Seat Occupant Classification Module - Air Bag: Description and Operation

GF91.60-P-4069LAU Weight Sensing System (WSS) Control Unit, Component Description
- as of Model year 2009 [model 216.3]
- with CODE (494) USA version
- as of 1.9.08 [model 221.1]
- with CODE (494) USA version

Component Identification:

Location
The WSS control unit is located in the seat frame of the front passenger seat.

Task
The WSS control unit has the following tasks:
^ Reading in of sensors
^ Evaluation of input factors

Reading in of sensors
The input factors are read in with the following connections:
^ Direct line

Direct line
The following sensors are read in via a direct line:
- Belt tension sensor (B48/3)
- Seat occupied recognition pressure sensor (B48/4)

Evaluation of input factors
The WSS control unit determines the weight (person or child seat) on the front passenger seat. This is determined via a pressure measurement in a gel mat filled with silicone. The pressure measurement is performed by the seat occupied recognition pressure sensor.

The tractive force at the belt is transmitted via the belt tension sensor to the WSS control unit.

The WSS control unit uses the pressure and belt tension to calculate the corresponding weight class and sends this to the central gateway control unit (N93) via interior CAN (CAN B). This routes the information via the chassis CAN (CAN E) to the restraint systems control unit (N2/7).