Audi A4 Owners Manual
Description of airbag system
General notes on airbag system
The airbag is an integral part of the car's passive safety system.
In conjunction with the three-point seat belts, the airbag system gives the front occupants additional protection for the head and chest in the event of a severe frontal collision.
In a severe side collision the side airbags and the head-protection airbags reduce the risk of injury to the occupants in the areas of the body facing the impact ⇒ .
In addition to their normal function of protecting the occupants in a collision, the seat belts also hold them in a position where the airbags can inflate properly and provide maximum protection.
The airbag system will only work with the ignition on. The airbag system is monitored electronically; the airbag warning lamp indicates whether the system is functioning properly.
The main parts of the airbag system are:
- the electronic monitoring system (control unit and sensors),
- the two front airbags,
- the front side airbags, the side airbags on the outer rear seats* and the head-protection airbags,
- the airbag warning lamp in the instrument cluster.
There is a fault in the airbag system if the warning lamp
- does not come on when the ignition is switched on,
- does not go out about 4 seconds after the ignition is switched on,
- goes out and then comes on again after the ignition is switched on,
- comes on or flickers while the car is moving.
- The airbags are not a substitute for the seat belts; they are an integral part of the car's overall passive safety system. The airbags can only offer effective protection if the occupants are wearing their seat belts. For this reason it is very important to wear the seat belts at all timesgggggg 194, Why is it so important to use seat belts?.
- The seat belts and airbags can only provide maximum protection if the occupants are seated correctly, Seats and storage.
- If you do not wear a seat belt, if you lean forward, or are not seated correctly while the vehicle is in motion, you are at greater risk of injury should the airbag system be triggered in an accident.
- Components of the airbag system are located in various parts of the vehicle. If repairs to other vehicle components make it necessary to perform work on the airbag system or to remove or install parts of the airbag system, this may cause damage to the airbag system. As a result, the airbags may not inflate correctly or may not be triggered at all in an accident situation. For this reason, you should always have the work carried out by a qualified workshop.
- If a fault should occur in the airbag system, have the system checked immediately by a qualified workshop. Otherwise the system may fail to trigger in an accident.
- Do not attempt to modify components of the airbag system in any way.
- Never make any alterations to the front bumper or the body.
- Do not remove the front seats.
- The airbag system can only be activated once; if the airbag has been triggered, the system must be replaced. Should the airbag system or airbag modules have to be replaced, the qualified workshop carrying out the replacement will document all details in the appropriate section of the Service Schedule.
- If you sell the vehicle, please remember to pass on the complete Service Wallet to the new owner. If any of the airbags have been deactivated, it is important that the new owner is also given the relevant documents.
- The relevant safety requirements must be observed when the vehicle or components of the airbag or belt tensioner systems are scrapped.
- In an accident in which one or more airbags are triggered the alternator
and the starter are - for safety reasons - both disconnected from the battery
via a pyrotechnic circuit breaker.
− Any repairs to the pyrotechnic circuit breaker must always be performed by a qualified workshop (accident risk).
− The relevant safety requirements must be observed when the vehicle or the circuit breaker are scrapped.
When are the airbags triggered?
The airbag system is triggered in collisions with a severe impact.
The airbag system is designed so that the airbags for the driver and front passenger are triggered in a severe frontal collision.
In severe side collisions the side airbags on the impact side of the vehicle are triggered together with the head-protection airbag.
The front airbags, side airbags and one of the head-protection airbags may be triggered together in certain types of accident.
The airbag system is not triggered in minor frontal or side collisions, or in rear collisions or if the car overturns. In these situations the occupants are protected by wearing the seat belts.
Factors determining the triggering response
It is not possible to define the exact triggering response of the airbag system in all possible situations, since the circumstances in different types of accident will vary considerably. Important factors include, for example, the nature (hard or soft) of the object which the car hits, the angle of impact, vehicle speed and so on.
Whether the airbags are triggered depends primarily on the vehicle deceleration rate resulting from the collision. By processing the signals from the sensors located in the vehicle, the electronic control unit is immediately able to evaluate the severity of the collision and activate the restraint systems accordingly. If the deceleration rate is below the predefined reference value in the control unit the airbags will not be triggered, even though the accident may cause extensive damage to the car.
The airbag releases a fine dust when it inflates. This is quite normal and does not mean there is a fire in the vehicle.