BMW 7 Series: Automatic Closing

With the exception of the luggage compartment lid button in the A-pillar, all luggage compartment lid buttons are able to initiate automatic closing.

This luggage compartment lid button cannot be used to start the automatic closing procedure.

Closing Luggage Compartment Lid

The luggage compartment lid can be closed by pressing the inner luggage compartment lid button, outer luggage compartment lid button or central double-lock button.

The junction box electronics wake a sleeping vehicle in response to the inner luggage compartment lid button being pressed. The junction box electronics send the request on the K-CAN2. The Car Access System with Comfort Access receives the request and initiates the automatic closing procedure.

In response, the HKL then executes the automatic closing procedure.

As soon as the status of the luggage compartment lid contact switch changes, the junction box electronics issue a notification on the K-CAN2. The central gateway module implements the signal on the K-CAN. The HKL then knows that the closing process has ended.

Manual Opening and Closing

Moving the Luggage Compartment Lid by Hand

It is possible to open or close an open luggage compartment lid at any time in any vehicle idle mode situation.

Three vehicle statuses govern the manual opening and closing procedure. These are:

• Luggage compartment lid lift active
• Luggage compartment lid lift in sleep mode
• Luggage compartment lid lift at terminal 30B OFF.

Luggage compartment lid lift active

While terminal 30B is switched on, detection of manual luggage compartment lid movements is straightforward.

The HKL detects luggage compartment lid movement by means of Hall sensors located in the spindle drive motors. The HKL evaluates the pulses of the Hall sensors and stores the current position of the luggage compartment lid.

This position is used as the starting position for subsequent luggage compartment lid movement.

Luggage compartment lid lift in sleep mode

The current position of the luggage compartment lid is stored in the HKL before the vehicle enters sleep mode.

Once the vehicle is in sleep mode, the HKL checks the Hall sensors on a cyclical basis. The vehicle is woken if a luggage compartment lid movement is detected. The HKL is then switched on and detects the luggage compartment lid being moved by hand.

Terminal 30B OFF

If terminal 30B is switched off, the power supply to the spindle drives is switched off and so too are the Hall sensors. In this situation, therefore, manual luggage compartment lid movements can no longer be detected.

If the position of the luggage compartment lid has been altered manually, the stored value would no longer match the current value.

At the next request, the luggage compartment lid is always closed first. The HKL detects the lower end stop from the status of the luggage compartment lid contact switch. This enables the current position of the luggage compartment lid to be compared with the stored starting position. The position of the luggage compartment lid is, in this way, newly referenced.

NOTE: If the luggage compartment lid movement is stopped before the lower end stop is reached, the luggage compartment lid will be opened the next time it is operated.

Since the position of the luggage compartment lid has not yet been referenced, the luggage compartment lid is only opened by as much it was previously closed.

Luggage Compartment Lid Movement Inhibit Conditions

The luggage compartment lid is not permitted to be operated in various situations. These situations include engine starting or driving or cases where there may be a risk of vehicle damage.

If luggage compartment lid operation needs to be inhibited while the luggage compartment lid is closing, an attempt is made to complete the movement that has commenced through to the end. For example, an attempt is made to complete luggage compartment lid movement until it closes while the vehicle is driving off. The luggage compartment lid lift will terminate actuation if the luggage compartment lid comes up against a blocking situation.

The inhibit conditions are listed as follows:

MOVEMENT INHIBIT CONDITIONS CHART

If the luggage compartment lid is reversing, the inhibit conditions are ignored and the luggage compartment lid movement is followed through to the end.

Additional Functions of the Luggage Compartment Lid Lift

Position Detection

The spindle drives are each integrated with a motor. The motor contains two Hall sensors. The Hall sensors are arranged with relative offset. This enables detection of the motor's direction of rotation. In addition, it is possible to draw conclusions as to the remaining path of the luggage compartment lid based on the Hall sensor pulses.

The complete movement range of the luggage compartment lid from "CLOSED" to "OPEN" is recorded during assembly in the works. The HKL therefore knows how many Hall sensor pulses were generated between lower and upper end stop of the luggage compartment lid.

The number of Hall sensor pulses corresponds to the distance covered by the luggage compartment lid. With this information, the HKL is able to determine the opening angle of the luggage compartment lid.

The path of the luggage compartment lid is subdivided into various segments. From the Hall sensor pulses, the HKL knows the segment in which the luggage compartment lid is positioned. If the luggage compartment lid is fully open, it is positioned within the range of the upper segment. From there, the luggage compartment lid is always moved in the closing direction.

COMPONENTS DESCRIPTION CHART

1. Upper segment
2. Range between the upper and lower segment
3. Lowermost segment

If the luggage compartment lid is in the range of the lower segment, i.e. closed, the luggage compartment lid is always moved in the opening direction.

The current position of the luggage compartment lid is stored by the HKL before it enters sleep mode. When the vehicle wakes up, the most recently stored position is used as the current position.

Fig. 42: Identifying Luggage Compartment Lid Segments F01

Obstruction Detection

Obstruction detection is active during the luggage compartment lid opening and closing procedure. An obstruction to luggage compartment lid movement during the opening procedure causes the luggage compartment lid to stop moving immediately. If the luggage compartment lid is obstructed in the closing direction, the HKL briefly controls the spindle drives in the opposite direction. If the luggage compartment lid remains obstructed, the HKL stops controlling the spindle drive motors.

There is no reversal of the direction of movement if the luggage compartment lid is obstructed as it opens or closes at the end stop.

Obstruction detection principle

The HKL evaluates the Hall sensor pulses in the spindle drive motors. The motor current is also recorded.

If the motor current increases and the Hall sensor pulses drop out, the HKL detects that the luggage compartment lid is being obstructed.

NOTE: Obstruction detection is deactivated during initialization of the luggage compartment lid lift. This allows the luggage compartment lid drives to be controlled with the maximum current available.

Repeat Interlock

The HKL is equipped with a repeat interlock to prevent the motors from overheating. The motor run-time is cumulated for the repeat interlock.

If the sum exceeds a maximum running time of 2 minutes, a new operation command will be rejected. An action that is already in progress always follows through to the end.

After a cooling phase of 6 minutes, it is possible for the motor to accrue a run-time of 2 minutes again.

The current motor run-time is stored by the HKL before it enters sleep mode.

The motor run-time of the repeat interlock is halved when the control unit is woken from sleep mode.

The repeat interlock is cleared in the event of a terminal 30B reset. This means that a motor run-time of 2 minutes is immediately available.

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