1. DC-DC Converter: Located in the power supply unit, it contains a step-up/step-down converter and provides operating voltage to the SRS unit, as well as voltage to the ignition circuits of the two front airbags in the event of a collision. If the operating voltage of the system drops below the specified critical value, the system is rebooted.
2. Redundant power circuit: The SRS unit has a redundant power circuit that supplies voltage to the air bag deployment circuit when the main power supply voltage drops or is lost in the event of a frontal collision.
3. Self-diagnosis: When the vehicle power is on, the SRS unit constantly monitors the status of the passive safety system and detects its malfunctions, the codes of which can be checked using a scanner.
4. Airbag warning lamp illuminates: When a fault is detected, the module illuminates the SIR system malfunction indicator lamp in the instrument cluster. When this indicator light illuminates, it indicates a malfunction in the SRS system. When the ignition key is turned to the "ON" position, the SIR indicator light illuminates for approximately six seconds.
5. Malfunction Code Registration: When a malfunction is detected, the SRS unit registers the corresponding malfunction code. The fault code can only be cleared using a scanner. However, in cases where an internal failure or collision is detected, the codes should not be cleared.
6. Self-diagnosis connector: Data from the SRS unit memory is output to a scanner or other external device through the connector located at the bottom of the dashboard on the driver's side.
7. Once the airbags have deployed, the SRS unit cannot be reused and must be replaced.
8. The SRS unit determines whether the passenger is wearing a seat belt based on a signal from the switch in the passenger seat belt buckle and commands the front seat airbag to deploy when a predetermined collision speed is reached.
9. The command to deploy the side airbag is issued by the SRS unit upon receiving a signal from the side impact sensor, regardless of the position of the seat belt.
Only specially trained personnel are allowed to perform work on the airbag system. Therefore, the performance of such work should be preceded by a careful study of this Manual. When working on the airbag system, strict safety precautions must be taken to prevent injury to service personnel (in case of accidental deployment of the airbag) or the driver (due to the failure of the airbag).
The driver airbag module (DAM), passenger airbag module (PAM), includes the airbag itself and the gas generator. The gas generator is made in the form of a pyropatron with an igniter. When a frontal or side impact is of sufficient force to cause the ECU sensor contacts to close, current is supplied to the ignition circuit, resulting in the ignition of the squib cartridge and filling the airbag with gas.