Front Multicontour Seat (MKS), Function - GF91.25-P-0005GWM
Model 463
as of model year 2019
with code PA9 (Seat Comfort package Plus)
Function requirements, general
- circuit 15R ON or
- Terminal 15 ON
- No on-board electrical system limp-home mode
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.
Function description of 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 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 function boosts the lateral support when cornering by automatically increasing the pressure in whichever lateral support air cushion is on the outside of the curve. This essentially happens as a function of the current vehicle speed, the turn rate and the lateral acceleration. Intensity can be adjusted in two stages.
The multicontour seat is also equipped with a massage function in order to prevent tension during long journeys.
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 secure the vehicle occupant.
The multicontour seat function comprises the following subfunctions:
- Function sequence for setting the air cushion pressure
- Function sequence for dynamic function
- Function sequence for the massage function
Function sequence for setting the air cushion pressure
The contours and the surface hardness of the backrest can be adjusted individually on the multicontour seat by inflating and deflating the air cushions.
The air cushions are arranged as follows:
- In the seat side bolsters of the backrest on the left and right
- in the upper lumbar area
- In the lower lumbar support area
Inflation and deflation are controlled via a menu in the head unit.
The head unit sends the adjustment requests via user interface CAN, electronic ignition lock control unit and interior CAN to the respective front multicontour seat control unit. The air supply that is required to inflate the air cushions is provided by the multicontour seat pneumatic pump. The respective multicontour seat control unit transmits the request via interior CAN to the multicontour seat pneumatic pump.
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.
An adjustment is aborted under the following conditions:
- Overvoltage or undervoltage
- Inflating or deflating timeout
- Leak in one or more air cushions
Function sequence for dynamic function
The dynamic function boosts the lateral support when cornering by automatically increasing the pressure in whichever lateral support air cushion is on the outside of the curve.
The dynamic function is operated via a menu in the head unit. Intensity can be adjusted in two stages:
- Stage 1 (weak): The cushion lateral supports on the outside of the curve have less pressure applied to them at a slower rate.
- Stage 2 (strong): The air cushion lateral supports on the outside of the curve have more pressure applied to them at a faster rate.
The head unit sends the "Dynamic function ON" request via user interface CAN, electronic ignition lock control unit and interior CAN to the respective front multicontour seat control unit. The air supply that is required to inflate the lateral support air cushions is provided by the multicontour seat pneumatic pump. The respective multicontour seat control unit transmits the request via interior CAN to the multicontour seat pneumatic pump.
Depending on the speed, turn rate and lateral acceleration, the respective multicontour seat control unit actuates the integrated valves of 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. The dynamic function is canceled under the following conditions:
- Inflating or deflating timeout
- Leak in one or both lateral support air cushions
- On-board electrical system emergency running mode
- Timeout error or no information on speed, turn rate or lateral acceleration
- Adjustment request through memory function
Function sequence for the massage function
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 backrest and four in the respective seat cushion which can be inflated and deflated independently of one another.
The massage function is operated via a menu in the head unit. The following possibilities are available for operation:
- Audio/COMAND control panel: The Audio/COMAND control panel transmits operation signals to the head unit via the telematics CAN.
- Touchpad: The touchpad transmits operation signals to the head unit via the telematics CAN.
- Voice control system: The head unit directly reads in signals from the driver hands-free system microphone.
- Head unit finger navigation pad and steering wheel "Back" button: The head unit finger navigation pad and "Back" button transmit operation signals to the head unit via the steering wheel electronics, steering wheel CAN, steering column tube module control unit, suspension FlexRay, electronic ignition lock control unit and user interface CAN.
- The operating menu can be called up on the upper control panel control unit via the vehicle button. The upper control panel control unit transmits the status of the "Vehicle" button to the head unit via the LCP-LIN, Audio/COMAND control panel and telematics CAN.
The following massage programs can be selected:
- "Hot Relaxing Massage for Back"
- "Hot Relaxing Massage for Shoulders"
- "Activating massage"
- "Classic massage"
- "Undulating massage"
- "Mobilizing massage"
- "Active backrest workout"
- "Active seat cushion workout"
The head unit sends the "Massage function ON" request via user interface CAN, electronic ignition lock control unit and interior CAN to the respective multicontour seat control unit. The air supply that is required to inflate the massage bladders is provided by the multicontour seat pneumatic pump. The respective multicontour seat control unit transmits the request via interior CAN to the multicontour seat pneumatic pump.
After activating a massage program, the respective multicontour seat control unit actuates the corresponding massage function control unit via massage component LIN. The respective massage function control unit controls the air supply to the massage bladders via the integrated valves and therefore implements 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 with which the backrest heater is also switched on. The massage function is interrupted for the following adjustments:
- Manual adjustment of air cushions
- Memory adjustment request
After the interruption, the massage starts in its sequential control system with the next upcoming massage step.
The massage function is canceled under the following conditions:
- Overvoltage or undervoltage
- Overloading of multicontour seat pneumatic pump in combination with active dynamic function
- Adjustment request via PRE-SAFE®
| Electrical function schematic for multicontour seat | PE91.25-P-2051-97ZGB | ||
| Overview of system components for electric seats | GF91.29-P-9992GW |