Download DESCRIPTION & OPERATION Convertible top utilizes 6 motors to raise and lower convertible top. Operation of electric motors is controlled by an electromechanical drive system called Top Slack Actuation System (TSAS). TOP SLACK ACTUATION SYSTEM (TSAS) In addition to 6 motors, TSAS system consists of control module, 3 potentiometers, and 7 microswitches. System operates by means of electric motors which are activated by control module, causing top to be raised or lowered. Control module also uses potentiometers to ensure that all movements take place in correct order. When top movement comes to an end, microswitches confirm that top is latched at front and rear, and tonneau cover is latched to the body. If a fault occurs, top movement will be interrupted and a signal will be sent to Saab Information Display (SID), which will sound a buzzer and display an error message.