GF91.25-P-2021FL Manual Inflating/Deflating Dynamic Multicontour Seat Air Cushion, Function

GF91.25-P-2021FL Manual Inflating/Deflating Dynamic Multicontour Seat Air Cushion, Function
- with CODE (432) Left and right dynamic multicontour seat

Function requirements, general
^ Circuit 15R or circuit 15 ON
^ Pressure supply active
^ Status of pneumatic pump for dynamic multicontour seat (M40/1) on interior CAN (CAN B) okay
^ High voltage supply in left front dynamic multicontour seat control unit (N32/19) or right front dynamic multicontour seat control unit (N32/22) okay
^ Corresponding driver dynamic multicontour seat button group (S109) or passenger dynamic multicontour seat button group (S108) recognized as inserted

Manual inflating/deflating function, general
The contours and surface hardness of the backrest and seat cushion on the dynamic multicontour seat can be adjusted individually by inflating and deflating the air cushions with the dynamic multicontour seat button group.

The air cushions are located as follows:
- in lower lumbar support area
- in upper lumbar support area
- in left and right side bolsters on backrest
- in front area of seat cushion (seat cushion depth) (except code (494) USA version, passenger side)

The air supply, required for inflating the seat cushions, is supplied by the dynamic multicontour seat pneumatic pump.

Abort conditions
- Inflation or deflation timeout
- Leak in an air cushion with the corresponding function
- On-board electrical system emergency running mode
- The corresponding channel of the dynamic multicontour seat button group is short-circuited to ground or stuck

Blocking
When the following fault is active, the function is blocked for the running ignition sequence:
- Inflation or deflation timeout
- The corresponding channel of the dynamic multicontour seat button group is short-circuited to ground or stuck.

Manual inflation/deflation enables the following partial functions:
^ Seat cushion length adjustment (except code (494) USA version, passenger side)
^ Side bolster air cushion adjustment
^ Lumbar support up/down adjustment
^ Lumbar support adjustment +/-
^ Deflating functions
^ Short-term and long-term control

The manual inflation/deflation function is described at the driver seat for left-hand drive vehicles by way of an example, but this also applies for the front passenger seat.

Seat cushion length adjustment (except code (494) USA version, passenger side)
As long as the seat cushion length button (S109s5) is actuated in the direction "up arrow", the seat cushion length changes when inflating the seat cushion air cushion (until the maximum pressure is reached).

As long as the seat cushion length button is actuated in the direction "down arrow", the seat cushion length changes by deflating the seat cushion air cushion. In doing so the pneumatic valve remains opened after the minimum residual pressure is reached for no longer than t = 1 min (upon actuation).

Side bolster air cushion adjustment
The right and left air cushion lateral support can be inflated together to a maximum pressure by actuating the driver seat side bolster air cushion adjustment button (S109s2) n the direction "+" and deflated to a minimal pressure by actuating in the direction "-". In doing so the pneumatic valve remains opened after the minimum residual pressure is reached for no longer than t = 1 min (upon actuation).

Lumbar support up/down adjustment
The air cushions are adjusted manually by inflating or deflating with the lumbar support up/down adjustment button (S109s4).
As long as the toggle switch is actuated in direction "up arrow" the backrest contour in the lumbar area changes by deflating the lower air cushion and inflating the upper air cushion.

As long as the toggle switch is actuated in the direction "down arrow" the backrest contour in the lumbar area changes by deflating the lower air cushion and inflating the upper air cushion. In doing so the pneumatic valve remains opened after the minimum residual pressure is reached for no longer than t = 1 min (upon actuation).

Lumbar support adjustment +/-
As long as the lumbar support +/- (S109s3) is actuated in the "+" direction, the backrest contour in the lumbar area changes by inflating the presently activated upper or lower lumbar support air cushion. On reaching the maximum pressure, the inflation is stopped.

As long as the lumbar support +/- is actuated in the "-" direction, the backrest contour in the lumbar area changes by deflating the presently activated upper or lower lumbar support air cushion. In doing so the pneumatic valve remains opened after the minimum residual pressure is reached for no longer than t = 1 min (upon actuation).

Deflating functions
The cushions in the lumbar area are overlapping, and thus their function is linked during the wave sequence.

Limit stop deflation (deflation timeout)
Upon reaching the end point following the wave, the residual pressure in the air cushion is decreased in the corresponding area. In doing so the pneumatic valve remains opened after the minimum residual pressure is reached for no longer than t = 1 min (upon actuation).

Short-term and long-term control

Additional function requirements
- No adjustment active
- Massage function not activated

The short-term control compensates for overpressure deviations in the air cushions. It activates following every adjustment and only remains active for a shorter, parameterizable period of time. This function is used among others to compensate for sitting down or leaning back immediately and in a comfort-oriented fashion.

After the short-term control, the long-term control becomes active. Here, the pressure supply is regulated such that the specified pressure is always achieved. This is done almost without the customer noticing.