GF91.25-P-2011T Manual Inflation/Deflation of Air Cushion on Dynamic Seat, Function

GF91.25-P-2011T Manual Inflation/Deflation Of Air Cushion On Dynamic Seat, Function
- with CODE (433) Left dynamic seat including multicontour seat
- with CODE (434) Right dynamic seat including multicontour seat

Component Identification:

Function (described on left front seat)
By manual actuation of switches:
^ Left front side cushion adjustment switch (S109s2)
^ Left front lumbar support adjustment switch (S109s3) or
^ Left front seat cushion fore/aft switch (S109s5)

the corresponding adjustment request is forwarded to the left front dynamic seat control unit (N32/19), which then actuates the valves in the air cushions accordingly. The air required to inflate the air cushions is generated by the pneumatic pump for dynamic seat control (M40/1).

If the left front seat cushion fore/aft switch (S109s5), left front side bolsters adjustment (S109s2) or the left front lumbar support adjustment switch (S109s3) is pressed for longer than 2 min, then the request from each switch is ignored and an error is stored. This also applies to the right-hand seat switch.

Actuation of left front seat cushion fore/aft switch (S109s5) towards "+"
As long as the rocker switch is pressed towards "+", the seat cushion length will change with a simultaneous inflation of the air cushion seat cushion (4) (until a max. pressure of roughly 300 mbar is reached).

Actuation of left front seat cushion fore/aft switch (S109s5) towards "-"
As long as the rocker switch is pressed towards "-", the seat cushion length changes by deflating the air cushion seat cushion (4). In doing so the pneumatic valve is opened after the minimum residual pressure is reached for no longer than t = 1 min (upon actuation).

Actuation of left front lumbar support adjustment switch (S109s3) towards "+"
As long as the cross-shaped rocker button is pressed towards "+", the backrest contour in the lumbar area is changed through inflation of the currently active air cushion upper or lower lumbar (2 or 3). Inflation is stopped upon reaching the maximum pressure of roughly 200 mbar per air cushion.

Actuation of left front lumbar support adjustment switch (S109s3) towards "-"
As long as the cross-shaped rocker button is pressed towards "-", the backrest contour in the lumbar area is changed through deflation of the currently active air cushion upper or lower lumbar (2 or 3). In doing so the pneumatic valves are opened after the minimum residual pressure is reached for no longer than t = 1 min (upon actuation).

Actuation of left front lumbar support adjustment switch (S109s3) towards "up arrow"
As long as the cross-shaped rocker button is pressed towards "up arrow", the backrest contour in the lumbar area changes sequentially through deflation up to a supply pressure p = more than 50 mbar of the air cushion lower lumbar (3), then inflation up to p = 100 mbar (dwell time t = 0.5 s) and finally deflation up to p = more than 50 mbar of the air cushion upper lumbar (2), then inflation up to p = 100 mbar of the air cushion lower lumbar (3). In each case only the air cushion upper or lower lumbar (2 or 3) is actuated. Entry into this so-called wave cycle ensues depending on which air cushion lumbar is active at any given time.

Actuation of left front lumbar support adjustment switch (S109s3) towards "down arrow"
As long as the cross-shaped rocker button is pressed towards "down arrow", the backrest contour in the lumbar area is sequentially changed by deflation up to a supply pressure p > 50 mbar of the air cushion upper lumbar (2), then inflation up to p = 100 mbar (dwell time t = 0.5 s) and then finally deflation up to p > 50 mbar of the air cushion lower lumbar (3), and then inflation up to p = 100 mbar of the air cushion upper lumbar (2). In each case only the air cushion upper or lower lumbar (2 or 3) is actuated. Entry into this so-called wave cycle ensues depending on which air cushion lumbar is active at any given time.

Leakage detection for air cushion upper and lower lumbar, and seat cushion
If in the air cushion upper (2) and lower lumbar (3), and seat cushion (4), the specified pressure value is not reached after 10 successive pressure increases, then such a status is deemed to be a gross leak and the appropriate air cushion is deactivated. In addition to this an error is stored, which can then be read out using STAR DIAGNOSIS.

Actuation of left front side cushion adjustment switch (S109s2) towards "+"
The air cushion lateral supports (1) can be inflated to maximum pressure when the switch is pressed towards "+". Inflation is stopped once the maximum pressure of roughly 450 mbar is reached.

Actuation of left front side cushion adjustment switch (S109s2) towards "-"
Pressing the switch towards "-" causes the air cushions to be deflated to a minimum pressure. In doing so the pneumatic valve is opened after the minimum residual pressure p = 15 mbar is reached for no longer than t = 1 min (upon actuation).

If the left front side cushion adjustment switch (S109s2) is pressed for longer than 2 min, the switch signal is ignored and an error is stored. This applies equally to the right-hand seat.

Leakage detection for air cushion lateral support (1)
If the leakage value is > 10 mbar/min, a gross leak is detected and the lateral support function is deactivated.

Actuation of several switches
If several switches are pressed simultaneously, only the adjustment with the highest priority is performed.
Priority 1: Lumbar
Priority 2: Seat cushion
Priority 3: Lateral support
Priority 4: Pulsation or dynamic lumbar

All functions are interrupted if there is an overvoltage or an undervoltage. In the event of excess temperature in a valve, the relevant function is then deactivated.

Background functions
In a group of cushions the cushions are arranged as overlapping and thus their function during the wave cycle is coupled. As for each group of cushions only one air cushion is active, the adjacent cushions are not deemed to be active (empty).

To ensure that this is the case, the following background information is required:
^ Dead-time deflation
While pressure is maintained in the active air cushion (dwell time), the adjacent non-active cushions are deflated.

^ Background deflation
If an active air cushion is deflated, then the residual pressure in the adjacent non-active air cushions is also reduced, as soon as the air cushions exhibit the same pressure.

^ Limit stop deflation
If following the wave cycle towards "down arrow" the limit stop is reached, then the residual pressures in the air cushions for each area are reduced, as long as the switch is pressed towards "down arrow", but not for longer than t = 1 min.