Activating/deactivating front passenger airbag

Fig 1: Identifying Occupant Weight Sensor (OWS) System Communication Links & Components

Courtesy of VOLVO CARS OF NORTH AMERICA.

Under normal conditions the information from the occupant weight sensor (OWS) system (7/93) is the basis for whether the supplemental restraint system module (SRS) (4/9) should activate or deactivate the front passenger airbag (8/31 8/32 and 8/124). The occupant weight sensor (OWS) communicates continuously with the supplemental restraint system (SRS) module on the local LIN bus. When a passenger weighing more than a certain weight is in the seat, the supplemental restraint system module (SRS) is informed by the occupant weight sensor (OWS). The control module software activates the front passenger airbag, which means that the airbag has full functionality in the event of a collision. At the same time the supplemental restraint system module (SRS) transmits a signal on the controller area network (CAN) to the upper electronic module (UEM) (4/70), with a request to switch off the passenger airbag disconnected warning lamp. The upper electronic module (UEM) then switches off the passenger airbag disconnected warning lamp.

If the weight on the front passenger seat is below a certain level the supplemental restraint system module (SRS) is informed by the occupant weight sensor (OWS). The control module software deactivates the front passenger airbag, which means that the airbag has no functionality in the event of a collision. At the same time the supplemental restraint system module (SRS) transmits a signal on the controller area network (CAN) to the upper electronic module (UEM), with a request to switch on the passenger airbag disconnected warning lamp. The upper electronic module (UEM) then lights the passenger airbag disconnected warning lamp. However there is an exception to this:

• The passenger airbag disconnected warning lamp will remain unlit if the occupant weight sensor (OWS) registers that the passenger seat is unoccupied. This means that the passenger airbag is deactivated.