Front Airbags

Front Airbags

Driver's airbag







Front passenger airbag







The airbags at the front of the car are:
- Driver's airbag, 2 stage deployment (introduced model year 2001).
- Driver's airbag 1 stage deployment (S80 1999-2000 model year only).
- Passenger airbag, 2 stage deployment (introduced model year 2001).
- Passenger airbag 1 stage deployment (S80 1999-2000 model year only).

1-stage deployment (model year 1999-2000)

The driver's airbag contains a pyrotechnical charge and igniter. At deployment the charge gives off a gas consisting mostly of hydrogen and carbon dioxide, which expands and fills the air bag. The passenger airbag uses a smaller amount of pyrotechnical charge (12 grams). This is connected to a holder containing Argon, helium and Oxygen. When the control module deploys the passenger airbag the pyrotechnical charge heats up the holder which detonates. A mixture of gases and powder charge fills the airbag.

2-stage deployment (model year 2001-)

The 2-stage system's deployment mechanism for the first stage is the same type as in the 1 stage system. Stage 2 in both the driver and passenger airbags contains a pyrotechnical charge. The front airbags have two ignition components, powder charges, in the airbags. The connections are electrically separated from each other.

This means that they have their own power supply and grounding points from the control module. Two outputs are required from the control module to the airbag, one to each ignition component of the airbag. This means that four pins are used on the control module. Two power supply pins and two ground pins. The function of the 2 stage deployment is to activate different speeds and duration of the inflation of the airbag, depending on how strong the collision pulse is. Both stages are carried at each deployment. In the event of a light collision there is a longer time delay between stage 1 and 2. In the event of a more serious collision there is a shorter time delay between stage 1 and 2. the front airbags are positioned above the glove compartment and in the steering wheel.

Each stage on the airbags and seat belt tensioners has an igniter. These igniters consist of two pins, a thin ignition wire and explosive powder. When the supplemental restraint system module (SRS) transmits a current pulse, the ignition wire heats up and ignites the explosive powder which in turn ignites a gas generator and deploys the airbag.

NOTE: Ohmmeters or similar must not be used when testing the airbags or seat belt tensioner. Disconnect the airbags or seat belt tensioners before testing. The airbags may accidentally deploy if this is not done. Which can result in very serious injury or death.