Electric Panoramic Sliding Sunroof, Function - GF77.20-P-0003LF
Model 222 with code 413 (Automatic panoramic sliding sunroof)
Function requirements, general
- No overvoltage or undervoltage
- Transport mode not active
Electric panoramic sliding sunroof, general
The front section of the panoramic sliding sunroof can be opened in the tilt or slide position. Extended roller sunblinds are retracted before the panoramic sliding sunroof is opened. The panoramic sliding sunroof is operated with the roof system switch in the overhead control panel control unit.
Overheating protection:
The panoramic sliding sunroof motor is protected against overheating by a software thermal protection in the panoramic sliding sunroof control unit. This temperature in the panoramic sliding sunroof motor is calculated in consideration of the voltage, current and duration of actuation as well as outside temperature.
The front SAM control unit directly reads in the signal of the outside temperature sensor, calculates the outside temperature and sends it to the panoramic sliding sunroof control unit via interior CAN.
Recognition of switch signals'
The actuation of the roof system switch is clearly detected after 40± 10 ms. The max. actuation duration is 20 s. A defective roof system switch is interpreted after 60 s. A new actuation (triggered via the roof system switch) can only be performed again after detecting that the roof system switch is in the rest position.
There are comfort functions for opening and closing the panoramic sliding sunroof that facilitate a central opening and closing together with the side windows from one control point.
Roof rack
If a roof rack is installed on the vehicle, the panoramic sliding sunroof should not be opened. A roof rack released by Mercedes-Benz has an end stop. This prevents damage where the panoramic sliding sunroof is opened. Once the panoramic sliding sunroof comes into contact with this end stop, the panoramic sliding sunroof control unit detects an obstacle due to the changed power consumption of the panoramic sliding sunroof motor. Actuation is interrupted and reversing is started up to the tilt position.
The electric sliding roof panoramic function comprises the following partial functions:
- Position detection
- Normalize panoramic sliding roof
- Blockage detection
- Automatic reserving function
- Open/close panoramic sliding roof
- Rain closing
- Speed-dependent tilt adjustment
- Memory function
Position detection
The position of the panoramic sliding sunroof is determined by the panoramic sliding sunroof control unit by evaluating the signals of the following sensors:
- Hall sensor 1, panoramic sliding roof
- Hall sensor 2, panoramic sliding roof
The Hall sensors are located offset by 90° on the axis of the panoramic sliding sunroof motor. The position of the panoramic sliding sunroof is determined by counting the Hall sensor pulses. The zero position (panoramic sliding sunroof completely closed) can be set by normalizing.
Additional function requirements for "Normalize panoramic sliding sunroof"
- Panoramic sliding sunroof denormalized
- Panoramic sliding sunroof open (minimum distance to zero position)
Normalize panoramic sliding roof
Normalizing is the basis for assigning the current position to the position of the panoramic sliding sunroof sensed by the sliding sunroof control module. The sliding roof must be completely open for this. Manually close panoramic sliding sunroof with roof system switch until the mechanical end position is reached. Then reactuate roof system switch for min. 1 s. By evaluating the signals of the Hall sensors, the panoramic sliding sunroof control unit recognizes the blockage and sets the corresponding location counter to zero.
Denormalization is performed under the following conditions:
- Voltage interruption during actuation of the panoramic sliding sunroof motor
- Defined movement range is exceeded by 25 motor revolutions
- The defined hall sensor signal sequence is faulty.
- Implausible position of roller sun blind to panoramic sliding sunroof
The position of the panoramic sliding sunroof cannot be determined in the denormalized condition. The function is then limited to manual closing or opening. Actuation can only be performed in steps of 0.5 s.
Additional function requirements for blockage detection
- Panoramic sliding sunroof normalized
Blockage detection
If an obstruction is detected in the closing direction by the position detection, the panoramic sliding sunroof motor is initially stopped and then actuated in the opposite direction. If blockage is recognized in opening direction, the panoramic sliding sunroof motor is stopped and no longer actuated.
Additional function requirements for automatic reversing function
- Panoramic sliding sunroof normalized
- Valid reference data present for automatic reversing function
Automatic reserving function
If the closing of the panoramic sliding sunroof is obstructed or restricted, the panoramic sliding sunroof automatically opens again. The automatic reversing function is based on the comparison of the current rpm of the panoramic sliding sunroof motor with the rpm determined during a teach-in run or adaptation.
If a specific limit value is exceeded during closing during this comparison, the panoramic sliding sunroof control unit evaluates this as an obstruction.
This involves operating all of the closing procedures of the panoramic sliding sunroof in the normalized condition. The panoramic sliding sunroof control module adapts to changes in the power consumption resulting from increased sluggishness (e.g. dirt in the mechanical system).
Where pinching is detected during opening, solely the panoramic sliding sunroof motor is stopped. If pinching is detected during closing, the panoramic sliding sunroof motor is first stopped and then reversed (actuated in opposite direction).
Reversing of 145 mm is performed during automatic closing.
Reversing of 70 mm is performed with the rain closing function.
Reversing of 20 mm is performed during manual closing.
Special case closing panoramic sliding sunroof manually'
If the roof system switch is actuated again in the closing direction within 2 s after the roof is reversed, greater force is applied to close the roof. The next closing attempt deactivates the automatic reversing function.
Additional function requirements for opening/closing panoramic sliding sunroof
- Panoramic sliding sunroof normalized
- Valid reference data present for automatic reversing function of the panoramic sliding sunroof
- Circuit 15R ON or run-on time active (up to t = 5 min after circuit 15R OFF, with front doors not yet open)
- Roller sun blinds open
The electronic ignition lock control unit sends the status of circuit 15 to the panoramic sliding sunroof control unit via the interior CAN. The front door control units transmits the status of the front doors (open or closed) to the panoramic sliding sunroof control unit via interior CAN.
Open/close panoramic sliding roof
The panoramic sliding roof function comprises the following partial functions:
- Open/close panoramic sliding sunroof in slide position
- Raise/lower panoramic sliding sunroof in tilt position
Open/close panoramic sliding sunroof in slide position
The panoramic sliding sunroof is opened or closed for the actuation duration via the actuation of the roof system switch to the first detent. The panoramic sliding sunroof is moved to the last saved position or fully opened or closed via the actuation of the roof system switch beyond the first detent. The automatic operation is canceled by actuating the panoramic sliding sunroof switch again.
The overhead control panel control unit directly reads in the status of the roof system switch. The overhead control panel control unit then transmits this in vehicles up to model year 2018 via the roof LIN, front SAM control unit and interior CAN to the panoramic sliding sunroof control unit.
In vehicles from model year 2018 and later, the overhead control panel control unit transmits the status of the roof system switch via the interior CAN to the panoramic sliding sunroof control module.
The panoramic sliding roof control unit actuates the panoramic sliding roof motor. The automatic reversing function is active during closing. During automatic opening, the automatic reversing function is active in a limited range (protection against risk of pinching from glass cover rear edge/roof rack). Automatic opening and closing of the panoramic sliding sunroof is interrupted when the roof system switch is actuated again.
Additional function requirements for raising/lowering panoramic sliding sunroof in tilt position
- panoramic sliding sunroof completely closed
Raise/lower panoramic sliding sunroof in tilt position
The panoramic sliding sunroof is raised in the tilt position or lowered out of this for the actuation duration via the actuation of the roof system switch to the first detent. An automatic operation starts where the roof system switch is actuated beyond the first detent. The panoramic sliding sunroof is raised to the last saved position or fully raised in the tilt position or lowered from this. The automatic operation is canceled by actuating the panoramic sliding sunroof switch again.
The overhead control panel control unit directly reads in the status of the roof system switch. The overhead control panel control unit then transmits this in vehicles up to model year 2018 via the roof LIN, front SAM control unit and interior CAN to the panoramic sliding sunroof control unit.
In vehicles from model year 2018 and later, the overhead control panel control unit transmits the status of the roof system switch via the interior CAN to the panoramic sliding sunroof control module.
The panoramic sliding roof control unit actuates the panoramic sliding roof motor. The automatic reversing function is active during closing.
Rain closing
The automatic rain closing function prevents rainwater from entering into the vehicle interior. A panoramic sliding sunroof opened in the slide position is fully closed and raised in the tilt position. A panoramic sliding sunroof fully opened in the tilt position is lowered in the case of heavy rain.
Rain closing comprises the following partial functions:
- Rain closing function where vehicle is parked (except code (494) USA version)
- Dynamic rain closing function (during vehicle operation)
Additional function requirements for rain closing when vehicle is parked
- panoramic sliding sunroof opened in sliding position
- Panoramic sliding sunroof normalized
- Valid reference data present for automatic reversing function
- Circuit 15R OFF or vehicle locked
The status of circuit 15 and the status of the central locking are sent by the electronic ignition lock control unit via the interior CAN to the panoramic sliding sunroof control unit.
Rain closing function where vehicle is parked
When it starts to rain, the panoramic sliding sunroof opened in the slide position is fully closed and raised in the tilt position. "Starting to rain" is defined via the wetness of the windshield.
Moistening the windshield is recognized by the rain/light sensor with additional functions. The rain/light sensor with additional functions reads in the signals from the rain sensor directly and evaluates them. The rain and light sensor with additional functions then transmits the request for the "rain closing function" to the panoramic sliding sunroof control unit via the rain and light sensor LIN, front SAM control unit and interior CAN. The panoramic sliding sunroof control unit actuates the panoramic sliding sunroof motor. The panoramic sliding sunroof is adjusted to the tilt position. Monitoring is then no longer performed.
During rain closing, an alarm actuation is suppressed by the interior protection to prevent an unintentional actuation of the anti-theft alarm system (ATA).
The rain closing function is also triggered under the following conditions:
- After 6 h
- In the case of faults in the power supply
Additional function requirements for dynamic rain closing function (during vehicle operation)
- Panoramic sliding sunroof fully raised in tilt position
- Panoramic sliding sunroof normalized
- Valid reference data present for automatic reversing function
- Vehicle speed above 0 km/h
- No activated operation request from panoramic sliding sunroof
Dynamic rain closing function (during vehicle operation)
With the dynamic rain closing function, the raised panoramic sliding sunroof automatically lowers out of the tilt position during vehicle operation in the case of heavy rain. In this connection, the rain intensity and vehicle speed are taken into account.
The activity of the windshield wiper system allows for conclusions on the rain intensity. The windshield wiper system is controlled by the front SAM control unit. In the case of high windshield wiper system activity, the front SAM control unit transmits the "Rain closing function" request via the interior CAN to the panoramic sliding sunroof control unit. The instrument cluster sends the vehicle speed to the panoramic sliding sunroof control unit via user interface CAN, electronic ignition lock control unit and interior CAN. The panoramic sliding sunroof control unit evaluates the data and accordingly actuates the panoramic sliding sunroof motor.
Dynamic rain closing can be interrupted by momentarily actuating the roof system switch and the panoramic sliding roof can be adjusted to any position.
Additional function requirements for speed-dependent tilt adjustment
- Panoramic sliding sunroof fully opened in tilt position
- Panoramic sliding sunroof normalized
- Valid reference data present for automatic reversing function
- Vehicle speed above 0 km/h
- No activated operation request from panoramic sliding sunroof
Speed-dependent tilt adjustment
If the panoramic sliding sunroof is fully opened in the tilt position, it automatically lowers at higher speeds. Depending on the driven speed, the panoramic sliding sunroof is lowered in two stages. The wind noises in the vehicle interior are thus reduced. Where a defined speed threshold is undershot, the panoramic sliding sunroof automatically raises again in the tilt position.
The instrument cluster sends the vehicle speed to the panoramic sliding sunroof control unit via user interface CAN, electronic ignition lock control unit and interior CAN. The panoramic sliding sunroof control unit then accordingly actuates the panoramic sliding sunroof motor.
The panoramic sliding sunroof can be moved again to the tilt position by actuating the roof system switch. The speed-dependent tilt adjustment remains deactivated until the terminals are switched or the roof system switch is pressed again.
Additional function requirements for the memory function
- Roller sunblind and/or panoramic sliding sunroof normalized
- Valid reference data present for automatic reversing function
Memory function
At the end of a manual adjustment, the positions of the roller sunblind and panoramic sliding sunroof are saved in the panoramic sliding sunroof control unit.
During the automatic opening of the roller sunblind and/or panoramic sliding sunroof, the last saved positions are moved to.
| Electrical function schematic for panoramic sliding sunroof | PE77.20-P-2052-97SEA | ||
| Overview of system components of panoramic roof | GF77.21-P-9998LF |