General Information

General

The Supplemental Restraint System (SRS) is designed to supplement the seat belt to reduce the risk or severity of injury to the driver and passenger by activating and deploying the driver airbag, passenger airbag, side airbags, and seat belt pretensioners in certain frontal or side collisions. The SRS consists of: the driver airbag module, located in the center of the steering wheel, which contains the folded airbag and inflator; the passenger airbag module, located in the instrument panel on the passenger side, which contains the folded airbag and inflator unit; the side airbag modules, located in the front seatbacks, which contain the folded airbag and inflator unit; and the curtain airbag modules, located inside the headliner, which contain the folded airbags and inflator units. The SRSCM impact detection function is performed by an electronic accelerometer, which constantly measures vehicle acceleration and outputs a corresponding signal through the amplification and filtering circuit of the microprocessor. The SRSCM (SRS Control Module) detects frontal collisions with the frontal impact sensor and side collisions with the side impact sensor to determine airbag module deployment.

1. 1
   DC/DC Converter: The DC/DC converter in the power supply unit includes a step-up/step-down transformer converter and provides the ignition voltage for the 2 front airbag ignition circuits and the internal operating voltage of the SRSCM. If the internal operating voltage drops below the critical setting value, it will reset.
2. 2
   Backup Power Supply: The SRSCM has a separate backup power supply that instantly supplies deployment energy in a low-voltage condition or in the event of a power failure resulting from a frontal collision.
3. 3
   Self-Diagnosis: The SRSCM constantly monitors the current SRS operating state and system malfunction detection. When the vehicle power is turned off, system malfunctions can be checked using the trouble codes via GDS.
4. 4
   Airbag Warning Lamp Illuminated: When a malfunction is detected, the module sends a signal to the SRS warning lamp located in the cluster. The MIL will indicate an SRS malfunction to the driver. When the ignition is turned on, the SRS lamp illuminates for approximately six seconds.
5. 5
   Diagnostic Trouble Code Recording: When a malfunction occurs in the system, the SRSCM stores the DTC corresponding to the malfunction. DTCs can only be erased using the GDS. However, if an internal malfunction code is recorded or a malfunction occurs, the malfunction code(s) cannot be cleared.
6. 6
   Self-Diagnosis Connector: Data stored in the SRSCM memory is output to the GDS or other external output devices through the connector located under the protective cover on the driver's side.
7. 7
   After airbag deployment, the SRSCM must not be reused; it 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 passenger airbag at each collision severity level.
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 status.