Open/Close Vario Roof, Function - GF77.30-P-2004RD
Model 172.4
Function requirements, general
- Transport mode not activated (as of 01.06.2012)
- No overvoltage or undervoltage
- No engine start (circuit 50 Off)
- Position of Vario roof sensed
- Vehicle speed v < 5 km/h
- Trunk lid closed
- Trunk partition closed (up to 29.02.2016)
The hydraulic cylinders are actuated by the Vario roof control unit via solenoid valves in the Vario roof control hydraulic cylinder.
The corresponding position of the Vario roof is sensed by the Vario roof control unit over various limit switches.
Control points:
- Vario roof actuation switch
- Transmitter key (A8/1) (Comfort opening/closing function) When the Vario roof is opened or closed, actuators with high switch-on
When the transport mode is activated, it is no longer possible to open a closed Vario roof. The transport mode is activated at the factory before loading, remains active during delivery and is deactivated again by the dealer before handover to the customer. In active transport mode, the message "Transport mode" and the charge condition of the on-board electrical system battery are shown in the multifunction display in the form of a bar graph (G1) 40 stages.
The electronic ignition lock control unit sends the circuit status circuit 50 via the interior CAN to the Vario roof control unit.
The instrument cluster sends the vehicle speed to the Vario roof control unit over the interior CAN.
The Vario roof control unit directly reads in the status of the trunk partition limit switch and the trunk lid rotary tumbler switch in the trunk lid central locking motor.
The function requirements are checked during the entire opening and closing procedure of the Vario roof. If these function requirements are not fulfilled or an interior CAN message is missing for longer than t= 50 ms, the Vario roof opening and closing procedure is interrupted.
Vario roof, general
The Vario roof is operated electrohydraulically by actuating hydraulic cylinders.
The electric motor in the Vario roof control hydraulic unit actuates the hydraulic pump, which generates the required operating pressure.
current are actuated. However, to ensure operation of the Vario roof (without switch-off due to undervoltage), the Vario roof control unit activates these actuators with a time offset (t = 80 ms).
Emergency opening:
In the case of malfunction, the Vario roof can be actuated manually after opening the emergency opening valve.
The Vario roof comprises the following partial functions:
- Function sequence for opening/closing Vario roof
- Function sequence for relocking Vario roof
- Function sequence for Vario roof stop mode
- Function sequence for overload protection
- Function sequence for indicator and warning messages for Vario roof
Function sequence for opening/closing Vario roof
The Vario roof can be opened and closed manually or automatically. Manual opening and closing is only possible with circuit 15 ON and at a vehicle speed of v < 5 km/h. The electronic ignition lock control unit transmits the circuit status circuit 15 and the instrument cluster the vehicle speed to the Vario roof control unit via the interior CAN. When the Vario roof actuation switch is actuated, the Vario roof is opened or closed manually for the time the request is present. The Vario roof control unit directly reads in the status of the Vario roof actuation switch.
When the "Comfort opening/closing via transmitter key" function is actuated, the Vario roof can be opened or closed automatically. The left door control unit transmits the information "Convenience feature mode" and "Direction of convenience feature" to the Vario roof control via the interior CAN.
Before opening/closing the Vario roof, it is necessary for the Vario roof control to determine the momentary position of Vario roof (open, closed or valid intermediate position) (position search). The position search is started after reading in the actuation request. To define the momentary position of the Vario roof, the Vario roof control unit evaluates the signals of all limit switches. If no plausible position is recognized, the Vario roof opening/closing procedure is not started.
Trunk partition (as of 01.03.2016):
The trunk partition separates the stowage space for the open soft top from the remaining trunk. It consists of a plastic hood, which can be opened manually and is closed automatically when the Vario roof is opened. To close the plastic hood, it is moved by the trunk partition motor toward rear beyond the dead center position and then by the spring force to the lower end position.
The position of the trunk partition is sensed by the trunk partition closed limit switch. The Vario roof control unit directly reads in the status of the trunk partition closed limit switch and evaluates it. When the Vario roof is to be opened, the Vario roof control unit transmits the request to closing the trunk partition to the rear SAM control unit via the interior CAN. If the trunk partition is moved upward (open), it is lowered to the end position (closed). For this purpose the rear SAM control unit directly actuates the trunk partition motor.
When the trunk partition is not closed after a defined period of time (e.g. by a pinched piece of luggage), the corresponding message appears in the multifunction display of the instrument cluster.
The following illustration shows the opening procedure of the Vario roof:
| Picture position | Vario roof position | Rear shelf position | Tubular frame position | Limit switch | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| A | B (bottom) | B (top) | C | D | E | F | G | ||||
| 1 | closed | Top | closed | 1 | 0 | 1 | 1 | 1 | 0 | 1 | 0 |
| 2 | closed | Top | Intermediate position | 1 | 0 | 1 | X | X | 0 | 0 | 0 |
| 3 | closed | Top | Open | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 1 |
| 4 | Intermediate position | Top | Open | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 1 |
| 5 | Open | Top | Open | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 1 |
| 6 | Open | Intermediate position | Open | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 1 |
| 7 | Open | Bottom | Open | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 1 |
| 8 | Open | Bottom | Intermediate position | 0 | 1 | 0 | X | X | 1 | 0 | 0 |
| 9 | Open | Bottom | closed | 0 | 1 | 0 | 1 | 1 | 1 | 1 | 0 |
- A: Vario roof 'Closed' limit switch (left pin) (S69)
- B: Rear shelf limit switch (S69/4)
- C: Left Vario roof locked limit switch (S69/5s1)
- D: Right Vario roof locked limit switch (S69/5s2)
- E: Vario roof 'Stowed' limit switch (S69/11)
- F: Tubular frame "locked" limit switch (S118)
- G: Tubular frame "open" limit switch (S119)
Switch positions:
- 1: Switch actuated
- 0: Switch not actuated
- X: Switch in intermediate position (limit switch setting in corresponding intermediate step not relevant)
When the Vario roof is opened, first the front side windows are lowered completely to the short stroke position and then the rear side windows. Then the Vario roof is unlocked on the crossmember above the windshield.
Model 172.4
with code 494 (US version)
All four side windows are lowered completely.
The Vario roof control unit transmits the request "Actuate short stroke position" to the door control unit via the interior CAN. The door control units then actuate the front power window motors. The rear power window motors are actuated directly by the Vario roof control unit. Hall sensors are integrated into the power window motors. Their signals indicate the position of the side windows. The door control units transmit the information "Short stroke position actuated" to the Vario roof control unit via the interior CAN. The Vario roof control unit evaluates the signals from the hall sensors integrated into the rear power window motors.
During closing, first the front side windows are lowered completely to the short stroke position and then the rear side windows. When the Vario roof is completely closed, all four side windows are closed again (except on vehicles with code 494 (USA version)). On vehicles with code 494 (USA version), the side windows are not closed automatically.
Then the Vario roof control unit actuates the electric motor in the Vario roof control hydraulic unit. The hydraulic pump driven by the electric motor, generates the required operating pressure for the further motion of the Vario roof. Now the Vario roof control unit actuates the solenoid valve. Via hydraulic cylinders the tubular frame is moved opening the trunk lid toward the rear to a vertical position. Activation continues until the tubular frame limit switch is actuated.
Then the Vario roof control unit actuates the solenoid valve. The Vario roof is folded down toward rear by the Vario roof hydraulic cylinders and then stowed in the trunk. The rear shelf is folded up during opening. For this purpose the Vario roof control unit directly actuates the rear shelf drive electric motor. Activation continues until the rear shelf limit switch is actuated.
When the Vario roof is folded together and put down in the trunk (sensed by the Vario roof down limit switch), the Vario roof control unit actuates the solenoid valve. The tubular frame is moved by hydraulic cylinders and the trunk lid is closed toward front. Activation continues until the tubular frame limit switch is actuated.
During the entire movement, the message "Vario roof in operation" is output in the multifunction display of instrument cluster. The Vario roof control unit transmits the request to output the message to the instrument cluster via the interior CAN.
When closing, the Vario roof moves in the opposite direction.
Additional function requirements for relocking Vario roof
- Terminal 15 ON
The electronic ignition lock control unit sends the circuit status circuit 15 via the interior CAN to the Vario roof control unit.
Function sequence for relocking Vario roof
If the Vario roof is not locked correctly when opening or closed, the Vario roof can be relocked by repeatedly actuating the Vario roof actuation switch. The Vario roof is moved until it is closed completely or as long as the request is present. In contrast the to normal opening or closing procedure, the power window motors are not actuated.
The following function requirements valid for the normal opening and closing procedure are not relevant for the Vario roof relocking function:
- Power window error/power window positions
- Vehicle speed signals
If the side windows were closed previously by hand, they only move to the short stroke position. Only when the Vario roof is closed, all side windows are closed completely.
Additional function requirements for Vario roof stop mode
- Vario roof not in locked end position
Function sequence for Vario roof stop mode
- Circuit 15 ON for t = 7 min
- Circuit 15 OFF for t = 15 s
When the actuation request is activated and the opening or closing procedure of the Vario roof interrupted due to missing or incorrect input factors, the stop mode is activated.
During the stop mode, the solenoid valve is actuated, the Vario roof is fixed in place. When the opening or closing procedure of the Vario roof if enabled and a new actuation request is present, it is restarted or continued.
When the stop mode is active, the Vario roof is arrested upon:
However, when the Vario roof opening or closing procedure has not yet been enabled by the Vario roof control unit, the stop mode is reactuated when a new actuation request is received. The retention time increases automatically when:
- Circuit 15 ON for t = 7 min
- Circuit 15 OFF for t = 15 s
If a solenoid valve is defective, the stop mode is not started. After successful a Vario roof position search, the opening or closing procedure is continued at the point found.
Function sequence for overload protection
The unlocked Vario roof can be opened or closed in both directions as long as the temperature of hydraulic oil does not exceed T = 85°C. The hydraulic oil temperature sensor records the hydraulic oil temperature. The Vario roof control unit directly reads in the signal from the temperature sensor and calculates the hydraulic oil temperature. The Vario roof control unit actuates the overload protection of the Vario roof control hydraulic unit electric motor when the motor is thermally overloaded.
The outside temperature is included in the calculation of the hydraulic oil temperature. The outside temperature is recorded by the outside temperature sensor. The front SAM control unit directly reads in the signals from the outside temperature sensor, calculates the outside temperature and transmits the value to the Vario roof control unit via the interior CAN.
Open Vario roof from non-actuated state:
- Enable at T < 85°C
- Inhibit/interruption at T > 90°C
Close Vario roof and relock:
- Enable at T < 90°C
- Inhibit/interruption T > 98°C
Error evaluation of Vario roof control unit at outside temperature of T < - 15°C:
- No errors on hydraulic oil temperature sensor
- No display in instrument cluster in event of timeout errors
- No storage of timeout errors
Error evaluation of Vario roof control unit at outside temperature of T < - 15°C:
- Errors are stored
- Displays in instrument cluster are activated
Function sequence for indicator and warning messages for Vario roof
The Vario roof control unit evaluates the function of the Vario roof continuously. Malfunction is indicated in the multifunction display. For this purpose the Vario roof control unit transmits the corresponding information to the instrument cluster via the interior CAN.
The messages are displayed regardless of the circuit status circuit 15, because these messages are also output when the Vario roof is operated using the comfort opening/closing feature.
When the Vario roof control unit detects an unlocked Vario roof at a vehicle speed of > 8 km/h, it transmits the request to output an acoustic warning signal to the instrument cluster via the interior CAN. The instrument cluster than actuates the warning buzzer for a time of max. t = 10 s.
Then the warning output is inhibited by the warning buzzer and is enabled only after the following events:
- Circuit 15 OFF changes to circuit 15 ON
- Vario roof changes position
- Vario roof actuation switch actuated in opposite direction, relocking
- Actuating relocking function (after changing Vario roof actuation switch from "actuated" to "not actuated")
The warning buzzer is actuated regardless of the circuit status circuit 15, because this warning is also output when the Vario roof is operated via the comfort opening/closing feature.
When the stop mode is switched off, the instrument cluster actuates the warning buzzer for t = 20 s. Actuation is started t = 15 minute before switching off the stop mode.
The following table indicates possible control and warning messages according to their priority.
| Priority | Fault/operation | Symbol in multifunction display | Display text in multifunction display | Warning buzzer |
|---|---|---|---|---|
| 1 | Vario roof unlocked and speed v > 8 km/h | Vario roof | Completely locked (white or red) | Yes |
| 2 | Stop mode active (not dependent on circuit 15) or Vario roof operation (actuated, Vario roof unlocked) | Vario roof | Vario roof in operation (white) | No |
| 3 | Vario roof mode not possible (drive mode, speed v > 5 km/h) | Vario roof | REDUCE speed | Yes |
| 4 | Vario roof mode not possible (trunk partition open) | Arrow on closed trunk lid | Close trunk partition (white) | Yes |
| 5 | Vario roof mode not possible (trunk lid open) | Trunk lid | Close trunk lid (white) | Yes |
| 6 | Vario roof operation not possible (overtemperature on Vario roof control hydraulic unit or undervoltage when engine is running) | Vario roof | Soft top lowers (white) | Yes |
| 7 | Vario roof operation not possible (undervoltage when engine is OFF) | Vario roof | Start engine (white) | Yes |
| Function schematic for electric Vario roof | PE77.39-P-2050-97TAA | ||
| Overview of Vario roof system components (VR) | GF77.30-P-9996RD |