve SLU to provide an intermediate mode between the ON/OFF operation of the lock-up clutch in order to improve the energy transmitting efficiency in this range. As a result, the operating range of the lock-up clutch has been increased and fuel economy has been improved. The flex lock-up clutch control operates in the 3rd, 4th, 5th and 6th gears in both D position and S6 range, 3rd, 4th and 5th gears in the S5 range and 3rd and 4th gears in the S4 range.
2 ECM Engine CPU Transmission CPU Engine Speed Throttle Position Sensor Engine Speed Signal (from Crankshaft Position Sensor) Vehicle Speed Input Turbine Speed Signal Duty Ratio Linear Solenoid Signal Input Speed Sensor Time Engine Coolant Temp. Sensor Lock-up Control Valve Solenoid Valve SLU ATF Temp. Sensor 232CH142 Flex Lock-up Operation Gears in Each Range Lock-up Operating Range Large Flex Lock-up Operating Range Throttle Opening Angle Vehicle Speed High Flex Lock-Up Timing in 6th Gear 259LSK21 Position or Range Gear D, S6 S5 S4 1st x x x 2nd x x x 3rd 4th 5th — 6th — —