Modern day torque converters use electro hydraulic Command for your lock-up clutch. The hydraulic circuit which locks/unlocks the torque converter clutch is managed employing hydraulic valves. The valves are actuated directly or indirectly by solenoids. However, Like every mechanical component, torque converters can have on out or malfunction over time. https://torque-converter-clutch53084.qodsblog.com/34002711/the-best-side-of-torque-converter-clutch