BMW 7 Series: System Circuit Diagram

System Circuit Diagram - Roller Sun Blind

Fig. 26: Roller Sun Blind System Circuit Diagram

COMPONENTS DESCRIPTION CHART

1. Driver's door switch cluster
2. Footwell module (FRM)
3. Junction box electronics (JB)
4. Front power distribution box
5. Switch cluster in rear passenger's side door
6. Motor for roller sun blind, rear passenger's side
7. Rear power distribution box
8. Motor for roller sun blind, rear window
9. Switch cluster in rear driver's side door
10. Motor for roller sun blind, rear driver's side

K-CAN2 - Body-CAN2
LIN-Bus - Local Interconnect Network bus
KI. 30B - Terminal 30, basic operation

Overview of Functional Principle

The functional principle of the electrically operated roller sun blinds is described in the following.

Pressure-sensitive Finger Guard for Side Window

The roller sun blind has no electronic pressure-sensitive finger guard! The mechanism and drive units are designed such as to rule out any danger for the occupants posed by excessively high forces.

Nevertheless, to prevent trapping, the roller sun blinds can only be extended when the corresponding side window is closed. However should a trapping situation occur, movement of the roller sun blind will be stopped.

The roller sun blind is then moved in the opposite direction in response to the next operational request. It is always possible to retract the roller sun blinds at the side windows.

The direction of roller sun blind movement that has already started can only be reversed 1.5 seconds after the button is pressed again.

Further button operation is ignored during the initial 1.5 seconds of roller sun blind movement. This function is intended to protect the operating mechanism of the roller sun blind.

Roller Sun Blind on Rear Window

The roller sun blind on the rear window can be operated by means of the roller sun blind switches. There are three operating points:

• Driver's door switch cluster

The junction box electronics receives the switch status via the K-CAN2.

• Switch cluster in rear driver's side armrest*
• Switch cluster in rear passenger's side armrest*.

*The junction box electronics cyclically evaluates the switches at the rear doors via the LIN-bus.

The roller sun blind for the rear window is raised or lowered by briefly pressing the switch.

A special function is activated when the switch for the rear window roller sun blind is pressed longer. This special function allows all three roller sun blinds to extend or retract to assume the same position.

In this function, the roller sun blind for the rear window is actuated and, if necessary, also the roller sun blinds for the side windows.

Every time the roller sun blinds are operated, their positions are stored in the junction box electronics.

The end stops are detected by the motors blocking, thus cancelling activation.

A repeat inhibit function is integrated in the system to prevent the motor overheating due to continuous operational requests initiated by children playing with the switch. The repeat inhibit blocks operation of the roller sun blind in the down position. Once started, movement of the roller sun blind is not interrupted by the repeat inhibit.

The renewed enable to raise the roller sun blind depends on the number of times the roller sun blind is operated and the intervals between operation.

Fig. 27: Identifying Rear Window Roller Sun Blind F01/F02

Position of roller sun blinds unknown

The raised or lowered positions of the roller sun blinds are stored in the junction box electronics. An unknown position of the roller sun blind may occur, for example, as a result of a voltage reset. If the position is not known, the junction box electronics interprets the roller sun blind as being in the raised position. The roller sun blind is then initially lowered in response to the next operational request. The direction is reversed if the junction box electronics detects blocking directly after actuation. Blocking signals that the roller sun blind is at the lower end stop position.

Blocking detection

The junction box electronics is equipped with a blocking detection facility to protect the motor. This function serves the purpose of immediately switching off the motor on reaching the upper or lower end position.

Motor actuation is additionally subject to a time monitoring function. Consequently, actuation of the motors is terminated after a defined maximum period of time.

The roller sun blinds on the side windows also feature a blocking detection function. This function is integrated in the electronic circuitry of the switch cluster in the rear door armrest.

This blocking detection function serves the purpose of switching off the motor on reaching the upper or lower end position.

The end positions are detected by evaluating the current consumption of the motors, thus cancelling activation.

After detecting a significant increase in current consumption, the motor is short-circuit braked in blocked position and the drive is briefly reversed to relief the strain on the mechanical system.

The actuation time of the motor for the roller sun blind is additionally monitored. The actuation time is limited to 15 seconds. Actuation is then terminated after this period of time has elapsed.

Child safety lock

The child safety lock function is switched on or off by means of the child safety lock switch in the switch cluster on the driver's side.

The roller sun blinds can no longer be operated with the rear switches when the child safety lock is switched on.

No request to raise or lower the roller sun blind is triggered when the child safety lock button is pressed.

Current movement of the roller sun blind is not interrupted when the child safety lock is engaged.

Roller sun blind switches

All switches have a LIN-bus connection. The switches are connected to terminal 30B and a ground connection.

The motors for the roller sun blinds in the side windows are connected directly to the respective switch cluster.

The motor for the roller sun blind on the rear window is connected to the junction box electronics.

The electronic circuitry for the LIN-bus and the power electronics for actuation of the motors are integrated in the switch cluster. The electronic circuitry monitors actuation and detects the end positions of the roller sun blind.

The junction box electronics receives information on the end positions from the LIN-bus.

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