General Information

General Information

The Supplemental Restraint System (SRS) is designed to complement the seat belt to 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; the passenger airbag module located in the instrument panel on the passenger side, which contains a folded airbag assembly with inflator unit; the side airbag modules located in the front seats, which contain a folded airbag and inflator unit; the curtain airbag modules located inside the headliner, which contain folded airbags and inflator units. The SRS control module (SRSCM) impact detection function is performed by an electronic accelerometer that constantly measures vehicle acceleration and outputs a corresponding signal through amplification and filtering circuitry of the microprocessor. The SRSCM detects a frontal collision with the frontal impact sensor and a side collision with the side impact sensor, and determines airbag 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 illumination: When a malfunction is detected, the module sends a signal to the SRSCM indicator lamp located in the cluster. The MIL lamp indicates an SRS driver malfunction. When the ignition switch 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 GDS. However, if an internal malfunction code is recorded or a malfunction occurs, the malfunction should not 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 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 the front seat deployment 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 status.
10. 10
    Park the vehicle on a level surface to prevent damage to the rollover sensor. Turn the ignition OFF during SRSCM repair procedures.
11. 11
    After the repair procedure, check that the SRSCM operates normally.