Seats: Description and Operation

Lumbar Support

The lumbar support consists of two cushions which are inflated by means of a motor for lumbar support. The cushions are inflated or deflated to the required pressure one after the other beginning with the upper cushion. The pressure in the cushions is measured using a pressure sensor (regulating switch). The pressure sensor is located at the same height as the headrest and is integrated into the lumbar adjustment. Automatic adjustment of the lumbar support is carried out by actuating the switch for memory seat adjustment. The motor for lumbar adjustment is shown in Figure 611_98 together with both lumbar cushions. Automatic adjustment of the lumbar support is divided into two phases.

1. If the seat motors have not yet reached their required position, adjustment of the lumbar support is interrupted by releasing the switch for memory seat adjustment.
2. If the seat motors have reached their required position, adjustment of the lumbar support is completed after the switch for memory seat adjustment is released.










Electric motor for backrest adjustment
The backrest is adjusted by an electric motor with gear unit. A Hall-effect sensor is integrated into the electric motor which measures the actual position.







Switch for seat adjustment
Manual adjustment of the seat positions is carried out by actuating the three switches located on the driver's seat (front seat).

1,2,3. Fore-and-aft adjustment and height adjustment are carried out by actuating the switch in the positions shown in Figure 615_98.

4. The seat backrest can be brought into desired position
by actuating the switch.

5. The lumbar support is inflated or deflated by actuating the switch.







Figure 613_98 shows how the following system components are arranged under the front seat.
1. Control module
2. Electric motor for front height adjustment
3. Electric motor for seat adjustment
4. Electric motor for rear height adjustment