Orthopedic seat (FDS) (from 09.2002, codes 433 and 434)
1 - Air cushion in the shoulder area (double}
2 - Side airbag
3 - Air cushion to support the upper and lower lumbar regions
Orthopedic seat (MCS)
1 - Two airbags in the shoulder area
2 - Two airbags on the sides
3 - Three airbags for lumbar support
4 - Switches
Heated seats
1 - Seat heating control via CAN; 2 - Activation of LEDs in the N69/3s7 door control unit via CAN; N25/6 - Rear seat control unit N69/4; N32/1 - Left front N69/4s6 seat adjustment control unit with memory; N32 / 2 - Control unit for adjusting the right front N69 / 4s7 seat with memory; N69/1 - Left front door control unit R13/1; N69/ls10 - Switch for heating modes 1 and 2 R13/2 or only mode 1 for seat heating; N69/ls11 - Seat ventilation switch or R13/3 seat heating mode 2 R13/4; N69/2 - Right front door control unit; N69/2s10 - Seat heating in modes ' and 2 or only in R13/5 mode 1 R13/6; N69/2sl 1 - Seat ventilation or heating mode 2 R13/7 seat R13/8; N69/3 - Left rear door control unit; N69 / 3S6 - Seat heating in modes 1 and 2 or only in mode 1; N69 / 3s - Seat ventilation or seat heating mode 2; N69/4 - Right rear door control unit; N69 / 4s6 - Seat heating in modes 1 and 2 or only in mode 1; N69 / 4s7 - Seat ventilation or decide 2 seat heating; R13 / 1 - Heated cushion for the left front seat; R13 / 2 - Heated cushion for the back of the left front seat; R13 / 3 - Heated pillow right front seat; R13 / 4 - Heated pillow back right front seat; R13 / 5 - Heated cushion left rear seat; R13 / 6 - Heated back cushion left rear seat; R13 / 7 - Heated pillow right rear seat; R13/8 - Heated back cushion right rear seat
Note. The description is given for the driver's seat and fully applies to the front passenger seat as well.
dynamic (orthopedic) seats (FDS) features a multi-contour adjustable backrest design with memory function (MMKL), as well as a dynamic side stop. The multi-contour backrest is provided by three groups of air cushions providing upper and lower shoulder, side and upper and lower lumbar supports. The shape of the surface and the stiffness of the backrest are manually adjusted by means of a group of corresponding switches on the driver's (S109) or front passenger (S108) seats and functions «dynamic lumbar support».
Dynamic cross stop (front seats)
Feature Requirements:
- Circuit 15 R On;
- Circuit 15 On:
- Voltage level adequacy (no up or down jumps);
- No overheating sensor signal,
- No air leaks from pillows.
Function activation/deactivation «dynamic cross stop» provided by the FDS pushbutton and controlled by the seat adjustment control module (N32/19). The fact of activation of the function is confirmed by the operation of the control LED built into the FDS button. After activating the function, the seat control module during cornering provides the required inflation of the side support cushions located on the outside of the steering curve. The necessary information about the current transverse overloads comes from the control module of the anti-skid system (N47) and transmitted by the central gateway control module (N93) from the CAN-C bus in the engine compartment to the cabin CAN-B bus. If the FDS data stream is interrupted for more than 2 seconds, the function is automatically deactivated.
The degree and rate of inflation of the airbags are adjusted on the second control level of the dashboard (A1).
Sports mode (state 1)
The pressure in the cushions of the side stops is built up faster and to a higher value.
Comfort mode (state 2)
The pressure builds up more slowly and to a lower value. The modules involved in the management of dynamic seat adjustments include:
- driver's seat control module (N32/19);
- Front Passenger Seat Control Module (N32/22);
- Central gateway control module (N93);
- Anti-skid control module (N47).
Stop activation priorities
- Priority 1. Lumbar support;
- Priority 2. Shoulder support (except individual rear seats);
- Priority 3: Cross stop;
- Priority 4: Dynamic Lumbar Support and Dynamic Side Supports (only for front seats).
If several control switches are used at the same time, only the function with the highest priority is activated.
Shutdown Criteria
Automatic deactivation of all functions occurs when the supply voltage level jumps. The overheating of the valves and the formation of air leaks can lead to the deactivation of the individual function.
Background functions
The group of lumbar support cushions functions with overlapping in pairs in a wave-like sequence. Since only one cushion is activated in each case, adjacent cushions are considered inactive, i.e. empty. The background functions listed below provide the appropriate conditions for maintaining the correct functioning of the pillows.
Air bleed mode for inactive airbags (accessory function)
By maintaining a constant pressure in the active cushion (residence period) air is vented from adjacent inactive cushions.
Background pressure relief
When air is bled from an active cushion, residual air from adjacent inactive cushions is also released at the time of pressure comparison.
Relief limit
When the destination point is reached at the end of the lumbar support wave, the active pillow is emptied on command from the switch, but no longer than within 1 minute.
Control functions
The control of the inflation of the individual cushions of the thrust areas is in each case carried out by the control module of the respective seat (N32/19 and N32/22) and imperceptible to the user while maintaining manual adjustments.
Additional adjustments are made, for example, in the event of pressure fluctuations due to changes in the position of the seated person, leaks in the air pumps, temperature changes caused by the activation/deactivation of the seat heating elements and heat flows from the air conditioning system/body of the seated person, etc.
Sudden pressure surges caused by changes in the sitting position are extinguished quickly and imperceptibly. Control parameters can be programmed during diagnostics.