Slide/tilt sunroof R56

Slide/tilt sunroof

The slide/tilt sunroof consists of 2 glass sunroofs. The front glass sunroof functions in the same way as a slide/tilt sunroof; the rear glass sunroof is a glass tilt roof.
The slide/tilt sunroof is activated by a separate control unit.

The slide/tilt sunroof is an optional extra (option 403).

Brief description of components

The following components are described for the slide/tilt sunroof:

Slide/tilt sunroof switch

The slide/tilt sunroof switch is located in the roof operating unit.

The slide/tilt sunroof switch does not lock in position. The slide/tilt sunroof switch can be moved in 2 directions:

• press forwards (slide/tilt sunroof ”close”)
  
• press backwards (slide/tilt sunroof ”lift” and ”open”)
  

If the switch is released, the slide/tilt sunroof remains in its current position (if the switch is not pressed beyond the resistance point).

Towards ”Open” and ”Close”, there is a resistance point. With operation beyond the resistance point, the slide/tilt sunroof is automatically opened or closed, even if the slide/tilt sunroof switch is released. If the slide/tilt sunroof switch is operated again, the slide/tilt sunroof remains in its current position.

Note: The ”Open” or ”Close” operation of the slide/tilt sunroof is interrupted when the ”Lift” position is reached.

If the ”Lift” position during automatic opening or closing of the slide/tilt sunroof is reached, the ”Open” or ”Close” operation is interrupted. To continue the operation, the slide/tilt sunroof switch must be operated once again.

SHD control unit

The SHD control unit controls all the electrical functions of the slide/tilt sunroof.
The drive forms a unit together with the SHD control unit.
The SHD control unit is supplied with voltage via terminal 30g.

Slide/tilt sunroof drive

The drive for the slide/tilt sunroof consists of a direct current motor with reduction gears. The DC motor activates the two glass sunroofs.
The drive forms a unit with the SHD control unit.
The slide/tilt sunroof drive is supplied with voltage via terminal 30g.

Hall sensors in the slide/tilt sunroof drive

Two Hall sensors are integrated in the electric motor of the slide/tilt sunroof. The Hall sensors pick up the motor revolutions. The signals are forwarded to the SHD control unit. The signals enable the control unit to detect the position of the two glass sunroofs. In addition, the closing speed of the electric motor is used to calculate the closing power for both glass sunroofs.

CAS: Car Access System

The CAS controls convenience opening or convenience closing of the slide/tilt sunroof. The CAS forwards the request (e.g. from the remote control) on the body CAN to the SHD control unit.

CA: Comfort Access

With optional extra 322 ”Comfort Access”, convenience closing of the slide/tilt sunroof is possible without active use of the identification sensor.
(The remote control is the key for the central-locking system. The identification sensor is the key for the central-locking system on vehicles with comfort access.)

If the outer door handle button on the driver's side or outer door handle button on the passenger's side is touched to lock at the outer door handle (approx. 3 seconds), convenience closing starts. The status of the button is sent across a direct cable to the CA control unit. The CA control unit sends the status across the K bus to the CAS control unit.

Convenience opening using the button is not possible.

The CAS control unit is the master control unit for functions run by Comfort Access. On vehicles with Comfort Access, a CA control unit is fitted. The CA control unit is connected via the K bus with the CAS control unit.

Roof operating unit

The slide/tilt sunroof switch is integrated in the roof operating unit. The symbol for the slide/tilt sunroof above the slide/tilt sunroof switch is illuminated. The footwell module (FRM) controls the lighting.

Wind deflector

On opening the slide/tilt sunroof, the wind deflector with a net sets up automatically after approx. 10 cm of the opening path. With the slide/tilt sunroof opened, the raised wind deflector reduces noise in the vehicle interior.

System functions

The following system functions are described for the slide/tilt sunroof:

• Opening and closing
  
• Convenience opening and/or convenience closing
  
• Emergency close
  
• Anti-trapping protection (closing power limitation)
  
• Safety functions
  
• Check Control message
  
  

Opening and closing

There are the following functions for opening and closing:

• Opening and closing
  
  • Manual closing or opening
    Press back the slide/tilt sunroof switch up to the first resistance point (for opening) or press forward (for closing).
    The glass slide/tilt sunroof moves also long as the switch is kept pressed.
    On opening, the slide/tilt sunroof (both glass sunroofs) is raised automatically. As the process continues, the rear glass sunroof closes. Subsequently, the front glass sunroof is now also raised at the front anchorage point. This enables the front glass sunroof to be shifted above the rear glass sunroof.
    

• • Automatic closing or opening
    Press the slide/tilt sunroof switch forwards beyond the first resistance point up to the mechanical limit position (for closing) or press towards the rear (for opening). If the slide/tilt sunroof switch is pressed again, the automatic movement is halted.
    
    

Note: The ”Open” or ”Close” operation of the slide/tilt sunroof is interrupted when the ”Lift” position is reached.

If the ”Lift” position during automatic opening or closing of the slide/tilt sunroof is reached, the ”Open” or ”Close” operation is interrupted. To continue the operation, the slide/tilt sunroof switch must be pressed again - beyond the first resistance point.

Note! No automatic closing is possible on failure of the anti-trapping mechanism.

In the event of failure of the anti-trapping mechanism (e.g. defective Hall sensor), no automatic closing is possible. Closing is only possible with the mechanical emergency actuating unit.
Possible defect data is stored in the SHD control unit.

Convenience opening and/or convenience closing

Note: Convenience opening only possible up to end position ”lift”.

The ”convenience opening” function is only run by the SHD control unit up to the end position ”lift”.

The following operating points are possible:

• Button on the remote control (radio-control key)
  
  • Convenience opening:
    Press and hold down the button on the remote control at ”Unlock” until the slide/tilt sunroof has reached the desired position.
    
  • Convenience closing:
    Function not possible!
    
• Door lock on driver's door
  
  • Convenience opening:
    use the mechanical key to hold the door lock on the driver's door at ”Unlock” until the slide/tilt sunroof has reached the desired position.
    
  • Convenience closing:
    Use the mechanical key to hold the door lock on the driver's door at ”Lock / Double-lock” until the slide/tilt sunroof has reached the desired position.
    
• Button on outer door handle (driver) or button on outer door handle (passenger)
  If the vehicle is equipped with optional extra 322 ”comfort access” (CA), convenience closing can be started using the button in the outer door handle on the driver's side or passenger's side.
  
  • Convenience opening:
    function not possible!
    
  • Convenience closing
    Hold the button on the outer door handle on the driver or passenger side for ”Lock/Double-lock” until the slide/tilt sunroof has reached the desired position.
    
    

If the command is aborted, convenience opening / convenience closing is halted.

Warning! Initialisation is important

A precondition for error-free operation of the anti-trapping mechanism is that the slide/tilt sunroof has been initialised! The slide/tilt sunroof must be initialised in service.

Emergency close and panic mode

Emergency closing is for deliberate closing of the slide/tilt sunroof without the anti-trapping mechanism (closing power limitation). It might be necessary to use this function in the event of an attack from outside or difficult mechanical actuation of the slide/tilt sunroof.
Emergency closing can be activated up to a speed of 16 kph.

Emergency closing is divided into 2 phases:

Phase 1:
Press the slide/tilt sunroof switch (towards closing) up to the mechanical limit position. After a short response time, the slide/tilt sunroof is closed at maximum speed.

When the slide/tilt sunroof switch is released, the slide/tilt sunroof is closed automatically (with anti-trapping mechanism). If the anti-trapping mechanism is detected, the closing action is aborted. The slide/tilt sunroof moves back and opens by approx. 20 cm.

Phase 2:
Releasing the slide/tilt sunroof switch in phase 1 and over-pressing the slide/tilt sunroof switch within approx. 1.5 seconds (after releasing) means that the slide/tilt sunroof is closed without the anti-trapping mechanism. Here, the slide/tilt sunroof is closed with maximum power and at maximum speed. In the event of blocking, the electric motor is supplied with current until the overheating protection is activated.
It is always possible to open the slide/tilt sunroof independently of the overheating protection.

Anti-trapping protection (closing power limitation)

Warning! Initialisation is important

A precondition for error-free operation of the anti-trapping mechanism is that the slide/tilt sunroof has been initialised! The slide/tilt sunroof must be initialised in service.

The anti-trapping mechanism is active across the entire range in the closing direction. The anti-trapping mechanism works as follows:

• The slide/tilt sunroof is opened by approx. 20 cm.
  
• With the closing action from the ”Lift” position, the roof returns to the ”Lift” position.
  

The anti-trapping mechanism does not prevent trapping as a general principle, rather it limits the maximum permitted trapping power (closing power limitation).
To prevent non-permitted high closing power, 2 Hall sensors are integrated in the electric motor. These Hall sensors can measure the closing speed. The closing speed is used to calculate the closing power.
The mechanical forces change with ambient temperature and ageing. For this reason, the closing power (characteristic curve) is relearned with every closing action, thus adapting the anti-trapping mechanism.
With each additional closing action, the currently required closing power is determined and compared with the characteristic curve. If the difference between the two power values exceeds the specified trigger threshold, the slide/tilt sunroof opens immediately. The anti-trapping mechanism can be disabled with the 'emergency closing' function (see 'Emergency closing').

In the event of failure of the anti-trapping mechanism (e.g. defective Hall sensor), no automatic closing is possible.

While the vehicle is being driven, disruptive influences can occur that influence the closing power. Disruptive influences are in particular strong vibrations, air-stream (slide/tilt sunroof in lifted position) and difficult actuation due to cold and soiling. These disruptive influences are detected. Unexpectedly difficult actuation due to soiling, ice or damage can be overcome by the emergency closing.

Safety functions

• Maximum motor running time
  If the slide/tilt sunroof does not reach an end position, the electric motor is switched off after 15 seconds.
  
• Overheating protection
  The heating of the electric motor is calculated in the SHD control unit based on a model. The available temperature signals are the outside temperature and inside temperature (via K-CAN). In addition, there is an electronic thermometer (transistor) on the board of the SHD control unit.
  
• Emergency operation
  In emergency operation, the slide/tilt sunroof can only be moved for 750 milliseconds at a time.
  Emergency operation is possible under the following conditions:
  
  • Coding of the SHD control unit invalid
    
  • Signal of a Hall sensor implausible
    
  • Initialisation incomplete
    
    
• Emergency operation
  With an electrical defect, there is an emergency actuating unit for the slide/tilt sunroof. Fold down the cover of the roof operating unit. Place the internal hexagon spanner from the on-board tool kit in the opening at the drive of the slide/tilt sunroof and move the roof in the desired direction.
  
  

Check Control messages

For the slide/tilt sunroof, 2 Check Control messages are possible. The Check Control messages are displayed with a Check Control symbol in the instrument cluster.

Notes for Service department

General information

Initialisation of the slide/tilt sunroof

After the following service tasks, an initialisation of the slide/tilt sunroof must be carried out:

• Replacement of the SHD control unit
  
• Repairs on the mechanical system of the slide/tilt sunroof (e.g. slide/tilt sunroof was moved mechanically using the emergency actuating unit or replacement of the electric motor of the slide/tilt sunroof)
  
• Other repairs (e.g. replacement of a glass sunroof)
  
  

The initialisation serves to adapt the anti-trapping protection to the slide/tilt sunroof.

Important: anti-trapping mechanism not active

The anti-trapping mechanism is not active during initialisation.

The initialisation procedure is divided into the steps 'standardisation and 'learning the characteristic curves'.

• During standardisation, the end stop of slide/tilt sunroof towards ”Lift” is learned. The SHD control unit uses this to calculate the end stops for opening and closing.
  
• When the characteristic curves are learned, the mechanical closing forces in the slide/tilt sunroof are recorded.
  
  

Comply with the following sequence for the initialisation:

• Terminal 15 ON
  
• Press the slide/tilt sunroof switch forwards up to the resistance point towards ”Close” (do not press beyond the resistance point) and hold pressed.
  

Note: Press and hold down the slide/tilt sunroof switch.

If the slide/tilt sunroof switch is let go during initialisation, the sequence must be repeated.

• After approx. 15 seconds, the operation starts automatically. The 2 glass sunroofs are raised. The electric motor continues to run until the end stop for the ”Lift” position has been found.
  
• Thereafter, the slide/tilt sunroof is opened up to the end stop and closed again.
  
• After the slide/tilt sunroof has been closed again and the electric motor has switched off, the slide/tilt sunroof switch can be released. After approx. 2 seconds, required for data storage, the slide/tilt sunroof can be operated again using the slide/tilt sunroof switch.
  
  

Notes on coding / programming

Important! After replacement of the SHD control unit, run the coding.

If coding is not carried out, there is a danger of malfunction (e.g. anti-trapping mechanism) or permanent battery discharge.

No liability can be accepted for printing or other errors. Subject to changes of a technical nature