Electric Power Sliding Roof, Function - GF77.20-P-0007GN
MODEL 166
as of model year 2016
with CODE 414 (Sliding sunroof)
Function requirements, general
- No overvoltage or undervoltage
- Consumer shutoff not active
- Transport mode not activated
Detailed information on the operating state of the transport mode is given in the separate function description for energy management.
Sliding roof, general
The sliding roof function allows the sliding roof to be opened and closed. The tilting/sliding roof is operated with the sliding roof switch in the overhead control panel control unit. The sliding roof is a combined sliding/tilting roof.
Overheating protection:
The sliding roof system motor is not designed for continuous operation. An integrated thermal protection circuit protects the sliding roof motor from overload.
The temperature of the sliding roof motor is extrapolated based on the operating time. 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 can also be operated using the convenience features, which allow the sliding roof to be opened and closed centrally together with the side windows from one control point.
Detailed information on this is available in the separate function description for theft protection and locking in the convenience feature function.
PRF-SAFF®:
The sliding roof is closed automatically in certain hazardous situations. Detailed information on this can be found in the separate "PRF-SAFF® function" function description.
The sliding roof function comprises the following partial functions:
- Function sequence for normalization
- Function sequence for position monitoring and blockage detection
- Function sequence for opening/closing sliding roof
- Function sequence for automatic reserving function
- Function sequence for rain closing
Additional function requirements for normalizing
- Sliding roof denormalized
- Circuit 15R ON or run-on time active (up to t = 5 minutes after circuit 15R OFF, with front door closed)
The electronic ignition lock control unit sends the status of circuit 15 via interior CAN to the sliding roof control module.
The right front door control unit sends the status of the right front door over the interior CAN to the sliding roof control module.
Function sequence for normalization
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 roof via the sliding roof switch until the mechanical end stop is reached. Then press the sliding roof switch again for at least t = 1 second. 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 two Hall sensors fails for 10 signal edges
- If both Hall sensors fail to supply signals for longer than t = 320 ms when reversing
- For sliding roof actuation with undervoltage
The position of the sliding roof cannot be determined in the denormalized condition. The function is then restricted to manual opening and closed in increments of t = 0.5 s.
Additional function requirements for position monitoring and blockage detection
- Active actuation of sliding roof
Function sequence for position monitoring and blockage detection
The sliding roof control module monitors the position of the sliding roof by evaluating the Hall sensor signals.
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 zero position is defined as the position: sliding roof open in tilt position. The zero position is set by normalization. Blockage is detected if no signals from the Hall sensors are detected for a period of t = 350 ms during adjustment. 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 minutes after circuit 15R OFF, with a front door 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 left front door control unit sends the status of the left front door over the interior CAN to the sliding roof control module.
The right front door control unit sends the status of the right front door over the interior CAN to the sliding roof control module.
Function sequence for opening/closing sliding roof
The sliding roof can be opened and closed manually or automatically.
The sliding roof is opened or closed manually for the duration of the pending request by actuating the sliding roof switch to the first detent.
The sliding roof is fully opened or closed automatically by actuating the sliding roof switch beyond the first detent.
Automatic adjustment is aborted if the roof switch is actuated again. The automatic reversing function is active during closing.
The overhead control panel control unit reads in the status of the sliding roof switch directly and sends this over the roof LIN, front SAM control unit and the interior CAN to the sliding roof control module. The sliding roof control module actuates the sliding roof motor according to the selected operating direction.
When the sliding roof is denormalized, it can only be actuated in steps of t = 0.5 s each.
Detection of switch signals:
Actuation of the sliding roof switch is clearly recognized only after t = 40 ± 10 ms. The maximum actuation time is approx. t = 20 s. A "stuck" sliding roof switch is recognized after approx. t = 60 s. A new actuation (triggered through the sliding roof switch) can only be performed again after detecting that the sliding roof switch is in the rest position.
Additional function requirements for automatic reversing function
- Sliding roof NORMALIZED
- Valid reference data present for automatic reversing function
Function sequence for 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:
During a learn-in run all of the sliding roof closing procedures are accomplished in the normalized condition. The sliding roof control module adapts a change in the power consumption of the sliding roof 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 sliding roof system switch is actuated again in the closing direction within t = 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
The electronic ignition lock control unit transmits the status of circuit 15 and the central locking status to the sliding roof control module over the interior CAN.
Function sequence for 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, evaluates them and sends the "Rain closing" request over the roof-LIN, front SAM control unit and the interior CAN to the sliding roof control module. 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.
Rain closing is performed even if the run-on time (t = 6 h) has expired or the voltage or temperature is no longer within the range of the rain sensor.
MODEL 166 as of model year 2016 with CODE 414 (Sliding sunroof)
with CODE 882 (Interior motion sensor)
During rain closing, an alarm actuation is suppressed by the interior protection to prevent an unintentional actuation of the anti-theft alarm system (ATA).
| Electrical function schematic for sliding roof | PE77.20-P-2054-97NBA | ||
| Overview of system components for electric power sliding roof | GF77.20-P-9989GN |