The side windows can be shaded with the electrically driven side roller blinds (special equipment, only in conjunction with rear roller blind). The side roller blinds are fitted to the rear doors. Each rear door has a roller blind for the door window and a roller blind for the quarter-light. The side roller blinds are controlled by the DM door module control units. The rear roller blind is controlled by the IHKA A/C control unit. The control units communicate with each other via the K-CAN PERIPHERALS data bus.
The door module in the driver's door receives the information for controlling the rear roller blind via the K-CAN data bus from the button in the switch block.
The door modules in the rear doors contain the master and activation functions for the side roller blinds. The door modules receive the information for activating the side roller blinds via the K-CAN data bus from the buttons in the switch blocks.
The IHKA control unit is fitted above the radio. The IHKA control unit contains among others the master and activation functions for the rear roller blind drive. The comfort functions triggered by the control unit are dependent on the length of time the button is pressed (one-touch or long-term pressing function).
The switch block in the driver's door incorporates the buttons for exterior mirror adjustment and power window operation and the button for the rear roller blind.
The information is transmitted from the buttons via the K-CAN data bus to the door module.
Pressing the button for the rear roller blind triggers in the IHKA control unit activation of the electric motor.
The buttons in the driver's door and rear door switch blocks have equal status in terms of their function.
The rear door switch blocks incorporate the buttons for the side roller blinds, the quarter-light roller blinds, the rear roller blind and a ”Right/Left” slide switch for selecting the functions on the left or right rear door.
The direction of rotation of the electric motor can be reversed. This reversal of direction enables the roller blinds to be rolled up and down.
After terminal R is switched on (system initialization), the control unit assumes the position of the side roller blind to be rolled up (at top). The side roller blind is rolled down when the button is operated for the first time. The direction of rotation is reversed once if the control system detects a blocking position (lower stop) immediately after the drive is activated.
One-touch or long-term pressing of a button initiates automatic rolling up/down of the side roller blinds (and the rear roller blind) to the upper or lower stop.
Intermediate positions cannot be selected.
Pressing a button while the blind is rolling up or down initiates a reversal of the operation, brought about by a change in the direction of rotation.
Rolling down the side roller blind is terminated only when the door window is open.
The current states (Open/Closed) of all the roller blinds are stored locally in the relevant control units. The direction of movement can thus be evaluated locally at the corresponding point.
The IHKA has the master function for the long-term pressing function. The side roller blinds are controlled centrally in the direction of movement of the rear roller blind.
As soon as a door module detects that the rear roller blind button is pressed, it transmits brief pressing information to the IHKA. If the button remains pressed for a longer period than that envisaged by the control system long-term pressing, long-term pressing information is also transmitted to the IHKA. Thus, in the event of long-term pressing, a reaction is identified at the rear roller blind while the side roller blinds follow this direction of movement with a delay.
A side roller blind can only be rolled up when the associated door window is closed (encodable). A door window is deemed to be closed up to a max. opening extent of 10 mm.
The side roller blinds can also be rolled down when the door windows are open.
If a button to roll up the side roller blind is operated when the door window is open, the blind is rolled up for a brief period only but then rolled down again immediately. This sequence indicates a non-permitted operation. The side roller blind is only rolled up when the door window is closed.
It is also possible to open a door window while the roller sun blind is rolled up.
A door window can be closed regardless of the position of the side roller blind.
To protect the drive against overloading, each door module has a function for detecting the blocking current. Blocking current detection serves to shut down the electric motor immediately after the upper and lower end positions (blocking positions) have been reached.
The current for the electric motor increases as soon as the drive reaches a blocking position. The control unit compares the current when the drive is blocked with the starting current of the electric motor in normal operating mode. The control unit detects from the difference in the currents that a blocking position has been reached and shuts down activation of the electric motor.
To protect the drive, the control unit terminates each motor activation after max. 10 seconds for the side roller blinds and the rear roller blind and after 6 seconds for the quarter-light roller blinds.
The functions can be reactivated after 90 seconds. Rolling functions that have already started are not cancelled. When the anti-repeat circuit is active, a one-off reversal of the direction of rotation is possible for rolling down.