GF91.60-D-0002H Supplemental Restraint System (SRS), Function

GF91.60-D-0002H Supplemental Restraint System (SRS), Function

- with CODE (SH6) Thorax bag for driver (in seat backrest)
- with CODE (SH7) Thorax bag for driver and front passenger (in seat backrest)
- with CODE (SH9) Window bag for driver and front passenger

The Supplemental Restraint System (SRS) serves to protect vehicle occupants from injury in various types of accidents. The vehicle's SRS comprises the following airbag and belt tensioning units:
- Driver emergency tensioning retractor unit with driver GUS squib (R12/1)
- Front passenger emergency tensioning retractor unit with passenger GUS squib (R12/2)
- Driver airbag with driver airbag squib (R12/3)
- Front passenger airbag with front passenger airbag squib (R12/4)
- Left Window bag with left window bag squib (R12/16),
- Right Window bag with right Window bag squib (R12/17),
- Driver thorax bag with driver thorax bag squib (R12/32)
- Front passenger thorax bag with front passenger thorax bag squib (R12/33)
- Center front passenger emergency tensioning retractor unit with center front passenger GUS squib (R12/34)

The Highline airbag control unit (N2/15) triggers the airbag and emergency tensioning retractor units necessary to provide optimum passenger protection depending on the type and severity of the accident. For deployment, the following input variables are considered:
- Acceleration values of the sensors integrated in the Highline airbag control unit
- Acceleration values of the driver Side bag sensor (A53) and the front passenger Side bag sensor (A54)

With the driver seat, the switched status of the driver seat belt buckle switch (S68/1) is additionally taken into account.

In the case of rear-end collisions and minor front-end collisions, only the emergency tensioning retractors are triggered. In the case of more severe front-end collisions, the front airbags are also triggered. In the event of a side impact in which the lateral acceleration values of the driver Side bag sensor or the front passenger Side bag sensor are exceeded, the relevant thorax bags are triggered.

These are mostly designed as a combination of Window bag and thorax bag.

At the same time as the respective airbag and emergency tensioning retractor units are triggered, the Highline airbag control unit issues an accident signal to various control units:
- To the ME control unit (N3/23) for switching off engine 272. The accident signal is sent via the Controller Area Network bus class B (interior) (CAN-B) to the EZS control unit (N73) and from there via the Controller Area Network Bus class C (engine compartment) (CAN-C) to the ME control unit.
- To the CDI control unit (N3/21) for switching off engine 646 or to the CDI control unit (N3/20) for switching off engine 642. The accident signal is sent via CAN-B to the EZS control unit and from there via CAN-C to the respective CDI control unit.
- On vehicles with code (H12) Auxiliary heater (warm water) or with code (HZ5) 10 kW warm water auxiliary heater with timer to the warm water auxiliary heating control unit (N33/3) for shutting off the fuel-operated stationary heater via CAN-B.
- To the driver door control unit (N69/1) for emergency opening the driver door via CAN-B.
- To the SAM control unit (N10) for emergency opening the right or left sliding door and the rear-end door as well as for actuating the hazard warning system. The hazard warning system can be switched off again using the hazard warning system switch (N72/1s6).
- To the EZS control unit for opening all doors redundantly and for transmitting the crash signal to CAN-C for shutting off the engine.

As a "function check" is not possible for the SRS, we will refrain here from providing a description of the individual triggering strategies.

Furthermore, the triggering strategies are subject to modifications, such as those resulting from new knowledge gained in the area of accident research.

System monitoring

SRS malfunctions are indicated by the SRS warning lamp (A1e22) and the multifunction display in the instrument cluster (A1). For this purpose, the instrument cluster (A1) receives the corresponding message from the Highline airbag control unit via CAN-B.

Diagnosis

Diagnosis takes place via STAR DIAGNOSIS.

Disposal

When handling and disposing of airbag and emergency tensioning retractor units, the corresponding safety and disposal information in the work instructions must be fully observed.