Power window position recognition, function - GF72.29-P-4000PP

2006 Mercedes Benz C350 4MaticSECTION Power window position recognition, function - GF72.29-P-4000PP

MODEL 203 

Direction of rotation recognition 

Fig 1: Direction Of Rotation Recognition Graph
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Operation 

At the shaft of the:

  • Left front power window motor (M10/3)
  • Right front power window motor (M10/4)
  • Left rear power window motor (M10/5)
  • Right rear power window motor (M10/6)

there are two hall sensors each (b1, b2). These Hall sensors respond to the movement of the magnet and each transmits one square-wave pulse for each rotation of the motor shaft. The corresponding:

  • Left front door control module (N69/1)
  • Right front door control module (N69/2)
  • Left rear door control module (N69/3)
  • Right rear door control module (N69/4)

senses these pulses and evaluates them for recognition of the direction of rotation and position.

Direction of rotation 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 of the position counter is reduced when the window closes, when the window opens the value in the position counter is increased. 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 synchronization. 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 resynchronization.

IMPORTANT Model 203.7 is not equipped with rear door control modules or power window motors.

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RENDER: 1.0x

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