GF91.25-P-5220FQ Active Multicontour Seat Control Unit Component Description
GF91.25-P-5220FQ Active Multicontour Seat Control Unit Component Description
MODEL 218
- with CODE (432) Active multicontour seat
For vehicles with code (494) USA version only the driver seat is an active multicontour seat.
N32/19 Left front active multicontour seat control unit
N32/22 Right front active multicontour seat control unit (except code (494) USA version, passenger side)
Location
The left front active multicontour seat control unit (N32/19) and the right front active multicontour seat control unit (N32/22) are centrally located in the backrest frame of the driver seat or front passenger seat.
Tasks
- Inflating and deflating the multicontour backrest as per the request read in by the driver active multicontour seat button group (S109) or the front passenger active multicontour seat button group (S108)
- Actuation of massage function through the left front massage function actuator motor (M94) or the right front massage function actuator motor (M95), triggered by the Massage function button (S109s1) (driver) or the Massage function button (S108s1) (front passenger)
- Control of dynamic lateral support, triggered by the Dynamics button (S109s6) (driver) or the Dynamics button (S108s6) (front passenger)
- Adjustment of stored pressure values when memory function and storage of actual contours (with code (275) Memory package (electrically adjustable front seats)
- Shutoff of the respective function if the pressure valve responsible has overheated
- Reading in of voltage-coded driver active multicontour seat button group (S109) or front passenger active multicontour seat button group (S108)
- Communication through interior CAN (CAN B) with driver seat control unit (N32/1) or front passenger control unit (N32/2) (with code (275) Memory package (electrically adjustable front seats)
For vehicles with code (494) USA version only the driver seat is an active multicontour seat.
The tasks are subdivided as follows:
^ Reading in of sensors and signals
^ Evaluation of input factors
^ Actuation of components
Reading in of sensors and signals
These input factors are read in via the following connections:
^ Direct line
^ Interior CAN
Direct line
- Circuit 30g
- Tml. 31
The following sensors are read in via direct lines:
- Driver active multicontour seat button group (S109) or - Front passenger active multicontour seat button group (S108)
- A limit switch in the left front massage function actuator motor (M94) or - A limit switch in the right front massage function actuator motor (M95)
Interior CAN
The active multicontour seat control unit communicates over the interior CAN with:
- the driver seat control unit (N32/1); for adjusting and storing driver seat contours (with code (275) Memory package (electrically adjustable front seats)
- the front passenger seat control unit (N32/2); for adjusting and storing front passenger seat contours (with code (275) Memory package (electrically adjustable front seats)
- the active multicontour seat pneumatic pump (M40/1); for actuation of compressed air supply
- the front SAM control unit with fuse and relay module (N10/1) as router for the signals from the Electronic Stability Program control unit (N30/4) (vehicles without code (233) DISTRONIC PLUS) or the Premium Electronic Stability Program control unit (N30/7) (vehicles with code (233) DISTRONIC PLUS) for the dynamic and PRE-SAFE(R) function
Evaluation of input factors
The input factors read in are evaluated by the active multicontour seat control unit. Actuation of the air cushion of the contour insert in the seat is effected by the piezo valves integrated in the active multicontour seat control unit.
Actuation of components
The actuation of the components takes place via the following connections:
^ Direct line
^ Interior CAN
Direct line
The following components are actuated via direct lines:
- Status LEDs in the driver active multicontour seat button group (S109) or the front passenger active multicontour seat button group (S108) for indicating the respective two-stage massage or dynamic program
- Windings in left front massage function actuator motor (M94) or right front massage function actuator motor (M95)
- Main valve in left front massage function actuator motor (M94) or right front massage function actuator motor (M95)
Actuation of the air cushion of the contour insert in the seat is effected by the piezo valves integrated in the active multicontour seat control unit. The actuation of the air cushion in the massage insert is done through the seat massage function actuator motor, regulated by the active multicontour seat control unit.
Interior CAN
The active multicontour seat control unit communicates over the interior CAN with:
- the active multicontour seat pneumatic pump (M40/1); for actuation of compressed air supply
Design
The active multicontour seat control unit contains not only the intelligent circuit but also piezo sensors. These sensors are used to measure and monitor the pressure. The air pressures in the cushions are adjusted by the piezo valves integrated in the active multicontour seat control unit.
The 14-pin plug connects the active multicontour seat control unit to the active multicontour seat button group on the seat and the windings of the seat massage function actuator motor.
The 7-pin plug connects the active multicontour seat control unit via the driver seat control unit or the front passenger control unit (with code (275) Memory package (electrically adjustable front seats) with the interior CAN and the voltage supply. This coupling is also used to connect limit switches and the main valve of the seat massage function actuator motor.
Function
Short-term control
The short-term control is actuated following each adjustment process (manual adjustment, memory request, initialization) for a certain period of time. It compensates for excess pressure deviations from the specified pressure of each air cushion (cushion areas, connected to a pressure sensor, are jointly in the temporary control phase) within a parameterized time period. Vacuum deviations during this phase are not compensated for. This phase is used to immediately compensate for large pressure jumps when sitting down and leaning back in a comfort-oriented fashion.
Long-term control
After the short-term control, the long-term control becomes active for the active cushions, until it is reset by events with a higher priority.
Regulation in the specified period is almost imperceptible to the customer, and effected such that the mean value of the actual pressure adjusts to the specified pressure as part of the repeatability process over a certain period of time.
If an adjustment to the specified pressure cannot be achieved in several consecutive steps, a "gross leak" is detected. The affected cushion area is deactivated completely until the malfunction is no longer present.
Non-active air cushions (lumbar support) are deflated in increments to a pressure less than the minimum pressure.
Variants
There are no hardware variants for the active multicontour seat control unit. The assignment for driver or front passenger seat and the country or left-hand/right-hand drive vehicle assignment is also coded by the software.
For vehicles with code (494) USA version only the driver seat is an active multicontour seat.
