Description of Function of Airbag with Seat Belt Tensioner F. - Control Device - ra9100140f600x(0600)
Model 140
General
The risk of injury to the head and chest in the case of serious frontal collisions is further reduced by means of the driver's/front passenger's airbag unit in combination with the three-point seat belt and the energy-absorbing covers on the driver's and/or front passenger's side.
The driver's and front passenger's airbag units are marked "SRS Airbag". The warning light is marked SRS (Supplemental Restraint System).
Both systems are activated electrically by means of a control device in the event of a moderate to serious frontal collision. Our present knowledge indicates that, if undamaged, the entire airbag and seat belt tensioner restraint system should have a fully operational life of at least ten years. In contrast to the three-point seat belt, which only offers protection when worn, the vehicle occupant cannot influence the protection afforded by the airbag and seat belt tensioner system in any way. A properly worn three-point seat belt and the driver's airbag and front passenger's seat belt tensioner system are essential if this increased protection is to be fully effective.
The airbag and seat belt tensioner restraint system offers increased protection in the event of a frontal collision only. No protection at all is offered to a vehicle occupant not wearing a three-point seat belt in the event of a side collision, rear collision or roll-over.
Driver's Airbag
Driver's/Front Passenger's Airbag
Driver's Airbag USA Version
Driver's/Front Passenger's Airbag USA Version
Arrangement of Components
Driver's Airbag with Seat Belt Tensioners
Arrangement of Components
Driver's/Front Passenger's Airbag with Seat Belt Tensioners
Stick-on Label for Replacement Date of the Driver's Airbag Unit
The stick-on label with the replacement date of the airbag unit is located on the left-hand center pillar below the belt fastener.
Stick-on Label for Replacement Date of the Driver's/Front Passenger's Airbag Unit
On the left-hand center pillar below the belt fastener there is a stick-on label with the replacement date of the driver's and front passenger's airbag unit. The replacement date refers to the entire driver's and front passenger's airbag unit in each case. The operating life is at least ten years.
Driving with the Airbag and Belt Tensioner Restraint System
When the ignition key is in position "1", the red warning light with the "SRS" symbol in the instrument cluster should light up.
The warning light shows that the airbag and seat belt restraint system is in proper working order. In ignition key position "1" it should light up for approx. 4 secs and then go out again. If it fails to light up or to go out after the stated time, there is a fault in the system. The error time is recorded by the control device (N2/2) and can be read out afterwards.
Should an error be indicated in the above-mentioned way, the entire system must be checked as exhaustively as possible by trained staff via impulse output.
The operation of the standard-fitted driver's and front passenger's seat belts is not impaired by such a fault.
The complete airbag and seat tensioner restraint system consists of the following components:
- Driver's airbag unit
- Front passenger's airbag unit
- Seat belt tensioner unit
- Control device
- Warning light
- Energy-absorbing cover under dashboard (driver's and front passenger's side)
F. Control Device
The control device, also known as the trigger device or crash sensor, has the function of determining the seriousness of an accident, and, if necessary, activating the restraint system in good time.
General
The airbag restraint system has a control device with an integrated capacitator and a voltage transformer.
12-pin driver's airbag control device (N2/2)
16-pin front passenger's airbag control device (N2/2)
Function
The control device processes vehicle deceleration during frontal collision and is therefore rigidly mounted on a console on the vehicle transmission tunnel. A built-in safety switch, which interrupts the ignition circuits of the driver's airbag and the seat belt tensioner restraint system during normal driving operation, ensures that the airbag and seat belt tensioner can only be activated by actual acceleration. In this way it is possible to prevent malfunctions.
An acceleration pick-up, built into the control device, records the longitudinal deceleration effects on the vehicle and transmits a signal, which is suitably processed and passed onto the threshold value switches for evaluation.
When the preset activation thresholds of the two threshold value switches are exceeded, the final phases are switched through in accordance with the statuses called up via the seat belt lock switches (lock tongue in seat belt lock or not in seat belt lock). This causes activation (see table). If the power supply is interrupted during an accident, the driver's airbag can still be activated within 100 milliseconds, but not the two seat belt tensioners. In the case of vehicle voltage amounting to longer than 10 secs < 9.5 V, the warning light lights up and goes out at voltages of > 10 V.
The housing and the electrical connections are designed in such a way that malfunctions resulting from electrical interference in the vehicle electricity supply, caused by the switching on of electrical consuming devices and electromagnetic radiation on public highways can be one hundred percent excluded. New seat belt locks with separate switches and resistors are necessary to find out whether the lock tongues are inserted in the seat belt locks or not. This results in the following activation logic.
| Control Device | Driver's Seat Lock tongue | Front Passenger's Seat Lock tongue | |||
|---|---|---|---|---|---|
| not inserted | inserted | not inserted | inserted | ||
| 1st activation threshold exceeded | Seat belt tensioner | is not activated | is activated | is not activated | is activated |
| Driver's airbag | is activated | is not activated | |||
| 2nd activation threshold exceeded | Driver's airbag | has already been activated | is activated | ||
Explanation
In the case of a minor accident in which the protection afforded by the seat belts is sufficient, only the seat belt tensioners are activated when the 1st activation threshold is exceeded and the lock tongue is inserted in the seat belt lock.
If the lock tongues are not inserted in the seat belt locks, the driver's airbag is activated.
| Control Device | Driver's Seat Lock tongue | Front Passenger's Seat Lock tongue | ||||
|---|---|---|---|---|---|---|
| not inserted | inserted | Resistance front passenger's airbag | not inserted | inserted | ||
| 1st activation threshold exceeded | Seat belt tensioner | is not activated | is activated | simulates a constantly occupied driver's seat | is not activated | is activated |
| Driver's/ front passenger's airbag | is activated | is not activated | is activated | is not activated | ||
| 2nd activation threshold exceeded | Driver's and/or front passenger's airbag | has already been activated | is activated | has already been activated | is activated | |
Explanation
In the case of a minor accident, in which the protection afforded by the seat belts is sufficient, only the seat belt tensioners are activated when the 1st activation threshold is exceeded and the lock tongue is inserted in the seat belt lock. If the lock tongues are not inserted in the seat belt locks, the driver's and/or front passenger's airbag is activated.
When the 2nd activation threshold is exceeded, the driver's and/or front passenger's airbag is activated even if the lock tongue is inserted.
Modular Diagram of the Entire Function of the Driver's/Front Passenger's Airbag/Seat Belt Tensioner