Lock-Up Solenoid, SLU
The lock-up solenoid (SLU) is located on the transmission control system, which is fitted on the front edge of the transmission. The lock-up solenoid consists of an electrical coil that controls a hydraulic valve. The solenoid is controlled with a pulse width modulated (PWM) voltage and is grounded via the transmission control module (TCM). The control module regulates the lock-up engagement of the torque converter. During lock-up, the solenoid is pulsed in, which makes lock-up engagement gentle. The solenoid allows the torque converter to work in one of three modes: "open", "controlled slippage" and "locked". The solenoid has a linear hydraulic function.
The solenoid can be diagnosed.