System Components

Sunroof Switch:  Mounted in the sunroof motor trim cover, the switch provides coded ground signals for system operation. The following signals are generated over three wires:

• Rest position.
• Slide open request (press and hold switch - first detent of open position).
• Automatic slide open request (press further to second detent and release).
• Tilt open (press and hold).
• Slide close request (press and hold switch - first detent of close direction).
• Automatic slide close request (press further to second detent and release).
  Fig 1: Identifying Sunroof Switch

  Courtesy of BMW OF NORTH AMERICA, INC.

Sunroof Motor/Module (SHD):  The motor is powered to open, close and lift the sunroof panel. The motor contains two hall effect sensors that monitor the motor shaft rotation providing sunroof panel position.

The hall sensors also provide the end limit cut out function for the SHD once the system is initialized. The SHD counts the pulses and cuts the motor out prior to the detected end run of the sunroof panel.

The combined motor module has a pin connector for interfacing the switch, and vehicle harness (power, ground and Bus.)

The electronic controls and relays are contained in the sunroof module (PM-SHD). The module is connected to the P-Bus (E38 >99 MY on the K-Bus) for comfort closing/opening and diagnosis/fault memory purposes.