Sliding Roof, Function - GF77.20-P-0008GW
Model 463 as of model year 2013 up to model year 2019 with code D27 (Electric tilting/sliding glass sunroof)
Model 463 as of model year 2013 with code F16 (Tilting/sliding sunroof, electric) except code F15 (Sliding sunroof)
Function requirements, general
- Circuit 15R ON
- No overvoltage or undervoltage
The electronic ignition lock control unit sends the circuit 15 status over the interior CAN to the rear control unit.
Sliding roof, general
The sliding roof is a combined sliding/tilting roof. The sliding roof function drops the sliding roof down and moves it backwards into the headliner; the power tilting roof function raises the sliding roof at the rear.
The function is operated using the roof system switch on the overhead control panel control unit or the "Comfort opening/closing via transmitter key" function.
Function sequence for sliding roof
The sliding roof is opened or closed for the time the request is active by actuating the roof system switch to the first catch.
By actuating the roof system switch in the opening direction beyond the first catch, the sliding roof is opened completely.
Vehicles except code E11 (Stealth light with convoy marking):
The overhead control panel control unit reads in the status of the roof system switch directly and sends this via the roof LIN, SAM control unit and interior CAN to the rear control module.
Vehicles with code E11 (Stealth lights with convoy marking):
The overhead control panel control unit reads in the status of the roof system switch directly and sends this via the stealth lights LIN, stealth lights control unit, roof LIN, SAM control unit and interior CAN to the rear control unit.
The rear control unit actuates the roof system open relay for the decel mode or the roof system close relay for the stroke mode. The roof system drive unit is actuated according to the selected actuation direction via the two relays.
The actuation time of the roof system drive unit during automatic opening is limited from 6 to 12 s depending on the on-board electrical system voltage. After this time period the sliding roof is completely open.
The rear control unit directly reads in the status of the roof system forward/backward limit switch and roof system lift/lower limit switch. Reading in these switches serves as fault detection when actuating the sliding sunroof.
The roof system forward/backward limit switch and roof system lift/lower limit switch are not actuated when the sliding roof is closed. As soon as the sliding roof is opened from the closed position to the sliding roof direction, the roof system forward/backward limit switch is actuated. When the sliding roof is opened from the closed position in the stroke direction the roof system lift/lower limit switch is actuated.
Both switches cannot be actuated simultaneously. In this case one of the two limit switches is faulty.
| Function schematic for sliding roof | PE77.20-P-2054-97ZGA | |
| Overview of system components of sliding roof | GF77.20-P-9996GW |