Sunroof / Moonroof: Description and Operation

61 08 03 (030)
Sliding/tilt sunroof
E60





Introduction
The electric sliding/tilt sunroof is a glass roof (option 403).
As usual, the sliding/tilt sunroof has a dedicated control unit (SHD control unit) of its own.
The Car Access System (CAS) controls convenience operation of the sliding/tilt sunroof (convenience opening/convenience closing)

Brief description of components
The components that supply input signals for the sliding/tilt sunroof are as follows:

- Sliding/tilt sunroof switch
The sliding/tilt sunroof switch is set in the operating unit in the headliner.
The sliding/tilt sunroof switch can be moved in three directions (press forward, press to rear, press up).
- Hall sensors in the motor for the sliding/tilt sunroof
There are two Hall sensors integrated into the motor for the sliding/tilt sunroof. They enable the control unit for the sliding/tilt sunroof (SHD control unit) to identify the position of the sliding/tilt sunroof. The speed of closing is used, moreover, to calculate the closing force.
The control units involved in the functions of the sliding/tilt sunroof are as follows:
- Control unit for the sliding/tilt sunroof (SHD control unit)
The SHD control unit forms a unit in combination with the motor. The SHD control unit controls all the electrical functions of the sliding/tilt sunroof.
The SHD control unit also controls dimming of the locating light (terminal 58g) in the sliding/tilt sunroof switch.
- Car Access System CAS
The Car Access System CAS controls convenience opening and convenience closing of the sliding/tilt sunroof. The CAS forwards the request (from the remote control, for example) to the SHD control unit via the K-CAN.
- Light Module LM
The light module sends the SHD control unit the request to switch on the locating light via the K-CAN (terminal 58g).
The actuators actuated for the purposes of the functions of the sliding/tilt sunroof are as follows:
- Motor for sliding/tilt sunroof
The drive is a direct-current motor with reduction gearing. The motor forms a unit in combination with the SHD control unit.

System functions
The sliding/tilt sunroof comprises the following functions:

- Opening and closing
- Convenience opening and convenience closing
- Emergency close
- Anti-trap function (limits closing force)
- Safety functions
- Check-control messages



Opening and closing
The functions for opening and closing are as follows:
- Manual closing or opening
Press the sliding/tilt sunroof switch forward to the first pressure point (to close) or toward the rear (to open).
The sliding/tilt sunroof continues to move in the appropriate direction for as long as the sliding/tilt sunroof switch is pressed.
- Automatic closing or opening
Press the sliding/tilt sunroof switch forward past the first pressure point to the mechanical stop (to close) or toward the rear (to open). The sliding/tilt sunroof automatically moves in the corresponding direction to the limit position. Pressing the sliding/tilt sunroof switch for a second time stops the automatic movement.
- Tilt
Press the sliding/tilt sunroof switch up to the mechanical stop. The sliding/tilt sunroof lifts to the fully tilted angle, irrespective of the original position. There is no provision for tilting the sunroof manually.



Convenience opening and convenience closing
The sliding/tilt sunroof opens and closes along with the electrically operated windows. The controls that can be used for this purpose are as follows:
- Press the button on the remote control (radio remote control key) to the position for unlocking or locking/deadlocking and hold it in this position until the sliding/tilt sunroof reaches the desired position.
- Use the mechanical key to turn the lock in the driver's door to the position for unlocking or locking and hold it in this position until the sliding/tilt sunroof reaches the desired position.
The sequence for convenience opening is as follows:
- both front power windows
- after a delay, both rear power windows
- after a delay, the sliding/tilt sunroof
The sequence for convenience closing is as follows:
- both rear power windows
- after a delay, both front power windows
- after a delay, the sliding/tilt sunroof
The convenience opening/convenience closing function is stopped if the command is cancelled.



Emergency close
Emergency closing is a function for deliberate closure of the sliding/tilt sunroof without anti-trap function (limitation of closing force). It can be necessary to resort to this function if someone attempts to reach into the interior of the car or if mechanical difficulty is experienced in closing the sliding/tilt sunroof.
Emergency closing can be activated when the car is stopped or travelling at a speed up to 16 km/h.
Emergency closing is a two-phase operation:
Phase 1:
Press the sliding/tilt sunroof switch (in the "close" direction") to the mechanical stop. A short response time elapses before the sliding/tilt sunroof closes at maximum speed.
If the sliding/tilt sunroof switch is released, the sliding/tilt sunroof automatically closes (with anti-trap function). Closure is interrupted if the anti-trap function sensor trips. The direction of travel reverse and the sliding/tilt sunroof opens by approximately 20 mm.
Phase 2:
If the sliding/tilt sunroof switch is released in phase 1 and the sliding/tilt sunroof switch is then pressed again past the pressure point within approximately 1.5 seconds, the sliding/tilt sunroof closes without anti-trap function. In this mode, the sliding/tilt sunroof closes with maximum force and maximum speed. If an obstruction is encountered the motor continues to receive power until the thermal switch trips to prevent overheating.
The sliding/tilt sunroof can be opened at any time, even if the thermal switch has tripped.



Anti-trap function (limitation of closing force)

Warning! Note initialization
The sliding/tilt sunroof has to be initialized in order for the anti-trap function to function correctly. The sliding/tilt sunroof has to be initialized by service staff.



Anti-trap function is active over the entire range of movement in the closing direction. Anti-trap function does not in principle prevent trapping; instead, it limits the maximum permissible force applied to the trapped object (limitation of closing force).
Two Hall sensors are integrated into the motor in order to prevent impermissibly high closing forces. The speed of closure can be measured on the basis of the signals from these two Hall sensors. The closing force is calculated from the speed of closure.
Irrespective of temperature and the voltage in the on-board network, the sliding/tilt sunroof opens approximately 20 mm if the anti-trap function is tripped.
The mechanical forces involved change with ambient temperature and as a result of ageing processes. Consequently, the closing force (mapping) is relearnt each time the sunroof closes, so that the anti-trap function can adjust accordingly.
In each subsequent closure, the closing force currently needed is calculated and compared with the characteristic map. If the difference between these two force values is above the preset tripping threshold, the sliding/tilt sunroof immediately opens. The anti-trap function can be deactivated by the emergency close function (see Emergency close).
Automatic closing is not possible if anti-trap function fails (on account of defective Hall sensor, for example).
Interference affecting the closing force can occur when the car is in use. Interference of this nature can take the form of severe vibrations, slipstream (sliding/tilt sunroof in tilted position) and stiff action on account of coldness or a build-up of foreign matter. Interference of this nature is detected by the system. Unexpected difficulties caused by build-up of foreign matter, ice or damage can be overcome by the emergency close function.



Safety functions
- Maximum motor ON time
If the sliding/tilt sunroof fails to reach a limit position, the motor is switched off after 15 seconds.
- Overheating protection
The heat rise in the motor is computed on a model basis in the SHD control unit. The temperature signals available are the ambient temperature and the interior temperature (via K-CAN). The board of the SHD control unit also incorporates an electronic thermometer (transistor).
- Emergency operation
In emergency operation, the sliding/tilt sunroof can be operated for only 750 milliseconds per step. Emergency operation is possible under the following circumstances:
- Encoding of the SHD control unit incorrect
- Signal of a Hall sensor implausible
- Initialization incomplete



Check-control messages
Two check-control messages can be issued for the sliding/tilt sunroof. The check-control messages are indicated by the variable-function indicator light in the instrument cluster.






Note: Mechanical emergency operation is possible
The sliding/tilt sunroof can be operated manually in the event of an electrical malfunction. Open the holder for the interior lights. Fit the Allen key from the toolkit into the opening in the drive of the sliding/tilt sunroof and turn the key to move the sunroof in the desired direction.

Notes for service staff
Service staff should note the following points:

- General information:
- Diagnosis: ---
- Encoding/programming: ---
- Car & Key Memory: ---
Subject to alteration due to misprints, errors and technical modifications.