Activation the safety system
Comprehensive tests are used to define triggering thresholds for all possible types of accident. These result in varying triggering thresholds for activating the following restraint systems (follow national-market version):
- Seat belt tensioner
- Front airbags
- Side airbags
- Head airbags
| Item | Explanation |
|---|---|
| 1 | Front passenger airbag (one or two-stage, depending on the national-market version) |
| 2 | Front side airbag, passenger's side |
| 3 | Belt tensioner, passenger belt |
| 4 | Head airbag, passenger's side |
| 5 | Comb connector |
| 6 | Head airbag, driver's side |
| 7 | Belt tensioner, driver's seat belt |
| 8 | Front side airbag, driver's side |
| 9 | Driver's airbag (one or two-stage, depending on the national-market version) |
| Body CAN | Body CAN |
| Kl. 31 | Ground connection (Terminal 31) |
| Terminal R | Terminal R |
| MRS | MRS control unit |
The restraint systems are only triggered if 2 independent sensors simultaneously detect the corresponding threshold values. For example, a head-on collision is detected by the longitudinal acceleration sensor in the B-pillar airbag sensor on the driver's side and by the longitudinal acceleration sensor in the MRS control unit.
The MRS control unit calculates the direction of the impact and the accident severity from the data transmitted by the sensors. Depending on the accident severity, the electric fuel pump is switched off.
Two examples (head-on collision and side collision) are used to illustrate the activation of the various restraint systems:
- Head-on collision
The restraint systems (belt tensioner, front airbags) are triggered if a head-on collision is so severe that the triggering thresholds in the MRS control unit are exceeded.
The belt tensioners have a lower trigger threshold than the front airbags. This means that, depending on the severity of the accident, only the belt tensioner is triggered by the MRS control unit.
If the belt buckle switch is defective, the MRS control unit attempts to trigger the belt tensioner despite the fault signal. Depending on the accident severity, the electric fuel pump is switched off.
- Side collision
If the triggering threshold in the MRS control unit is exceeded, the side airbag and head airbag on the side affected by the collision are triggered (see national-market version). Depending on the accident severity, the electric fuel pump is switched off.