Function of Power Window Position Recognition Feature

Recognition Of Direction Of Rotation Of Front Power Window Motors:

Front power windows

Recognition of direction of rotation
Two Hall sensors b1 and b2 are located on the motor shaft. They react to the motion of the magnets. When the motor rotates one turn each of the Hall sensors outputs one square wave pulse.

The corresponding door control module (N69/1) or (N69/2) reads in the pulses from the Hall sensors. The door control module recognizes the direction of rotation of the motor from the chronological offset in the pulses from Hall sensor b1 and those from Hall sensor b2.

Position recognition
The corresponding door control module counts the pulses from the Hall sensors depending on the direction of rotation recognized for the power window motor. The value in the position counter is increased when the window closes. In the other direction the value in the position counter is reduced as the window opens. The upper lockout point is defined as the zero position, i.e. when the window is completely rolled up the counter should be set to zero. Setting the zero position is accomplished with the synchronization function. When the zero position is exceeded in the opening direction the counter status is negative.

Rear power windows

Recognition of direction of rotation
A feature for recognition of direction of rotation is not present, the direction of rotation is always determined by the polarity of the motor.

Position recognition
The position recognition feature for the rear side windows is limited to recognition of the top-most and bottom-most positions, intermediate positions are not recognized. The rollbar/soft top operation control module (N52) measures the current consumption of the left rear power window motor (M10/5) and right rear power window motor (M10/6) during operation. When the rear side windows reach their bottom-most/top-most position the current increases highly in each of the motors resulting from the windows locking up. This allows N52 to recognize the end positions and switch off the motors.