Sunroof / Moonroof: Description and Operation
Slide/Tilt Sunroof
Slide/tilt sunroof
The slide/tilt sunroof is available as an optional extra. It is an advanced-design sunroof known as a contour sunroof. The slide/tilt sunroof consists of a glass panel that can be opened or raised. A sliding headliner can be retracted to expose the glass panel, allowing light into the passenger compartment.
The slide/tilt sunroof runs on internal guide rails. The components of the slide/tilt sunroof (glass panel and sliding headliner) are moved by 2 drive motors:
1. Glass panel drive motor
2. Sliding visor motor
Two hall effect sensors are incorporated in each of the mutually identical drive units. The hall effect sensors are located on the drive units' shafts at a mutual deviation angle of 90 degrees.
The drive units are operated using a new operating logic by means of the sunroof switch on the roof control panel (FZD). The glass panel and the sliding headliner can be operated together or separately using the sunroof switch. The components move in the same direction as the direction in which the button is moved.
The following table details the features of the slide/tilt sunrooves on the various models:
When the slide/tilt sunroof is fully closed the noise level in the passenger compartment is comparable to that of a vehicle without a sunroof.
A wind deflector is provided to ensure that noise levels remain agreeable when the slide/tilt sunroof is completely open. The wind deflector has a positive effect on noise levels in the passenger compartment.
A closing force limited has been provided to prevent potential injuries.
Several control units are involved in the functions of the slide/tilt sunroof.
The user-control concept for the slide/tilt sunroof is as follows:
The following illustration shows the size of the F01 slide/tilt sunroof compared to conventional slide/tilt sunrooves.
Brief component description
The following components of the slide/tilt sunroof are described:
- Roof function centre (FZD)
- Car access system (CAS)
- Footwell module (FRM)
- Slide/tilt sunroof switch
- Slide/tilt sunroof drive motors
Roof function centre (FZD)
The slide/tilt sunroof is controlled and monitored from the roof function centre (FZD). The roof function centre (FZD) receives signals from other control units for the various functions of the slide/tilt sunroof:
- The Car Access System (CAS) supplies the enabling signal allowing operation of the slide/tilt sunroof
- The footwell module (FRM) supplies signals from the door contacts
- The Junction Box Electronics (JBE) module provides access to Terminal 30B through the roof function centre (FZD).
The roof function centre (FZD) responds to commands requesting operation of the slide/tilt sunroof by activating the two integral relays. The relays supply the appropriate drive units with voltage.
The roof function centre (FZD) monitors the relay contacts to ensure correct operation (glass panel and sliding headliner). Two hall effect sensors are integrated within each of the drive units. The pulses from the hall effect sensors are employed by the roof function centre (FZD) as the basis for calculating travel speeds and operating paths and identifying the direction of rotation. The travel distance required for opening and closing is stored in the roof function centre. While traversing this travel distance the drive units generate a specific number of pulses.
Consequently, the roof function centre (FZD) is able to detect the position of the glass panel and sliding headliner. The roof function centre (FZD) calculates closing force based on the closing speed. The required mechanical force varies as a function of ambient temperature and as a result of ageing processes. For this reason the closing force required and the parameters for the closing force limiter are adapted for the closing actions in defined distances.
The following slide/tilt sunroof functions integrated in the roof function centre (FZD):
- Read in command request
- Controlling and monitoring glass panel drive motor and sliding headliner drive motor
- Closing force limiter
- Locking protection
- Panic mode
- Load cutoff during starting up (automatic engine start-stop function)
- Locator lighting (terminal 58g) in the slide/tilt sunroof switch
- Initialization.
Car access system (CAS)
The Car Access System (CAS) supplies the enable signal allowing operation of the slide/tilt sunroof. The Car Access System (CAS) transmits the status "Terminal 50 on" via K-CAN2. The roof function centre (FZD) prevents activation of the drive units and also suspends any ongoing travel motion while the engine is being started. This increases the amount of voltage available to the starter motor.
Footwell module (FRM)
The footwell module (FRM) supplies the Car Access System (CAS) with the status information on the door switches for enabling the slide/tilt sunroof.
This status information is needed for the "convenient opening" and "convenient closing" functions.
The footwell module (FRM) also supplies the roof function centre (FZD) with information on the status "Terminal 58g on". The roof function centre (FZD) operates the LED in the sunroof switch.
Slide/tilt sunroof switch
Using the sunroof switch in the roof function centre (FZD), the slide/tilt sunroof can be opened, closed or raised. When the sunroof switch is operated, a corresponding signal is sent to the roof function centre (FZD).
The sunroof switch is integrated in the roof function centre (FZD) and can be moved in 3 directions:
The sunroof switch can be set to 2 self-locating positions in opening and closing directions. With the sunroof switch in the first self-locating position the sunroof moves only as long as the switch is held. Applying additional pressure to engage the second detent activates the toll function (automatic function). The tollbooth function initiates opening/closing of the sunroof that continues without the sunroof switch having to be continuously held. In addition to the toll and detent-engagement functions, the switch also features a double-click function for operation in the "open" and "close" directions. The double-click function is activated by quickly pressing the switch into the detent-engagement position twice in rapid succession. In that way, automatic opening or closing of the glass panel and sliding headliner can be initiated from any position. When the sunroof is in motion it can be stopped by pressing the switch again.
When the exterior lights is switched on, the footwell module (FRM) transmits this information on K-CAN2. The roof function centre (FZD) receives this information and adopts the selected setting for the instrument lighting. The LED in the sunroof switch is controlled by means of a pulse-width modulation signal from the roof function centre (FZD). This ensures that the brightness level of the light-emitting diode remains constant even when the electrical vehicle voltage fluctuates.
Slide/tilt sunroof drive motors
The glass panel drive motor is mounted on the sunroof frame below the roof function centre (FZD).
The sliding headliner is driven by a separate drive motor. The sliding headliner drive motor is mounted from below on the sunroof frame close to the centre of the roof.
The slide/tilt sunroof drive motors each consist of an electric motor and a reduction gear.
When the roof function centre (FZD) receives an instruction to operate the slide/tilt sunroof, it operates the relevant drive motor. The relay integrated within the roof function centre (FZD) supplies the drive with voltage. There 2 Hall sensors integrated in the drive. The hall effect sensors detect the engine revolutions and the direction of rotation.
The hall effect sensor signals are transmitted to the roof function centre (FZD). The Hall-effect sensors enable the roof function centre (FZD) to detect the position of the sunroof. The roof function centre (FZD) calculates the closing force based on the closing parameters.
System overview
System functions
User-control commands for the slide/tilt sunroof can be communicated by means of the following controls:
- Slide/tilt sunroof switch
- ID transmitter
- Outside handle with optional equipment Comfort Access
- Mechanical key in driver's door lock.
The following system functions are described:
- Opening sliding headliner
- Opening glass panel
- Opening sliding headliner and glass panel
- Raising glass panel and setting sliding headliner to ventilation position
- Raising glass panel
- Closing glass panel
- Closing sliding headliner
- Closing glass panel and sliding headliner
- Convenient opening
- Convenient closing
- Wind deflector
- Safety functions.
Opening sliding headliner
Starting situation: glass panel and sliding headliner closed.
Press open.
- Signal from sunroof switch to roof function centre (FZD)
- Roof function centre (FZD) operates the sliding headliner drive motor as long as sunroof switch is held
- Sliding headliner drive motor opens the sliding headliner
- Glass panel remains closed
Press to detent-engagement position to open (toll function).
- Signal from sunroof switch to roof function centre (FZD)
- The roof function centre (FZD) activates the sliding visor motor
- Sliding headliner drive motor fully opens the sliding headliner
- Glass panel remains closed
Opening glass panel
Starting situation: sliding headliner open.
Press open.
- Signal from sunroof switch to roof function centre (FZD)
- Roof function centre (FZD) operates glass panel drive motor as long as sunroof switch is held
- Glass panel drive motor opens glass panel
Press to detent-engagement position to open (toll function).
- Signal from sunroof switch to roof function centre (FZD)
- Roof function centre (FZD) operates glass panel drive motor
- Glass panel drive motor fully opens glass panel
Opening sliding headliner and glass panel
Starting situation: glass panel and sliding headliner closed.
Press twice to open (double-click function).
- Signal from sunroof switch to roof function centre (FZD)
- The roof function centre (FZD) starts by activating the sliding visor motor
- Sliding headliner drive motor fully opens the sliding headliner
- Roof function centre (FZD) operates glass panel drive motor after time delay
- Glass panel drive motor fully opens glass panel
Raising glass panel and setting sliding headliner to ventilation position
Starting situation: glass panel and sliding headliner closed.
Press once to raise.
- Signal from sunroof switch to roof function centre (FZD)
- Roof function centre (FZD) operates glass panel drive motor and sliding headliner drive motor
- Glass panel drive motor fully raises glass panel
- Sliding headliner motor moves sliding headliner to ventilation position
Raising glass panel
Starting situation: glass panel closed and sliding headliner open.
Press once to raise.
- Signal from switch for panorama glass roof to roof function centre (FZD)
- Roof function centre (FZD) operates glass panel drive motor
- Glass panel drive motor fully raises glass panel
Closing glass panel
Starting situation: glass panel and sliding headliner open.
Press close.
- Signal from sunroof switch to roof function centre (FZD)
- Roof function centre (FZD) operates glass panel drive motor as long as sunroof switch is held
- Glass panel drive motor closes glass panel
Press to detent-engagement position one time to close (toll function).
- Signal from sunroof switch to roof function centre (FZD)
- Roof function centre (FZD) operates glass panel drive motor
- Glass panel drive motor fully closes glass panel
Closing sliding headliner
Starting situation: glass panel closed.
Press close.
- Signal from sunroof switch to roof function centre (FZD)
- Roof function centre (FZD) operates sliding headliner drive motor as long as sunroof switch is held
- Sliding headliner drive motor closes sliding headliner
Press to detent-engagement position one time to close (toll function).
- Signal from sunroof switch to roof function centre (FZD)
- The roof function centre (FZD) activates the sliding visor motor
- Sliding headliner drive motor fully closes sliding headliner
Closing glass panel and sliding headliner
Starting situation: glass panel raised and sliding headliner in ventilation position.
Press close.
- Signal from sunroof switch to roof function centre (FZD)
- Roof function centre (FZD) operates glass panel drive motor followed by sliding headliner drive motor as long as sunroof switch is held
- Glass panel drive motor closes glass panel
- Sliding headliner drive motor closes sliding headliner
Press to detent-engagement position one time to close (toll function).
- Signal from sunroof switch to roof function centre (FZD)
- Roof function centre (FZD) operates glass panel drive motor and sliding headliner drive motor
- Glass panel drive motor fully closes glass panel
- Sliding headliner drive motor fully closes sliding headliner
Starting situation: glass panel and sliding headliner open.
Press twice to close (double-click function).
- Signal from sunroof switch to roof function centre (FZD)
- Roof function centre (FZD) first operates glass panel drive motor
- Glass panel drive motor fully closes glass panel
- Roof function centre (FZD) operates sliding headliner drive motor when remaining glass panel aperture reaches a certain point
- Sliding headliner drive motor fully closes sliding headliner
Convenient opening
Convenient opening using the sensitive surface on the outside handle provided with the optional equipment "Comfort Access" feature is not possible.
The slide/tilt sunroof can be opened as follows:
- Extended pressure on the "unlock" button of the ID transmitter
- Extended holding of the mechanical key in the "open" direction while it is inserted in the driver's door lock.
The convenient opening starts with a delay after the power window regulator motion.
Convenient closing
Convenient closing using the sensitive surface on the outside handle provided with the optional equipment "Comfort Access" feature is not possible.
The slide/tilt sunroof can be closed as follows:
- Extended pressure on the locking button of the ID transmitter
- Extended holding of the mechanical key in the "lock" direction while it is inserted in the driver's door lock
- Extended hand contact with the sensitive surface on the outer door handle (optional equipment Comfort Access)
Extended hand contact with the sensitive surface on vehicles with the optional equipment Comfort Access is required to initiate the "convenient" process. Only after this extended period will the roof function centre (FZD) execute the convenient closing function. Removing pressure from the sensitive surface interrupts the convenient closing function.
The convenient closing starts with a delay after the power window regulator motion.
Wind deflector
The wind deflector is raised or lowered when the glass panel is opened or closed.
On the F01, F02 and F04 a wind deflector is used which can also be raised to different heights depending on the speed of the vehicle. The sliding headliner drive motor is operated by the roof function centre (FZD) to adjust the speed-dependent wind deflector.
Safety functions
- Maximum motor running time
When the motor continues to run in a single direction for a specific period (roughly 15 seconds), the roof function centre (FZD) deactivates the drive unit.
- Overheating protection
Operation of the drive unit's overheating protection is governed by calculations carried out in the roof function centre (FZD). This process is supported by a temperature sensor mounted on the roof function centre's printed circuit board, where it registers the ambient temperature. The roof function centre (FZD) calculates current temperature based on the drive units' operating period. Once the temperature in a drive unit reaches a specified threshold the roof function centre (FZD) deactivates it. The warm-up and cooling-down periods are stored in a temperature model in the roof function centre (FZD).
The current temperature is stored before the roof function centre (FZD) reverts to its rest state. When the vehicle is restarted the drive-unit temperature is synchronized with the ambient temperature. Closing the slide/tilt sunroof is still possible even if the overheat cut-out is active.
- Locking protection
Seizure is recognized when no pulses from the hall effect sensors are received for longer than 500 milliseconds while travel motion is being executed. The roof function centre (FZD) deactivates the voltage supply to the drive unit where seizure occurs.
- Closing force limiter
Both the glass panel and the sliding headliner are equipped with closing force limiters. Activation of the closing force limiter is based on electrical power consumption and the signals from the hall effect sensor over a given period of time. The roof function centre (FZD) responds to conditions in which fingers could potentially become trapped by stopping the corresponding drive unit and then reversing its motion. That opens the glass panel or sliding headliner again (by about 20 centimeters), thereby releasing the obstruction.
- Panic mode
The "panic mode" is only available provided that a valid enable signal has been received from the Car Access System (CAS).
In panic mode the glass panel is closed with maximum power. Panic mode is initiated as follows using the sunroof switch:
1. Press "close" to beyond the detent-engagement point and hold it in place
In the case of a trap situation the glass roof reverses by approx. 1 centimeter.
2. Release slide/tilt sunroof switch
3. Press "Close" and hold it in place.
Releasing the switch and then pressing it again is necessary because the reduced closing force limiter is still active the first time the switch is pressed (Emergency mode). Pressing the switch past "Close" a second time within a short space of time closes the glass panel with maximum power. The panic mode is available for activation at driving speed of up to 16 kilometers per hour. The panic mode can be activated from both the "raised" and the "open" positions.
- Load cutoff
Operation of the slide/tilt sunroof is stopped or prevented while the engine is being started. The Car Access System (CAS) transmits the status "Terminal 50 on". The load cutoff minimizes loads imposed on the battery during starting. Once the engine has been started, the slide/tilt sunroof can be operated again.
Notes for Service department
Initialization
Initialization of the slide/tilt sunroof involves the following processes, which are required for complete functionality of the slide/tilt sunroof:
- Normalization
- Teach-in of closing force limiter.
Normalization
Calibration determines the mechanical end position at the glass panel "raised" position end stop and the sliding headliner "open" position end stop. Those positions are stored and then used to calculate the remaining slide/tilt sunroof positions. The distances that the sunroof must travel to reach the various positions are known to roof function centre (FZD). Travel is recognized based on the pulses generated by the hall effect sensors while the drive unit motors rotate. This makes it possible to calculate one end position based on information about the opposite end position.
Teach-in of closing force limiter
Teach-in of the closing force limiter records and saves the required closing forces. Only complete learning of closing force limitation ensures total functionality of the slide/tilt sunroof. The learning process can be carried out using the sunroof switch or the diagnosis system.
- Using the sunroof switch
For the teach-in of the closing force limiter the ambient temperature must be approx. 23 degrees Celsius and the battery voltage must exceed 11.5 volts. The vehicle must also be at a standstill. If necessary, the engine (depending on model and country) must be started.
Press the sunroof switch to "Raise" and keep it pressed throughout the initialization process.
- Glass panel is raised and sliding headliner moves to ventilation position.
- After approx. 15 seconds the sliding headliner is fully opened.
- After roughly 5 seconds the glass panel is fully opened and then closed again.
- Then the sliding headliner is closed again.
The initialization procedure must be repeated in its entirety should it be interrupted before completion. The initialization process lasts approximately 50 seconds.
Erasure of initialization
The initialization data can be deleted under the following conditions if necessary:
- Interruption of the electrical supply voltage during initialization
- Malfunction detected at hall effect sensors
- Implausible position
- Specific commands of diagnosis
- Revised vehicle code
- Coding data faulty.
We can assume no liability for printing errors or inaccuracies in this document and reserve the right to introduce technical modifications at any time.