Panoramic Sliding Sunroof Control Unit, Basic Function - GF77.21-P-9891A

Model All (CAR) 

With Code 413 (Panoramic sliding sunroof/glass roof) 

Vehicles with separate control unit 

Fig 1: Panoramic Sliding Sunroof Control Unit Components Location - Model All (Car) With Code 413 (Vehicles With Separate Control Unit)

Courtesy of MERCEDES-BENZ USA

Vehicles with integrated control unit 

Fig 2: Panoramic Sliding Sunroof Control Unit Components Location - Model All (Car) With Code 413 (Vehicles With Integrated Control Unit)

Courtesy of MERCEDES-BENZ USA

Overview 

This document contains information on:

• General 
• Function 

General 

Depending on the vehicle, the panoramic sliding sunroof control unit is either a separate control unit or forms the control module of the panoramic sliding sunroof together with the drive unit. The panoramic sliding sunroof control unit or the panoramic sliding sunroof control module is located on the front roof frame.

• Status of the front doors (open/closed)
• Vehicle speed
• Outside temperature
• Hall sensor signals (of the panoramic sliding sunroof drive unit)
• Hall sensor signals (of the panoramic sliding sunroof roller sunblind drive unit)

The panoramic sliding sunroof control unit is connected to the network architecture of the vehicle. It transmits information on the current position and movement of the panoramic sliding sunroof and the panoramic sliding sunroof roller sunblind via the network architecture.

Function 

The panoramic sliding sunroof control unit controls the movements of the sliding sunroof panel as well as the panoramic sliding sunroof roller sunblind via the electric motor of the respective drive unit and processes for this purpose, among other things, the following information:

• Requirements for actuation
• Signals of the rain and light sensor

Overheating protection 

The panoramic sliding sunroof control unit protects the electric motors of the panoramic sliding sunroof drive unit and the panoramic sliding sunroof roller sunblind drive unit from overheating. The temperature of the corresponding electric motor is calculated by considering the supply voltage, the flowing current, the duration of actuation, and the outside temperature. If the overheating protection was triggered, the actuation of the affected electric motor is disabled for a minimum cooling time.

Exception 

The overheating protection function does not operate during roof reversal (after a blockage is detected).