General Information

General Information

The Supplemental Restraint System (SRS) is designed to supplement the seat belt to help reduce the risk or severity of injury to the driver and passenger by activating and deploying the driver, passenger, side airbags, and seat belt pretensioners in certain frontal or side collisions. The SRS (airbag) consists of: the driver airbag module, located in the center of the steering wheel, which contains a folded airbag and inflator unit; the passenger airbag module, located in the instrument panel on the passenger side, which contains a folded airbag assembly with inflator unit; side airbag modules, located in the front seatbacks, which contain a folded airbag and inflator unit; curtain airbag modules, located inside the headliner, which contain folded airbags and inflator units. The impact detection function of the SRSCM is performed by an electronic accelerometer, which continuously measures vehicle acceleration and sends a corresponding signal through amplification and filtering circuits to a microprocessor. The SRSCM (SRS Control Module) detects frontal collisions using the frontal impact sensors and the internal acceleration sensors inside the SRSCM. For side impacts, the SRSCM detects side impact using 4 side impact sensors: 2 conventional acceleration sensors in the center pillar interior locations, and 2 pressure sensors in the side of the front door module, as well as the internal acceleration sensor inside the SRSCM. The SRSCM is designed to deploy the appropriate airbag module(s) using the sensor inputs described above.

1. 1
   DC-DC converter: The DC-DC converter in the power supply includes a step-up/step-down transformer converter and provides the ignition voltage for all circuits implemented as ASIC, and the internal operating voltage of the SRSCM itself. If the internal operating voltage falls below the critical set value, it will perform a reset.
2. 2
   Backup power supply: The SRSCM has a separate backup power supply that instantly supplies deployment energy in low-voltage conditions or in case of power failure during a frontal collision.
3. 3
   Self-diagnosis: The SRSCM constantly monitors the current operating state of the SRS and detects system malfunctions while the vehicle power is on. System malfunctions can be checked using trouble codes via GDS.
4. 4
   Airbag warning lamp illuminated: When a malfunction is detected, the module sends a signal to the SRSCM warning lamp located on the instrument panel. The MIL lamp will inform the driver that there is an SRS malfunction. When the ignition is switched on, the SRS lamp illuminates for approximately six seconds.
5. 5
   Trouble code recording: When a malfunction occurs in the SRS, the SRSCM stores the DTC corresponding to the malfunction. The DTC can only be erased using GDS. However, if an internal malfunction code is active or a failure is recorded, the malfunction reset cannot be performed.
6. 6
   Self-diagnosis connector: The data stored in the SRSCM memory is output to GDS or other external output devices through the connector located under the protective cover on the driver side.
7. 7
   After the airbag has deployed, the SRSCM must not be reused and must be replaced.
8. 8
   The SRSCM determines whether the passenger is wearing the seat belt by the signal from the built-in switch in the seat belt buckle and deploys the front seat airbag at each specified collision speed.
9. 9
   Side airbag deployment is determined by the SRSCM, which detects the satellite sensor impact signal in a side collision, regardless of the seat belt condition.