The SRS consists of: an airbag on the driver's side, located in the center of the steering wheel and containing a folded cushion and gas generator unit; an airbox on the passenger side, located in the instrument panel and containing a rolled-up airbag and a gas generator unit; side air chambers located in the backs of the driver and front passenger and containing folded pillows and a gas generator unit. The SRSCM control unit is located on the floor of the vehicle and controls the airbag system and includes: an accelerometer that detects vehicle deceleration; spiral wire (spring), located in the steering column; electrical circuits and connectors. The coiled wire transmits the signal regardless of the position of the steering wheel.
The SRSCM determines the moment of collision based on information from the accelerometer, which constantly monitors the vehicle's acceleration.
The pyrotechnic gas generator converts the control electrical signal into an ignition signal, causing the powder to decompose, inflating the airbag bag.
Only specially trained personnel should be allowed to service airbags or SRS components. When servicing the SRS, extreme care must be taken to avoid personal injury from unauthorized deployment of driver or front passenger airbags.
Precautionary measures
Failure to properly deactivate or service the airbag system could result in unauthorized airbag deployment and serious injury. Also, improper maintenance of the airbag system may result in the airbag not deploying in a collision.
Before performing any maintenance, including removing or installing system components, carefully follow these guidelines.
1. Before servicing the airbag system, make sure that at least 30 seconds have passed after the ignition is turned off and the wire is disconnected from the negative terminal of the battery. The airbag system is equipped with an emergency power source that allows the airbags to deploy if the battery wires are disconnected in an accident. The time during which the emergency power supply powers the airbag system is 150 ms.
2. When the wire is disconnected from the negative terminal of the battery, the memory of the clock and sound systems is erased. Extract information from the sound systems before you begin. After completing the work, set the time on the clock and re-install the sound systems.
3. Signs of an airbag system failure are difficult to check, so diagnostic codes become the most important source of information when troubleshooting.
4. When troubleshooting the airbag system, check the stored fault codes before disconnecting the battery.
5. Do not use spare airbag parts from other cars.
6. Do not disassemble or repair airbag system components.
7. If any SRS component has been dropped or has cracks, dents, or other defects in the housing, bracket, or connector, replace them with new ones.
8. After carrying out the work, check the airbag system.
In some cases, the airbag warning light circuit may be broken by another circuit malfunction. Therefore, if the airbag warning light stays on, check that all DTCs have been cleared from memory.
9. When carrying out electric welding, be sure to disconnect the wire from the negative terminal of the battery.