GF91.25-P-2001RI Dynamic Filling/Emptying of Air In the Air Cushions In the Multicontour Seat, Function
GF91.25-P-2001RI Dynamic Filling/Emptying Of Air In The Air Cushions In The Multicontour Seat, Function
- with CODE (404) Driver seat multicontour backrest
- with CODE (405) Front passenger seat multicontour backrest as of Model Year 09/YoM 08 model refinement package
Function requirements, general
^ Circuit 15R or circuit 15 ON
^ Pressure supply active
^ No on-board electrical system limp-home mode
Function description for dynamic inflating/deflating the air cushions in the multicontour seat (massage function), general
The "Dynamic lumbar support" massage function is started via the dynamic lumbar support adjustment switch (S109s1) (pulse button) and lasts approx. 8 min. An LED in the dynamic lumbar support adjustment switch indicates whether the program is active. It is a convenience function and lets the driver or front passenger relax in particular during longer trips.
The "Dynamic lumbar support" massage function is described on the driver seat for left-hand drive vehicles by way of an example, but this also applies for the front passenger seat.
Abort conditions
- Leak in one of the two lumbar support dual chamber air cushions,
- manual lumbar support adjustment,
- adjustment request based on memory,
- Electr. line or dynamic lumbar support adjustment switch has a short circuit to ground or is jammed.
Blocking
When the following fault is active, the function is locked for the current ignition sequence:
- Electr. line or dynamic lumbar support adjustment switch has a short circuit to ground or is jammed.
The "Dynamic lumbar support" massage function (pulse program) has the following structure:
^ Start and end
^ Program sequence
^ Valve control
^ Compressed-air supply
Start and end
An LED in the dynamic lumbar support adjustment switch indicates the massage function (pulse program). The program starts here after the dynamic lumbar support adjustment switch has been pressed and the LED comes on to indicate this. When the dynamic lumbar support adjustment switch is pressed again, the "Dynamic lumbar support" massage program (pulse program) stops and the LED goes out.
Program sequence
After the switch has been actuated, the air pressures of the air cushions in the lumbar area are stored by the left front multicontour backrest control unit (N32/15). Next, these air cushions are deflated and the actual program starts:
The lower and the upper dual chamber air cushions in the lumbar area are inflated and deflated alternately in two compression stages by the left front multicontour backrest control unit. Each pressure setting is kept for approx. 5 s before changing to the next state. The pressure difference between the deflated and the inflated lumbar support cushion is approx. 100 mbar. A wave motion is created by alternately inflating and deflating the lumbar support cushion. After approx. 8 min, the program is terminated automatically and the original air cushion pressures are restored.
Lumbar support: Curvature of spine in lumbar region
Valve control
The valves are actuated by the left front multicontour backrest control unit and are located in the actual multicontour backrest control unit.
Compressed-air supply
The pneumatic controller unit with convenience functions (A37) ensures the air supply required to inflate the air cushions.