Multicontour Seat (MCS), Function - GF91.25-P-0001LF

Model 217

With Code 432 (Dynamic seats left and right)

Model 222

With Code 432 (Dynamic seats left and right)

Except Code 406 (Multicontour rear seat)

Courtesy of MERCEDES-BENZ USA

Function requirements, general

No undervoltage or overvoltage
Circuit 15R ON or circuit 15 ON

The electronic ignition lock control unit sends the status of circuit 15 via interior CAN to the multicontour seat pneumatic pump and to the multicontour seat control units.

Multicontour seat, general

The multicontour seat combines the advantages of a comfortable multicontour seat with those of a sport seat. The contour and surface hardness of the backrest and the seat cushion of the driver and front passenger seat can be changed individually. This is done by air cushions that can be inflated independently of each other.

The lateral support in the driver and front passenger seat is made possible by a basic pressure in the lateral support air cushions. The dynamic seat function boosts lateral support when cornering by automatically increasing the pressure in whichever lateral support air cushion is on the outside of the curve. Intensity can be adjusted in two stages. This essentially happens as a function of the driving speed, the turn rate and the lateral acceleration.

In order to prevent back tension during long journeys, the multicontour seat is also equipped with a massage function.

The air supply required for inflating the air cushions is supplied by the multicontour seat pneumatic pump. The respective multicontour seat control unit transmits the corresponding request via the interior CAN to the multicontour seat pneumatic pump.

PRE-SAFE®:

In critical situations, the seat contour of the driver or front passenger seat is automatically changed to achieve a favorable seat position and securing of the vehicle occupant.

The multicontour seat function comprises the following subfunctions:

Manually adjust air cushion
Dynamic seat
Massage

Manually adjust air cushion

The contours and surface hardness of the seat backrest and seat cushion on the multicontour seat can be individually adjusted by inflating and deflating the air cushions.

The air cushions are located as follows:

In the seat side bolsters of the seat backrest
in the upper lumbar area
in the center lumbar area
In the lower lumbar support area
In the shoulder area

Inflation and deflation of the different air cushions is done using a menu in the COMAND controller unit or in the head unit.

The various functions can be selected using the Audio/COMAND control panel or the touchpad. The Audio/COMAND display shows all the settings.

The following adjustment functions can be accessed by pressing the seat button or by going to the seat adjustments menu item in the vehicle menu:

Backrest side bolsters
Lumbar support
Shoulder

The Audio/COMAND operating unit or the touchpad sends the operation signals via the telematics CAN to the COMAND controller unit or the head unit. The COMAND controller unit or the head unit processes these signals, generates the corresponding image data and sends a switch-on request via the telematics CAN to the Audio/COMAND display. The image data is sent via the LVDS line or the HSVL line to the Audio/COMAND display. In addition, the COMAND controller unit or the head unit sends the adjustment requests via the user interface CAN, electronic ignition lock control unit and interior CAN to the respective multicontour seat control unit.

Model 217

with code 432 (Dynamic seats left and right)

Model 222

with code 275 (Memory Package (driver's seat, steering column and mirror))

with code 432 (Dynamic seats left and right)

Except Code 406 (Multicontour rear seat)

The adjustments of the driver or front passenger seat can be stored and called up again using the memory function of the electrical seat adjustment.

Short-term and long-term control:

The short-term control compensates for overpressure deviations in the air cushions. It activates following every adjustment procedure and only remains active for a short 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 driver or front passenger noticing.

The manual adjustment is aborted under the following conditions

Overvoltage or undervoltage
Inflation or deflation timeout
Leak in one or more air cushions

Dynamic seat

The dynamic seat function combines the advantages of a comfortable seat with those of a sports seat. To this end, the lateral support when cornering is enhanced through automatic pressure increase in the corresponding lateral support air cushion (seat side bolsters) that is on the outside of the curve. Intensity can be adjusted in two stages. The air supply, required for inflating the lateral support air cushions, is supplied by the multicontour seat pneumatic pump.

The dynamic seat function can be operated using the Audio/COMAND operating unit or the touchpad. All settings are shown in the Audio/COMAND display.

The dynamic seat menu can be accessed by pressing the seat button or by going to the seat adjustments menu item in the vehicle menu. The Audio/COMAND operating unit or the touchpad sends the operation signals via the telematics CAN to the COMAND controller unit or the head unit. The COMAND controller unit or the head unit processes these signals, generates the corresponding image data and sends a switch-on request via the telematics CAN to the Audio/COMAND display. The image data is sent via the LVDS line or the HSVL line to the Audio/COMAND display. In addition, the COMAND controller unit or the head unit sends the adjustment requests via the user interface CAN, electronic ignition lock control unit and interior CAN to the respective multicontour seat control unit.

The lateral support is adjusted by the respective multicontour seat control unit using a base pressure in the lateral support air cushions. When cornering, a brief application of pressure in the corresponding outside lateral support air cushions serves to additionally improve the lateral support. This essentially happens as a function of the current vehicle speed, the turn rate and the lateral acceleration.

The intensity of the program can be adjusted in two stages:

Dominant: The lateral support air cushions on the outside of the curve have more pressure applied to them faster.
Moderate: The lateral support air cushions on the outside of the curve have less pressure applied to them slower.

Depending on the speed, turn rate and lateral acceleration, the respective multicontour seat control unit actuates the integrated valves to inflate or deflate the lateral support air cushions.

The Electronic Stability Program control unit sends information on speed, turn rate and lateral acceleration over the suspension FlexRay, electronic ignition lock control unit and interior CAN to the respective multicontour seat control unit.

Abort conditions:

Inflating or deflating timeout
Leak in one of the two lateral support air cushions
On-board electrical system emergency running mode
Timeout error or no information on speed, turn rate or lateral acceleration
Memory adjustment request

Blocked:

In case of a inflating or deflating timeout, the function is blocked for the active driving cycle.

Massage

The massage function is a comfort function and helps the driver or front passenger to relax, particularly during longer trips. To implement the different massage programs, 14 individual massage bladders are located in the respective seat backrest, which can be inflated and deflated independently of one another. The air supply required to inflate the massage bladders is provided by the active multicontour seat pneumatic pump. The intensity of the massage function can be adjusted in two stages.

The massage function can be operated using the Audio/COMAND operating unit or the touchpad. All settings are shown in the Audio/COMAND display.

The massage menu can be accessed by pressing the seat button or by going to the seat adjustments menu item in the vehicle menu.

The following massage programs can be selected:

Hot relaxing massage for back
Hot relaxing massage for shoulder
Activating massage
Classic massage
Mobilizing Massage
Active workout

In vehicles as of model year 2018, the massage function can also be made via the voice control system. The head unit sends the corresponding request via the user interface CAN, electronic ignition lock control unit and interior CAN to the respective front multicontour seat control unit.

After activating the massage program, the respective multicontour seat control unit activates the corresponding front seat massage function control unit via the massage component LIN. The respective front seat massage function control unit actuates the integrated valves to inflate or deflate the massage bladders and execute the selected massage program.

During the "Hot Relaxing Massage for back" and "Hot Relaxing Massage for shoulders" massage programs, the hot stone function is active for which the seat backrest heating is also switched on.

The massage function is interrupted for the following adjustments:

Manual adjustment of lumbar support
Manual adjustment of lateral support
Manually adjustment in the shoulder area
Memory adjustment request

After the interruption, the massage starts in its sequential control system with the next upcoming massage step.

Abort conditions:

Overvoltage or undervoltage
Overloading of multicontour seat pneumatic pump in combination with active dynamic function
Adjustment request via PRE-SAFE®
Error in heater activation (only for hot stone programs)

	Electrical function schematic for multicontour seat		PE91.25-P-2051-97SEA
	Overview of system components for electric seats		GF91.29-P-9992LF