Dynamic lateral support at dynamic seat, function - GF91.25-P-2013LEA
MODEL 221.0 /1 with CODE (432) Left and right dynamic multicontour seat as of model year 2010 /YoM 09 MOPF
Function requirements, general
- Circuit 15 ON
- Pressure supply active
- No on-board electrical system limp-home mode
- Status of pneumatic pump for dynamic seat control (M40/1) on interior CAN (CAN B) OK
The dynamic lateral support (dynamic function) requires circuit 15 to be switched on and v > 10 km/h. However, the status indication on the SPLITVIEW display (A40/10) (with code (867) SPLITVIEW) or COMAND display (A40/8) (without code (867) SPLITVIEW), already indicates the status as of c. 15R "ON".
Function description for dynamic lateral support, general
The dynamic lateral support function combines the advantages of a comfortable seat with those of a sport seat. For this, the lateral support is improved during cornering by means of an automatic pressure increase of the lateral support cushions (side bolsters) on the outside of the curve. Intensity can be adjusted in 2 stages.
The dynamic lateral support 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.
Abort conditions
- Inflation or deflation timeout
- Leak in one of the lateral support cushions
- On-board electrical system emergency running mode
- Timeout or no signal for steering angle data, lateral acceleration or yaw rate
Blocking
When the following fault is active, the function is blocked for the running ignition sequence:
- Inflation or deflation timeout.
The dynamic lateral support function is structured as follows:
- Start and end
- Program sequence
- Valve control
- Compressed-air supply
Start and end
The dynamic lateral support function is switched on or off via the front central operating unit. This is displayed on the SPLITVIEW display (with code (867) SPLITVIEW) or COMAND display (without code (867) SPLITVIEW.
By actuating the multicontour seat quick select button (A40/9s4) in the front central operating unit (A40/9), the menu for the multicontour seat is indicated on the SPLITVIEW display (with code (867) SPLITVIEW) or COMAND display (without code (867) SPLITVIEW); after selecting the driver or passenger seat with the rotary pushbutton (A40/9s11) select in menu submenu "Dynamic seat". Pressing the rotary pushbutton downwards or upwards or turning it enables the intensity of the "Dynamic seat" function to be adjusted in 2 stages or to be switched on or off.
Program sequence
The DYNAMIC function should combine the advantages of a comfortable seat with those of a sport seat. The left front dynamic seat control unit (N32/19) creates a base pressure in the air cushions and also provides better lateral support when cornering by briefly increasing the pressure in the cushions on the outside of the curve.
This essentially happens as a function of the current vehicle speed and the lateral acceleration. The intensity of the program can be adjusted in 2 stages using the front central operating unit:
- Stage 1 (discreet)
The cushion lateral supports on the outside of the curve have less pressure applied to them slower.
- Stage 2 (dominant)
The air cushion lateral supports on the outside of the curve have more pressure applied to them faster.
Valve control
Depending on the vehicle speed and lateral acceleration, the left front dynamic seat control unit actuates the valves of the lateral support air cushions. The valves are integrated into the dynamic seat control unit. The data on vehicle speed and lateral acceleration are transmitted by the central gateway control unit (N93) via the interior CAN. The central gateway control unit receives the data beforehand via the chassis CAN (CAN E) from the ESP control unit (N47-5).
Compressed-air supply
The compressed air supply, required for inflating the seat cushions, is provided by the pneumatic pump for dynamic seat control.
| Electrical function schematic for dynamic seat (FDS) | Model 221 | PE91.25-P-2050-97SAD | |
| COMAND controller unit, component description | A40/3 On vehicles with code (526) COMAND with single DVD drive (without navigation) or with code (527) COMAND APS with single DVD drive (with navigation) |
GF82.85-P-3136LE | |
| On vehicles with code (529) HIGH Class Japan | GF82.85-P-3136LEJ | ||
| On vehicles with code (530) COMAND APS USA (with navigation) | GF82.85-P-3136LEU | ||
| COMAND display, component description | A40/8 Vehicles without code (867) SPLITVIEW |
GF54.30-P-6110LE | |
| Front central operating unit, component description | A40/9 | GF54.21-P-4500LE | |
| SPLITVIEW display, component description | A40/10 Vehicles with code (867) SPLITVIEW |
GF54.30-P-6120LE | |
| Pneumatic pump for dynamic seat, component description | M40/1 | GF91.25-P-5204LE | |
| Dynamic seat control unit, component description | N32/19, N32/22 | GF91.25-P-5202LEA | |
| ESP control unit, component description | N47-5 Except model 221.095 /195 |
GF42.45-P-5118LE | |
| Central gateway control unit, component description | N93 | GF54.21-P-4170LE |