GF77.30-P-0001RC Vario Roof (VD), Function

GF77.30-P-0001RC Vario Roof (VD), Function
- refinement package
- as of model year 09

Function requirements, general
^ No engine start (c. 50 OFF)
^ Status of Vario roof recognized (determination of Vario roof position)
^ Temperature of convertible top mechanism hydraulic unit (A7/5) in valid range for corresponding actuation direction and type of actuation.
^ Speed signal < 5 km/h
^ Trunk lid closed
^ Luggage compartment separation closed

Function description for Vario roof system, general
The system allows automatically opening and closing of the Vario roof and the side windows. The function sequence is based on a electro-hydraulic combination.
The Vario roof is actuated electrically and the opening and closing procedure is supported hydraulically. When opening, the side windows are opened first. Then the Vario roof is unlocked at the upper frame of the windshield and folded together toward the rear over the passenger compartment and deposited in the rear.
When closing, the function sequence is performed in the opposite direction. The Vario roof is folded out of the rear toward the front and locked in the upper frame of the windshield. Then the side windows are closed (not on USA version, code (494)).

Basically the two following actuation possibilities for the Vario roof (VR) system are differentiated:
Closing/opening Vario roof with Vario roof actuation switch (S84s1).
- Vario roof comfort opening/closing with transmitter key (A8/1) (with code (880) Closing system with infrared remote control).
Since actuators with high switch-on currents are actuated for operation of the Vario roof, it is necessary for the power convertible top control unit (N52) to actuate the actuators specified below with a time offset (80 ms).

The actuators to be considered are:
- Convertible top mechanism hydraulic unit (A7/5)
- Left front power window motor (M10/3
- Right front power window motor (M10/4)
- Left rear power window motor (M10/5)
- Right rear power window motor (M10/6)

General interrupt conditions
- Overtemperature of convertible top mechanism hydraulic unit (A7/5)
- Failure of CAN message for longer than 50 ms

The Vario roof allows the following partial functions:
^ Closing/opening Vario roof function (with Vario roof actuation switch)
^ Vario roof comfort opening/closing with transmitter key
^ Search function of convertible top mechanism control unit
^ Vario roof Stop mode, function
^ Automatic raising/lowering of power windows depending on Vario roof control, function
^ Overload protection for temperature limits exceeded for convertible top mechanism hydraulic unit

The following partial functions are described in separated documents:
^ Subsequently locking of Vario roof, function
^ Vario roof indicator warning messages, function

Closing/opening Vario roof function (with Vario roof actuation switch)

Additional function requirements
- Circuit 15 ON
- Status of Vario roof recognized (determination of Vario roof position)

These functions requirements are checked during the entire Vario roof operation. If one of these function requirements is no longer fulfilled or in the event of failure of a CAN message for > 50 ms, the sequence is interrupted immediately.

Function
When opening or closing the Vario roof the side windows are also included in the operation by desmodromic valve control Desmodromic valve control means that first the side windows are lowered when the Vario roof is opened and then the Vario roof itself is opened. During closing, the Vario roof is closed first and then the side windows are moved up (not on USA version, code (494)). Desmodromic valve control of the side windows with the Vario roof prevents damaging the Vario roof operation resulting from collision. When the Vario roof actuation switch is actuated and held down, the Vario roof is opened or closed. The opening or closing actuation request of the Vario roof actuation switch is read in by the upper control panel control unit and relayed to the convertible top mechanism control unit via CAN B (interior CAN).

The signal is transmitted from the convertible top mechanism control unit to he left door control unit (N69/1) and right door control unit (N69/2) via interior CAN to actuate the left front power window motor (M10/3) and right front power window motor (M10/4). The left rear power window motor (M10/5) and right rear power window motor (M10/6) are actuated directly by the convertible top mechanism control unit.
In addition, the convertible top mechanism hydraulic unit is actuated by the convertible top mechanism control unit and the Vario roof is opened or closed hydraulically. The convertible top mechanism control unit is the central unit in the Vario roof (VR) system for receiving, transmitting and relaying signals. The signals are transmitted and received directly via interior CAN.

On USA version code (494) the side windows can only be closed with the power window switches. For this purpose, the side windows must be moved up with the power window switches after the Vario roof is closed.

The side windows can also be opened or closed centrally with the touch control function via the roof actuation switch (except code (494)). For additional information see function description on convenience feature (CF).

Additional termination requirements.
- Circuit 15 OFF

Vario roof comfort opening/closing with transmitter key (with code (880) Closing system with infrared remote control)

Additional function requirements fir opening/closing Vario roof comfort opening with transmitter key
- Circuit 15R OFF
- Status (position) of Vario roof recognized

Function
The functions Vario roof comfort opening/closing with transmitter key (comfort opening) are described in the separate function description "Convenience feature"

Additional termination requirements.
- Circuit 15 ON

Search function for convertible top mechanism control unit
The search function is started when an actuation request for the Vario roof is received. The convertible top mechanism control unit recognizes the position of the Vario roof via the search function. For this purpose, all limit switches and the signal from the trunk lid rotary tumbler microswitch (S88/1) are read in by the rear SAM control unit with fuse and relay module (N10/2) via interior CAN (CAN B). This determines the position of the Vario roof (open, closed or in a valid intermediate position). If a plausible position of the Vario roof is not recognized, the Vario roof operation is stopped and a corresponding warning message appears in the instrument cluster (A1).

Vario roof Stop mode, function

Additional function requirements for stop mode function
- Vario roof not in locked end position

Function
If the actuation request of the Vario roof operation is interrupted due to erroneous or incorrect input value, the Stop mode is actuated. During the stop mode, the solenoid valves in the convertible top mechanism hydraulic unit for the Vario roof are actuated so that the Vario roof no longer moves; the Vario roof is fixed in place. If the "Open or close Vario roof" operation is reenabled and another actuation request is present, the Vario roof operation is started or continued.

As soon as the Stop mode is activated, a warning message "Vario roof in operation" appears on the display of the instrument cluster. When the Stop mode is activated, the Vario roof is arrested upon:
- Circuit 15 ON for 7 min.
- Circuit 15 OFF for 15 s

If the sequence of the power convertible top control unit is not enabled, the Stop mode is reactuated when it receives an actuation request and the stop time is automatically increased:
- Circuit 15 ON for 7 min.
- Circuit 15 OFF for 15 s

If a solenoid valve responsible for Stop mode function is defective, the Stop mode is not started.

Automatic raising/lowering of power windows depending on Vario roof control, function

Additional function requirements
- Vario roof operation activated

Function
The windows are opened and closed together with the Vario roof to prevent being damaged by the Vario roof.
The Vario roof is actuated with the Vario roof actuation switch. The power convertible top control unit has the master function and therefore the highest priority correspondingly.
The left front power window motor is actuated by the left door control unit and the right front power window motor is actuated by the right door control unit.

The left rear power window motor and the right rear power window motor are actuated directly by the convertible top mechanism control unit. Desmodromic valve control of the side windows corresponds to manual actuation.

With code (494) it is only possible to close the side windows with the power window switch, however, not with the Vario roof switch and not via the transmitter key (A8/1). The side windows are not raised automatically with code (494).

Additional termination requirements
- Blockage detection
- Actuation request is rescinded
- Failure of message to interior CAN (CAN B) for longer than 50 ms

Overload protection for temperature limits exceeded for convertible top mechanism hydraulic unit
It is possible to actuate the unlocked Vario roof in both operation directions until a hydraulic oil temperature of 85 °C is exceeded.
The temperature sensor (A7/5b1) in the convertible top mechanism hydraulic unit (A7/5) actuates the thermic overload protection in the convertible top mechanism hydraulic unit when the motor is thermally overloaded.

Hydraulic oil temperatures in °C:

Open Vario roof from closed non-actuated state:
Enable < 75 °C
Disable/Interrupt >85 °C

Subsequently close or relock Vario roof:
Enable < 85 °C
Disable/Interrupt > 90 °C

Moreover, the outdoor temperature is considered when checking the Vario roof for failure. The outside temperature is measured by the outside temperature display temperature sensor (B14) and is read in by the driver-side rear SAM control unit with fuse and relay module (N10/1). It transmits the message to the convertible top mechanism control unit via interior CAN.

Error consideration of convertible top mechanism control unit at outside temperatures less than minus 15 °C:
- No error on temperature sensor of convertible top mechanism hydraulic unit
- No display in instrument cluster with time-out error
- No storage with time-out error

Error consideration of convertible top mechanism control unit at on outside temperature of greater than minus 15 °C:
- Errors are stored
- Displays in instrument cluster are activated