Electric Power Sliding Roof, Function - GF77.20-P-0007FG
Model 213
up to model year 2021
with code 414 (Electric sunroof, glass version)
Function requirements, general
- No overvoltage or undervoltage
- Consumer shutoff not active
- Transport mode not activated
Sliding roof, general
Operation occurs by means of the roof system switch in the overhead control panel control unit.
For vehicles as of model year 2018 with code 360 (HERMES UMTS) or code 362 (HERMES LTE), web-based operation of the sliding sunroof is also possible.
The sliding roof is a combined sliding/tilting roof. The sliding roof function lowers the sliding door toward the rear into the headliner. The electric tilting roof function lifts the rear section of the sliding roof.
The sliding sunroof can be operated centrally and together with the side windows from one control point via various comfort functions.
Overheating protection:
An integrated thermal protection switch protects the sliding roof motor against overload.
The sliding roof motor is switched off if the maximum permissible operating time is exceeded.
If the overheating protection function was triggered, actuation is disabled for the minimum cooling time. The overheating protection function does not operate during roof reversal (after a blockage is detected).
The sliding roof function comprises the following partial functions:
- Normalizing
- Position monitoring and blockage detection
- Open/close sliding roof
- Automatic reserving function
- Rain closing
Additional function requirements for normalization
- Circuit 15R ON or run-on time active (up to t = 5 min after circuit 15R OFF, with front doors not yet open)
The electronic ignition lock control unit sends the status of circuit via interior CAN to the sliding roof control module. The front door control units transmit the status of the front doors (open or closed) to the sliding sunroof control module via interior CAN.
Normalizing
Normalizing is the basis for assigning the current position to the position of the sliding roof sensed by the sliding roof control module.
For this purpose the sliding roof must be completely opened.
Completely open the sliding sunroof in tilt position via the roof system switch until the mechanical end stop is reached. The overhead control unit transmits the status of the roof system switch to the sliding roof control module via the interior CAN. Then reactuate roof system switch for min. 1 s. By evaluating the signals of the Hall sensors, the sliding roof control module recognizes the blockage and sets the corresponding location counter to zero.
When normalized, the sliding roof system motor is switched off by the sliding roof module before the mechanical stop is reached during automatic opening and closing.
Denormalization is performed under the following conditions:
- With circuit 30 OFF during actuation of sliding roof motor
- If the sliding roof exceeds the defined movement range
- If one of the Hall sensors fails for 10 signal edges
- If both Hall sensors fail to supply signals for longer than 320 ms when reversing
- With sliding roof actuation when voltage is too low
The position of the sliding roof cannot be determined in the denormalized condition. The function is then restricted to manual closing and opening in increments of 0.5 s each.
Additional function requirements for position monitoring and blockage detection
- Active actuation of sliding roof
- Sliding roof NORMALIZED
Position monitoring and blockage detection
The sliding roof control module monitors the position of the sliding roof by evaluating the signals from the following sensors:
- Hall sensor 1, sliding roof
- Hall sensor 2, sliding roof
The Hall sensors are arranged offset by 90° on the axis of the sliding roof motor. The position of the sliding roof is determined by counting the Hall sensor pulses. The position "Sliding roof in tilt position" is defined as zero position. The zero position is set by normalization.
Blockage is detected if no Hall sensor signals are detected during an adjustment for a period of 350 ms. If the blockage is recognized in the closing direction, the sliding roof motor is first stopped and then actuated in the opposite direction. If the blockage is recognized in the opening direction, the sliding roof motor is stopped and no longer actuated.
Additional function requirements for opening/closing sliding roof
- Circuit 15R ON or run-on time active (up to t = 5 min after circuit 15R OFF, with front doors not yet open)
The electronic ignition lock control unit sends the status of circuit 15 via interior CAN to the sliding roof control module. The front door control units transmit the status of the front doors (open or closed) to the sliding sunroof control module via interior CAN.
Open/close sliding roof
The sliding roof can be opened and closed manually or automatically.
The sliding roof is opened or closed manually for the time the request is active by actuating the roof system switch to the first catch.
The sliding roof is fully opened or closed automatically by actuating the roof system switch beyond the first catch.
Automatic adjustment is aborted if the roof system switch is actuated again.
The overhead control unit transmits the status of the roof system switch to the sliding roof control module via the interior CAN.
For vehicles as of model year 2018 with code 360 (HERMES UMTS) or code 362 (HERMES LTE), web-based operation of the sliding sunroof via a browser is possible. Smartphones, tablets or PCs can be used for this, for example. In addition, the status of the sliding sunroof can be called up. At the vehicle side, the telematics services are realized by the HERMES control unit via a cellular telephone system connection to the Service Center.
The HERMES control unit transmits the request to open or close the sliding sunroof via the diagnostics CAN to the electronic ignition lock control unit. The electronic ignition lock control unit checks the request and transmits it to the sliding sunroof control module via the interior CAN.
The sliding roof control module actuates the sliding roof motor according to the selected operating direction.
When the sliding sunroof is denormalized, it can only be actuated in steps of 0.5 s each.
Recognition of switch signals:
The actuation of the roof system switch is only clearly detected after 40 ± 10 ms. The max. actuation time is 20 s. After 60 s, the system considers the roof system switched to be jammed. 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.
Additional function requirements for automatic reversing function
- Active actuation of sliding roof
- Sliding roof NORMALIZED
- Valid reference data present for automatic reversing function
Automatic reserving function
The automatic reversing function is based on a comparison between the current power consumption of the sliding roof motor and the power consumption recorded during a teach-in run or adaptation. If this difference exceeds a certain limit value during a closing operation, this is detected as a pinching of the overhead control panel control unit.
Teach-in run:
This involves operating all of the closing procedures of the sliding sunroof automatically in the normalized condition. The sliding sunroof control module adapts a change in the power consumption of the sliding sunroof motor resulting from increased sluggishness (e.g. dirt in the mechanical system).
If a blockage is detected during an opening procedure, the sliding roof is stopped. During a closing procedure, the sliding roof is stopped and then reversed (moved in the opposite direction). Special case, manual closing:
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 attempt deactivates the automatic reversing function.
Additional function requirements for rain closing
- Circuit 15R OFF or vehicle locked
- Sliding roof open in slide position
- Sliding roof NORMALIZED
The circuit 15 status and the central locking status are sent by the electronic ignition lock control unit over the interior CAN to the sliding roof control module.
Rain closing
The sliding roof is moved to the tilt position when it starts to rain. 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 sliding sunroof control module via the rain and light sensor LIN, front SAM control unit and interior CAN. The sliding roof control module then actuates the sliding roof motor. The sliding roof is moved to the tilt position. Monitoring is then no longer performed.
The adjustment to tilt position also takes place if the run-on time (6 h) expires or the voltage or temperature is no longer within the operating range of the rain and light sensor with additional functions.
Model 213
up to model year 2021
with code 414 (Electric sunroof, glass version)
with code 882 (Interior protection and tow-away protection)
Alarm triggering by the interior protection is suppressed during adjustment to prevent the anti-theft alarm system (ATA [EDW]) from being triggered unintentionally.
| Electrical function schematic for sliding roof | PE77.20-P-2054-97DBA | ||
| Overview of system components for electric power sliding roof | GF77.20-P-9989FG |