The rear window can be shaded with the electrically driven rear roller sund blind (special equipment). The rear roller blind is fitted to the rear parcel shelf. It is controlled by the DM door module control units and the IHKA A/C control unit. The control units communicate with each other via the K-CAN SYSTEM and K-CAN PERIPHERALS data buses.
The door module in the driver's door and the door modules in the rear doors receive the information for controlling the rear roller blind 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. The (comfort) functions triggered by the control unit are dependent on the length of time the button is pressed.
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 switch positions are transmitted via the K-CAN data bus to the door module. Pressing the button triggers in the IHKA control unit activation of the electric motor.
The buttons for the rear roller blind are located in the switch blocks in the rear doors. The switch blocks are connected to the door modules via the K-CAN data bus. Pressing the button 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 direction of rotation of the electric motor can be reversed. This reversal of direction enables the rear roller blind to be rolled up and down.
After terminal R is switched on (system initialization), the control unit assumes the position of the rear roller blind to be rolled up (at top). The rear 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 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.
The functions for rolling the rear roller blind up/down are triggered by operating the button in the driver's door switch block or by operating the button in one of the rear doors. Two functions are possible:
Briefly pressing a button only brings about activation of the rear roller blind.
The rear roller blind is activated immediately when a button is pressed for a long period. The side roller blinds are activated with a delay. All the side roller blinds follow the direction of movement of the rear roller blind with a delay.
To protect the drive against overloading, the rear blind control system has a function for detecting the blocking current. Blocking current detection serves to shut down the 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 system compares the current when the drive is blocked with the starting current of the electric motor in normal operating mode. The control system 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 every motor activation after max. 10 seconds.
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.