The automatic transmission torque converter lock is activated as follows:
1. Increasing engine speed: When the car accelerates and the engine speed reaches a certain level, the ECU (electronic control unit) begins to engage the lock.
2. Oil pressure: The ECU also monitors the oil pressure in the automatic transmission. When sufficient pressure is reached, it is directed to the torque converter lock-up plungers.
3. Plunger Activation: The lockup plungers transmit oil pressure to the lockup clutch located inside the torque converter.
4. Lockup Clutch Engagement: Oil pressure forces the lockup clutch to engage the engine flywheel, mechanically connecting the engine and transmission.
5. Full Lockup: Once engaged, the lockup clutch completely locks the torque converter, eliminating slippage and improving transmission efficiency.
The lock can be activated at different engine speeds and depending on the type of automatic transmission and driving conditions:
*For fuel efficiency, lockup is typically engaged at lower engine speeds under light loads (such as highway driving).
* For better acceleration, lockup can be activated at higher engine speeds under load.