Pic. 1.123. Deployment of the seat belt in an emergency
Under normal conditions, a pretensioner seat belt works in the same way as a standard locking belt (E.L.R). (In the event of sudden braking of the vehicle, the belt will be blocked. It will also be blocked if the passenger leans forward sharply.) However, in the event of a moderate to severe frontal impact, the pretensioner will instantly retract the seat belt. This helps to clearly fix the passenger with the seat belt and reduce the distance between them.
Pic. 1.124. System of seat belts with a pretensioner: 1 – control lamp SRS; 2 - seat belt pretensioner assembly; 3 - electronic control unit SRS
The system of seat belts with a pretensioner consists of the components shown in figure 1.124.
Note. When the seat belt pretensioners deploy, a small amount of smoke is emitted and a strong bang occurs. These phenomena are normal and not dangerous. Although this smoke is not poisonous, it should not be inhaled as it may cause irritation or coughing. Wash your face and hands thoroughly after deploying the seat belt pretensioners.
Attention! After turning the ignition key to position «ON» («On») control lamp of additional system of passive safety SRS (airbags) flashes for about 6 seconds and then turns off. This is due to the fact that the sensor that activates the SRS airbags is included in the seat belt pretensioner circuit.
Attention! This lamp also illuminates if the pretensioner seat belt is defective.
Seat belt pretensioners are designed for single use. After deployment, the seat belt pretensioners are replaced. All seat belts must be replaced after a traffic accident (accidents), regardless of the type of seat belt.
Attention! After the pretensioner assembly is deployed, some parts of the pretensioner will be hot. Do not touch them for several minutes.
Attention! Do not attempt to test or replace pretensioner seat belt mechanisms yourself.
Attention! Do not hit the seat belt pretensioners. Do not attempt to service or repair the pretensioner seat belt system yourself.