Dynamic lateral support at dynamic seat, function - GF91.25-P-2013LE

MODEL 216.3 with CODE (432) Left and right dynamic multicontour seat as of model year 2009 /YoM 08 

MODEL 221.0 /1 with CODE (432) Left and right dynamic multicontour seat as of model year 2009 up to 2010 /YoM 08 up to YoM 09 

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 on the COMAND display (A40/8) (without code (867) SPLITVIEW) or SPLITVIEW display (A40/10) (model 216 as of YoM 09 with 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 COMAND display or SPLITVIEW display (model 216 as of YoM 09 with code (867) SPLITVIEW).

Pressing the multicontour seat quick select button (A40/9s4) in the front central operating unit (A40/9) activates the menu for the multicontour seat on the C'OMAND display; after selection of the driver or front passenger seat using the rotary pushbutton (A40/9s11) in the menu, select the "Dynamic seat" submenu.

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. This data is sent via the interior CAN by the central gateway control unit (N93). 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-2050-97SAC
		Model 216	PE91.25-P-2050-97CAB
	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 Except 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 Model 216 as of model year 10 /YoM 09 with code (867) SPLITVIEW	GF54.30-P-6120LE
	Pneumatic pump for dynamic seat, component description	M40/1	GF91.25-P-5204LE
	ESP control unit, component description	N47-5 Except model 221.095/195	GF42.45-P-5118LE
	Dynamic seat control unit, component description	N32/19, N32/22	GF91.25-P-5202LE
	Central gateway control unit, component description	N93	GF54.21-P-4170LE