Power Windows Position Recognition

Direct Recognition:

Function
The shaft of each of the power window motors (M10/3, M10/4, M10/5, M10/6) is equipped with two Hall sensors (b1, b2). These Hall sensors respond to the movement of the magnets and each transmits one square-wave pulse for each rotation of the motor shaft. The respective door control module ( N69/1, N69/2, N69/3, N69/4) receives these pulses and interprets them to recognize rotation direction and position.


NOTE: Model 203.7 has no rear door control modules or power window motors.


Direction recognition
From the time difference between the pulses from Hall sensor b1 and the pulses from Hall sensor b2 the relevant control module recognizes the rotation direction of the power window motor.

Position recognition
The control module counts the pulses sent by the second Hall sensor, taking account of the direction of motor rotation. The value in the position counter is reduced when the window doses. When the window opens the position counter value rises.The zero position is defined as the upper mechanical limit stop, i.e. when the window is fully closed the counter should be at zero. The zero position is set through normalization. If the zero position is exceeded in the close direction, the count becomes negative, and thus invalid. In this case the control module performs a renormalization.