3239342 - E3050 ELECTRIC FRONT WINDOWS - Functional description

Functional description

The integrated services control unit M40 manages the operation of the electric front windows. The direct supply from the battery for control unit M40 specific to the electric windows (pin 15 and 16 of connector A) arrives from the line protected by maxifuse J/B1 (of B5 up to 2/99 or B99 from 2/99) and fuse F12 of junction unit B1 , while the supply controlled by the ignition reaches pin 7 of connector B from the line for fuse F1 ; pins 4 and 20 of connector A provide the reference earth for the passenger and driver's electric windows, respectively. The switches H40 (driver's electric window), H41 (passenger electric window on driver's door) and H50 (passenger electric windoe on passenger front door) receive a supply controlled by the ignition (INT/A) from the line from fuse B10 up to 2/99 or from fuse F6 of the additional fuse box B98B from 2/99, and are earthed C20 : in this way they are also lit up when the ignition is switched on.

When the switches are operated, they send control signals (positive and negative) to control unit M40:

  • at pins 10 and 11 of connector A from switch H40 ;
  • at pins 5 and 18 of connector A from switch H41 ;
  • at pins 2 and 6 of connector A from switch H50 ;

The control unit M40 operates the electric windows on the basis of the logic described previously:

  • from pins 8 and 9 of connector A it sends commands to the driver's electric window motor N60
  • from pins 1and 3 of connector A it sends commands to the passenger electric window motor N61.
When the positive and negative signals are reversed, the motor's direction of rotation is also reversed.