Design [2 of 4]

Belt retractor sensor (USA/CDN only)




The belt retractor sensor monitors the status of belt extension.
The belt retractor sensor sends information on the status of belt extension to the control module in real time. The control module then analyzes the obtained values and uses the results so that the belt force limiter can optimize belt force for the person occupying the seat.
There are two belt retractor sensors in the vehicle - one on the driver's side belt retractor and one on the front passenger side belt retractor.
Data is transmitted on the same cable used for power supply. There is a signal/power supply cable for each belt retractor sensor as well as a ground cable.
The adaptive belt force limiter, belt retractor, belt retractor sensor and belt tensioner are mounted in a unit. If there is a fault in any of these components, the entire unit must be replaced.

Seat position sensors (USA/CDN only)




The seat position sensor is used to determine the size of the person sitting on the seat. There are two seat position sensors in the vehicle - one under the driver's seat and one under the front passenger seat. The seat position sensors are directly connected to the supplemental restraint system module (SRS). The seat position sensors have separate signal cables to the control module and a common ground.
The seat position sensors comprise a Hall sensor that changes current strength based on the position of the seat. The seat position sensor has two classifications - small person or large person. Small person indicates that the seat is approx. 10 cm (4 in) or less from the front-most seat position. All other positions are classified as large person.
This information is used by the function for adaptive seatbelt force limiting.

Switch on/off, front passenger airbag (not USA/CDN)




This switch is used to activate or deactivate the front passenger airbag. The switch is on the side of the dashboard on the passenger side. The switch can only be accessed with the front passenger door open. The ignition key is used to change the position of the switch. When the switch is in the OFF position, all the stages of the passenger airbag are deactivated and the passenger airbag disconnected (PAD) warning lamp lights. When the switch is moved between OFF and ON, the two Hall sensors detect the position of the switch. The Hall sensors for the switch are directly connected to the supplemental restraint system module (SRS). Each Hall sensor is individually connected to the control module. The signal which is transmitted from the Hall sensors has two different current levels, depending on the position of the switch.
A diagnostic trouble code (DTC) is stored if the signal from the Hall sensors cannot be correctly interpreted. The control module may, depending on the fault, deactivate the passenger airbag. The PAD (passenger airbag disconnected) warning lamp lights if the passenger airbag is deactivated. If a fault is detected and the passenger airbag is not deactivated, the SRS warning lamp lights and a text message is displayed in the driver information module (DIM).

Note! The on/off switch for the front passenger airbag and occupant weight sensor (OWS) must not be installed in the vehicle together.

Occupant weight sensor (OWS) (USA/CDN only) (S40/V50)




The occupant weight sensor (OWS) consists of three interactive components:
- The pressure sensor, installed under the front passenger seat
- Belt force sensor, mounted in the seat frame on the outside of the front passenger seat
- Occupant weight sensor module, installed under the front passenger seat.
The pressure sensor and occupant weight sensor are linked via a hose. The pressure sensor registers the pressure to which the seat is exposed, for example when someone is sitting in the car. Information from the belt force sensor is also used to ensure the good performance of the system. The belt force sensor informs the occupant weight sensor module with what force the belt is tensioned. This is done because the pressure measured by the pressure sensor can be affected by the passenger fastening the seatbelt tightly. This means that the passenger exerts greater pressure on the seat than during normal seat belt use. The passenger is then interpreted as being heavier than he or she is. The occupant weight sensor module uses the information from both the pressure sensor and seatbelt force sensor to calculate the actual weight of the passenger. The occupant weight sensor (OWS) transmits continuous signals to the supplemental restraint system module (SRS) and occupant weight sensor (OWS) on the local CAN network. If the occupant weight sensor (OWS) does not function correctly the supplemental restraint system module (SRS) will:
- disable the front passenger airbag
- light the passenger airbag warning lamp (PAD) in the roof console
- light the SRS (supplemental restraint system) warning lamp and display the alert message in the driver information module (DIM).
If a fault occurs in any of the components the following should be noted:
- The pressure sensor and occupant weight sensor module must be replaced at the same time
- The seat belt force sensor is replaced separately.

Note! The on/off switch for the front passenger airbag and occupant weight sensor (OWS) must not be installed in the vehicle together.

Occupant weight sensor (OWS) (USA/CDN only) (C30)




The occupant weight sensor (OWS) consists of three interactive components:
- The pressure sensor, installed under the front passenger seat.
- Belt force sensor, mounted in the seat frame on the outside of the front passenger seat.
- Occupant weight sensor module, installed under the front passenger seat.
The pressure sensor and occupant weight sensor are linked via a hose. The pressure sensor registers the pressure the seat cushion is exposed to, for example when someone is sitting in the seat.
Information from the seat belt force sensor is also used to ensure the good performance of the system. The seatbelt force sensor informs the occupant weight sensor module what force the belt is tensioned with. This is done because the pressure measured by the pressure sensor can be affected by the passenger fastening the seatbelt tightly. This means that the passenger exerts greater pressure on the seat than during normal seatbelt use. The passenger is then interpreted as being heavier than he or she is.
Using information from both the pressure sensor and the seat belt force sensor, the occupant weight sensor module carries out calculations and classifications of what is affecting the system. This forms the basis for the recommendation that is communicated to the supplemental restraint system.
The occupant weight sensor (OWS) transmits continuous signals on the local controller area network (CAN), which the supplemental restraint system module (SRS) and occupant weight sensor (OWS) are connected to. If the occupant weight sensor (OWS) does not function correctly the supplemental restraint system module (SRS) will:
- disable the front passenger airbag
- light the passenger airbag warning lamp (PAD) in the roof console
- light the SRS (supplemental restraint system) warning lamp and display the alert message in the driver information module (DIM).
If a fault occurs in any of the components the following should be noted:
- The pressure sensor and occupant weight sensor module must be replaced at the same time
- The seat belt force sensor is replaced separately.

Note! The on/off switch for the front passenger airbag and occupant weight sensor (OWS) must not be installed in the vehicle together.

Adaptive seatbelt force limiter (USA/CDN only)





Warning! Never use an ohmmeter or similar tool to test airbags, inflatable curtains adaptive seatbelt limiters, adaptive steering column or seat belt tensioners. Disconnect airbags, inflatable curtains adaptive seatbelt limiters, adaptive steering column or seat belt tensioners before testing them. Failure to do so may result in accidental deployment. This could result in serious injury or death.

The adaptive belt force limiter improves the seat belt function in the event of a head-on collision when the airbag has been deployed. There are two adaptive belt force limiters in the car. These are located in top of the belt retractors, positioned at shoulder height on the driver's and front passenger seat belts.
The adaptive seatbelt force limiters are electrically separated from each other. The adaptive seatbelt force limiters have a pyrotechnic charge which adapts the seatbelt force to a lower level against the chest on activation.
The adaptive belt force limiter, belt retractor, belt retractor sensor and belt tensioner are mounted in a unit. If there is a fault in any of these components, the entire unit must be replaced.
The adaptive belt force limiter and lap belt tensioner use the same connections on the supplemental restraint system module (SRS). Thus, they cannot be connected at the same time in the vehicle.

Adaptive steering column (USA/CDN only)





Warning! Never use an ohmmeter or similar tool to test airbags, inflatable curtains adaptive seatbelt limiters, adaptive steering column or seat belt tensioners. Disconnect airbags, inflatable curtains adaptive seatbelt limiters, adaptive steering column or seat belt tensioners before testing them. Failure to do so may result in accidental deployment. This could result in serious injury or death.

When the adaptive steering column in the collision protection system is activated, a pin is deployed which makes the steering column longitudinally adjustable and thus collapsible. If the frontal collision exceeds a certain level the steering wheel is pressed into the dashboard to a greater degree than if the steering column were rigid.
The steering is not affected by the deployment of the pin. The pin is deployed by a pyrotechnical charge and is located in the center of the steering column. The collision protection system in the adaptive steering column only functions if the driver is wearing the seatbelt and if the airbag deploys. The entire steering column must be replaced if the collision protection system in the adaptive steering column has deployed.