Rear end collision, function - GF91.60-P-2004QMA

MODEL 209.3 /4 as of 1.6.04 with CODE (494a) USA version 

Chronological behavior over time of emergency tensioning retractor during a rear end collision, shown on model 202.0 

Fig 1: Identifying Rear End Collision Function - Shown On Model 202.0

Rear end collision 

The restraint systems control unit (N2/7) registers high vehicle acceleration caused by the rear impact. The restraint systems control unit (N2/7) relays the triggering pulse to the following components:

• Driver ETR [GUS] squib (R12/1)
• Front passenger ETR [GUS] squib (R12/2)(depending on seat occupancy)
• left rear ETR squib (R12/6)
• right rear ETR squib (R12/7)

The WSS (Weight Sensing System) control unit (N2/13) detects the occupancy of the front passenger seat with the aid of the pressure sensor (B48/4). In order to determine whether a child seat is present, the belt tension sensor (B48/3) is also read in by the WSS (Weight Sensing System) control unit (N2/13) and the relevant message sent to the restraint systems control unit (N2/7) via the Controller Area Network Bus class B (interior) (CAN-B). A front passenger seat that is unoccupied or occupied by a certified child seat is indicated by illumination of the automatic child seat recognition airbag OFF indicator lamp (N72/1e1) in the upper control panel control unit (N72/1). The front passenger ETR [GUS] squib (R12/2) is not deployed.