GF68.50-P-0004FL Roller Sun Blind, Function
GF68.50-P-0004FL Roller Sun Blind, Function
- with CODE (540) Electric rear window roller blind
Function requirements, general
^ C. 15R On
^ Version coding "Roller sun blind present" active
^ Roller sun blind function enabled
^ Temperature protection not active (inside temperature T > 1 °C)
^ No overvoltage or undervoltage
The circuit 15 status is sent by the electronic ignition lock control unit (N73) to the interior compartment CAN (CAN B).
Roller sun blind, general
The roller sun blind consists of a vertically running roller blind with guide rails in the C-pillar operating according to the scissors principle. The roller sun blind is driven by the rear window roller sun blind motor (M24).
The rear window roller sun blind motor is actuated by the rear SAM control unit with fuse and relay module (N10/2).
The roller sun blind function comprises the following subfunctions:
^ Function sequence for retracting/extending roller sun blind
^ Function sequence for position recognition
^ Normalization function sequence
^ Function sequence for time control
^ Function sequence for temperature protection
^ Function sequence for emergency operation
^ Function sequence: error storage
Function sequence for retracting/extending roller sun blind
When the rear window roller sun blind button (N72/1s9) is actuated the roller sun blind retracts or extends depending on the last running direction.
The upper control panel control unit (N72/1) reads in the rear window roller sun blind button and transmits the status to the front SAM control unit with fuse and relay module (N10/1) via the instrument panel LIN (LIN 1).
It provides the switch status as signal to the interior CAN, which is read in by the rear SAM control unit. The rear SAM control unit then actuates the rear window roller sun blind motor.
A "soft-start" and "soft stop" is realized in the roller sun blind to prevent mechanical damage and distortion as well as noises. Shortly before reaching the end position (retracted or extended) the "soft stop" function uniformly decelerates to the stop within t = 0.5 to 1 s, the "soft start" accelerates accordingly.
The last running direction is stored in the rear SAM control unit, so that the roller sun blind is moved in the direction expected by the operator when the rear window roller sun blind button is actuated again.
If the rear window roller sun blind button is actuated a second time while a roller sun blind operation is already in progress, the roller sun blind stops and after t = 200 ms it is moved in the opposite direction.
Function sequence for position recognition
The location counter in the rear SAM control unit evaluates the signals from the Hall sensor integrated into the rear window roller sun blind motor. This allows a certain speed profile to be assigned or recognized on the basis of absent pulses, e.g. blockage.
The corresponding zero position is in the upper and lower blockage position (roller sun blind completely open or closed) and is determined by normalization. The counter is increased when extending and decreased when retracting according to the actuation direction of the roller sun blind.
Normalization function sequence
Normalization is learning-in both mechanical stops into the rear SAM control unit.
The normalization procedure can be actuated automatically or manually.
The function sequence for normalizing comprises the following subfunctions:
^ Function sequence for automatic actuation of normalization
^ Function sequence for manual actuation of normalization
Function sequence for automatic actuation of normalization
Normalization is actuated each time blockage is detected outside the normalization procedure.
If position marker values are not plausible (e.g. startup of new rear SAM control unit or new control unit software), normalization is also actuated. In this case it is necessary to actuate both mechanical stops.
This is accomplished as follows:
- The position marker is set to zero for both stops.
- The first stop is actuated the next time the function is actuated.
- The position marker of the other stop is set to zero after the end of the actuation.
- The second stop is actuated the next time the function is actuated. Now the normalization procedure is terminated.
Function sequence for manual actuation of normalization
When the rear window roller sun blind button is actuated until the end of the actuation, manual normalization is actuated.
This actuates the rear window roller sun blind motor and switches off by the blockage detection. The next time the function is actuated, an automatic normalization procedure is started.
Function sequence for time control
The rear window roller sun blind motor is actuated for t = 0 to 20 s by the rear SAM control unit regardless of the running direction of the roller sun blind.
At an on-board electrical system voltage of U < 10.5 V the actuation is increased by t = 2 s to ensure that it moves to the end position even under unfavorable conditions (low temperatures, sluggishness).
After expiration of this time the request is automatically terminated.
If the rear window roller sun blind button is actuated continuously for t > 30 s, this is recognized as "sticking". An error is stored in the rear SAM control unit and the signal is no longer relayed to the interior CAN.
Function sequence for temperature protection
Each request from the rear window roller sun blind motor is stored in the rear SAM control unit. If more than one request is present within a specified time, they are listed and compared with the threshold value stored in the rear SAM control unit. If the threshold value is exceeded, the rear SAM control unit switches off the rear window roller sun blind motor to prevent overheating.
A new request from the rear window roller sun blind motor is only possible after a cooling time stored in the rear SAM control unit.
Function sequence for emergency operation
If the value from the location counter is implausible, the rear window roller sun blind motor changes to emergency operation When changing to emergency operation, both position markers are set to zero so that a normalization can be started the next time possible.
Function sequence: error storage
If a defect is detected, the hardware outputs on the rear SAM control unit are deactivated until the next change c. 15R ON/OFF takes place.
To simplify troubleshooting in the event of implausible behavior of the roller sun blind, the following function statuses are edited for output via diagnosis or parameter acquisition.
Function sequence for fault storage comprises the following subfunctions:
^ Function sequence for current fault
^ Function sequence for last fault
^ Function sequence for last stopping reason
^ Function sequence for last actuation duration
^ Function sequence for maximum actuation duration
^ Function sequence for maximum power
^ Function sequence for motion counter
Function sequence for current fault
The status of the function requirements is stored with each request. If not actuated, it is easy to determine which condition was not fulfilled when the last button was pressed. This allows a current problem to be solved.
Function sequence for last fault
The status of the requirements is stored permanently if the system is not actuated after a request due to non-fulfillment of function requirements.
This allows determination of the cause of a one-time malfunction. This value is overwritten only by a new combination of unfulfilled requirements. Status of c. 15 is not considered, because it is generally an incorrect operation which should not overwrite actual errors.
Function sequence for last stopping reason
The rear window roller sun bind motor can be switched off for various reasons. The last stopping cause is stored by the rear SAM control unit.
Causes may be:
- New request during active actuation
- Recognition of blockage
- Expiration of maximum time for extending/retracting
- Command "Stop" via diagnosis
- Recognition of hardware fault
- Overvoltage
- Reaching target position
Function sequence for last actuation duration
The actuation duration is stored each time the roller sun blind is actuated in the rear SAM control unit.
Function sequence for maximum actuation duration
If the rear roller sun blind is not switched off due to a fault, an operation request or timer control, the maximum value of the actuation voltage for extending and retracting is stored separately. This allows determination of how the electrical and mechanical characteristics of the rear window roller sun blind motor can be controlled for various vehicle and under various operating conditions.
Function sequence for maximum power
The maximum measured current is stored. This also allows experience to be gained on the variation of electrical and mechanical characteristics.
Function sequence for motion counter
The counter is increased by one for each actuation. This allows determination of how often the rear window roller sun blind motor has run in a vehicle.
