LS430 − NEW FEATURES 18 10. Electronic Control System General The electronic control system of A761E automatic transmission on the ’04 LS430 and the A650E automatic transmission on the ’03 LS430 are compared below. (Continued) System Function ’04 LS430 ’03 LS430 A761E A650E Shift Timing Control The ECM sends current to the solenoid valve S1, S2, S3, S4 and/or SR based on signals from each sensor and shifts the gear. — The ECM sends current to the solenoid valve S1, S2, S3 and/or S4 based on signals from each sensor and shifts the gear.
— Clutch Pressure Control (See page 45) Controls the pressure that is applied directly to B brake and C clutch 2 3 by actuating the linear solenoid valves SL1 and SL2 in accordance with the ECM signals. The solenoid valve SLT and SL1 minutely controls the clutch pressure in accordance with the engine output and driving conditions. — To achieve smooth shifting, the solenoid valve SLN controls the accumulator back pressure in order to finely regulate the hydraulic pressure that is applied to the clutch. Uses the solenoid valve SLU to directly control the hydraulic pressure that is applied to the clutch.
— Line Pressure Control (See page 46) Based on the throttle opening angle and various signals, the ECM sends a signal to solenoid valve SLT to generate line pressure according to the engine output and to effect a smooth gear shift change. Engine Torque Control Retards the engine ignition timing temporarily to improve shift feeling while up-or down-shifting. High Response Shift Control Though the cooperative control with the ETCS-i (Electronic Throttle Control System-intelligent), and the electronic control of supply and discharge speed of the clutch and brake hydraulic pressure, excellent response has been realized.
Lock-up Timing Control (See page 46) While in the top gear when the shift lever is in the D position or 4 range, the ECM sends current to the shift solenoid valve SLU based on the signals from the sensors and engages or disengages the lock-up clutch. — While in the 5th or 6th gear when the shift lever is in the D position or S6 range and in the 5th gear when the shift lever is in the S5 range and in the 4th gear when the shift lever is in the S4 range, the ECM sends current to the shift solenoid valve SLU based on the signals from the sensors and engages or disengages the lock-up clutch.
— Flex Lock -up Clutch Control (See page 47) Controls the solenoid valve SLU, provides an intermediate mode between the ON/OFF operation of the lock-up clutch, and increases the operating range of the lock-up clutch to improve fuel economy. The flex lock-up clutch control operates in the 3rd, 4th and 5th gears in the D position. — 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. —