ECT Operation
OPERATIONCutaway View Of A340E Transmission:
Shift Solenoid Operation:
1. FUNCTION OF MECHANICAL COMPONENTS
Function Of Transmission Components:
2. HYDRAULIC CONTROL SYSTEM
The hydraulic control system is composed of the oil pump, the valve body, the solenoid valves, the accumulators, the clutches and brakes, as well as the fluid passages which connect all of these components. Based on the hydraulic pressure created by the oil pump, the hydraulic control system governs the hydraulic pressure acting on the torque converter clutch, clutches and brakes in accordance with the vehicle driving conditions. There are 4 shift solenoid valves on the valve body. The shift solenoid valves No.1 and No.2 are turned on and off by signals from the ECM to operate the shift valves, and change the gear shift position. The shift solenoid valve SLU is operated by signals from the ECM to engage or disengage the lock-up clutch of the torque converter clutch. The shift solenoid valve SLN is operated by signals from the ECM to control the engagement speed and reduce gear shift shock.
3. ELECTRONIC CONTROL SYSTEM
The electronic control system for the A340E automatic transmission provides extremely precise control of the gear shift timing and lock-up timing in response to driving conditions as sensed by various sensors located throughout the vehicle and in response to the engine's running condition. At the same time, the ECM control reduces vehicle squat when the vehicle starts out and gear shift shock. The electronic control system is also equipped with a self diagnosis system which diagnoses malfunctions for the vehicle to continue functioning when a malfunction occurs.
Construction
The electronic control system can be broadly divided onto three groups; the sensors, ECM and actuators.
System Schematic
Transmission Control System Schematic:
Components, Location And Function
Transmission Control System Components - Location And Functions:
