The current power window has a ConvenienceFeature function (commonly referred to as convenience control), as long as the click on the power window switch, the power window will automatically drop, and the system will close the door when the electric windows automatically rise. In general, most cars only provide automatic descent system, not to provide the ascending system, for fear of pressing the automatic rise function, the passenger's hand or head if the door glass, the passenger's hand or head will Was caught, so will be a serious injury, in view of this, only to develop a power window over the resistance of the automatic decline system.
    The principle is as follows: electric windows rise, the lower switch is divided into two sections. In the first paragraph, the switch determines the motor to turn or stop the rotation (manual control). When the second paragraph is pressed, the power window will automatically rise or fall to the highest point or the lowest point.
    When the power window switch presses the rising second position, the power window moves to near the highest point when resistance is encountered (about half of the window stroke movement), such as closing the doors and windows when the resistance is greater than 100N (Benz specifications) decline? To prevent the window folder to something. The hand and the head are not caught when moving at the lowest position of the window. So there is no such function in the lowest position, the other window to the highest point if there is resistance to automatic decline function, the window will not be able to close, so the general power window over the resistance of the automatic decline system, only from the opening window 4mm -230mm this time to play a role.
    Circuit Description: When the power window computer CF, while receiving the power window switch up (automatic) and automatic CF signal (second position), the power window computer output current to the electric window motor, the motor up, while the power window computer The power supply to the electric window motor Hall sensor will rise with the motor from the "U" side sent a square wave signal D side to send a negative square wave signal to the power window computer, to know whether the motor running smoothly, when the case The time of the square wave sent by the Hall sensor will be extended to the obstruction, and it is known how much the resistance it receives. When it is greater than 100N, the computer immediately outputs a reverse current to the electric window motor, and the doors and windows are lowered. 55mm and the descending distance is from the electric window motor Hall sensor D side of the square wave sent by the number. You can learn.
    In addition BMWE38.E39 is the use of the top edge of the window pressure bar switch to induction, when the pressure bar switch gently touch, the electric window motor will automatically fall 1-2 seconds
    When the power window computer power is interrupted, there is no automatic lifting function (One-touch) and the power window over the resistance of the automatic drop function The computer must be reset to normal.
    Reset the steps as follows:
    1. Press the first paragraph of the power window switch to move the window to the highest position.
    2. Press the power window switch again to the second segment 1-2 seconds.
    3. Repeat the above steps to reset each window.
    Explore: If you press the power window switch to the first paragraph, and then press the second paragraph, because the second paragraph of the location is to record the point for the highest point position, and this time when the window lift deformation or lift gap is too large , Because the power window over the resistance of the automatic system in the 4mm-230mm role, so when the automatic rise to the highest position, because the gap is greater than 4mm so the power window will automatically decline, maintenance must pay attention to the maximum position when the power window If you have to clear the gap, it is recommended to use a rivet when fixing the lift, not to fix the screw, check the position of the elevator and the window guide to clear the clearance.