BMW 7 Series: Lumbar Support In The Rear-Compartment Comfort Seat

Lumbar-support Adjustment

Using the lumbar support, the backrest can be individually adapted to the spinal column and thus ensures relaxed driving.

The button for the lumbar support adjustment is located on the side of the center armrest and is connected via the LIN bus to the seat module.

The lumbar support function is fully integrated into the seat module and is adjustable from terminal 30B ON.

The seat module requests the button status for the lumbar support adjustment via the LIN bus an on a cyclical basis. The button responds with the current status via the LIN bus.

The seat module evaluates the button status and if necessary activates the lumbar support pump and solenoid valves.

Lumbar support is provided by two inflatable air cushions in the backrest. The desired air cushion is inflated with air or deflated via four solenoid valves until such time that the button for the lumbar-support adjustment is released.

The pump for lumbar-support adjustment delivers the required air pressure. The pump and the solenoid valves are activated from the seat module.

The seat module stores the malfunctions with the lumbar support. In the service workshop, the fault code entry is read out using the diagnostic system.

Fault code memory entries can be:

• Short-circuiting
• Line breaks
• Motor is defective.

Active Seat Ventilation for the Rear-compartment Comfort Seat

The active seat ventilation allows the passenger to have individual cooling of the seat and backrest surfaces.

In the F01/F02, a new concept has been introduced for the active seat ventilation. This concept requires only two fans for each seat. The integrated automatic heating and air conditioning system provides the vehicle with climate-controlled air. This means there is sufficient fresh and climate-controlled air in the footwell in front of the rear seats. The fans draw some air from the footwell. The drawn-in air is routed via each air-conditioning pad to the seat and the backrest.

The active seat ventilation is available for the seat and backrest on the rear comfort seat and can be activated from status terminal 15 ON.

The seat module has sole responsibility for the active seat ventilation function. Stage 3 is engaged when the button is pressed for the first time. This sets a high fan stage for seat and backrest.

The next fan setting or OFF is selected on further pressing of the button.

AC STAGES CHART

After having been activated for a period in excess of 10 minutes, active seat ventilation is automatically switched down from Stage 3 to Stage 2.

NOTE: The active seat ventilation has 4-zone automatic air conditioning as a requirement. The buttons for the active seat ventilation are in the control panel of the automatic rear-compartment air conditioning.

Fig. 116: Identifying Buttons For Active Seat Ventilation

COMPONENTS DESCRIPTION CHART

1. Button, active seat ventilation, driver's side rear
2. Button, active seat ventilation, pass side rear

The air intensity of the active seat ventilation is coupled to the fan setting of the automatic rear-compartment air conditioning. This makes it possible to harmonize the fan noises in the rear compartment. The active seat ventilation therefore reaches its maximum value, when the automatic rear-compartment air conditioning is set to the maximum fan setting.

If the automatic rear-compartment air are activated based on a characteristic map conditioning is not switched on, then the fans that is stored in each seat module.

Switching on the Rear Active Seat Ventilation The automatic rear-compartment air conditioning evaluates the button status and sends it via the K-CAN.

The seat module evaluates the status, activates the active seat ventilation with the selected air-conditioning setting, and monitors the function.

Two fans are fitted in each seat. The fans are activated from the seat module depending on the selected setting.

An activated seat ventilation function remains stored for up to 15 minutes after the status terminal 15 OFF. The previously active fan setting for the seat ventilation is switched on again if in this time the status terminal 15 ON is received by the seat module.

The energy management system in the vehicle can deactivate active seat ventilation briefly depending on the vehicle's energy balance. The function indicator is retained however.

Function indicator

In order to indicate that the seat ventilation function has been activated, the seat module sends a request via the K-CAN to switch on the LEDs in the button. The automatic rear-compartment air conditioning switches on the LEDs.

Back lighting buttons

The footwell module sends the status of the terminal 58g ON via the K-CAN2. The central gateway module transfers the signal to the K-CAN. Then the automatic rear-compartment air conditioning receives the status terminal 58g ON and activates the back lighting.

NOTE: The indicators in the control panel of the automatic rear-compartment air conditioning use black panel technology. A detailed description of the black panel technology can be found in the Product Information "F01/F02 display and control elements".

Air-conditioning Pad

The air-conditioning pad has openings in the area of the seat and backrest surfaces. Air can be drawn in through the openings in order to control the temperature of the seat cover.

Special covers are required for active seat ventilation. The covers have very small air outlets.

The air drawn in by the fans can flow through the air outlets. This cools the seat cover and ensures that the temperature of the seat cover remains pleasant.

Fig. 117: Identifying Air-Conditioning Pad For Active Seat Ventilation In F01/F02 Rear-Compartment Comfort Seat

COMPONENTS DESCRIPTION CHART

1. Air-conditioning pad, backrest surface
2. Fans, seat ventilation
3. Air-conditioning pad, seat surface
4. Noise dampen for noise reduction
5. Fans, backrest ventilation
6. Adapter for air-conditioning pad, backrest surface

READ NEXT: