Lock Up Control and Slip Control
Based on the output speed signals, signals from the ECM (engine speed and throttle opening amount) and the vehicle speed, the lock up control solenoid (SLU) is linearly controlled to perform the lock up control smoothly. In addition, the slip rate of the lock-up clutch is detected by monitoring input speed signals and slip control is performed.
By allowing the lock-up clutch to slip when lock-up is OFF, slip control extends the lock-up range into lower vehicle speeds. This suppresses a rise in the engine speed and increases transmission efficiency, improving fuel economy. At the same time, through the slipping of the lock-up clutch, engine speed fluctuations can be absorbed by the torque converter.
| Control | Description |
|---|---|
| Lock-Up Control | This control is performed using a lock-up control solenoid (SLU). The lock-up control solenoid (SLU) is linearly turned ON and OFF, the lock-up clutch inside the torque converter is operated and the pump impeller and turbine runner are connected. This enables the coupling of the engine and the automatic transmission. The engine output is transmitted directly to the automatic transmission, eliminating transmission losses and enhancing fuel economy. |
| Slip Control | This control is performed using the lock-up control solenoid (SLU). The lock-up control solenoid (SLU) is linearly turned ON and OFF and the lock-up clutch inside the torque converter is operated outside of the lock-up range. The lock-up clutch slips without being completely engaged, increasing transmission efficiency and enhancing fuel economy. However, as the lock-up clutch is slipping, the specified ATF must be used in order for lock-up control to operate correctly. |