Side Impacts

The driver and passenger side (thorax) airbags and the advanced head protection system (AHPS2) airbags are deployed in the event of a side impact of sufficient severity which exceeds the side impact trigger threshold of the side impact crash sensors. When the MRS control unit receives a signal from one of the side impact crash sensors in conjunction with the internal main sensor, the control unit activates the side (thorax) airbag and the AHPS2 airbag on the side of the vehicle suffering the impact [also with a separate threshold the BST. The main sensor works as a "safing sensor" it must confirm the side impact request by the side sensors to deploy the airbags.

A current from the control unit triggers the module to ignite a small quantity of nitrocellulose to generate nitrogen gas. The expanding nitrogen gas punctures a pressurized argon and nitrogen gas chamber, the released gas mixes with the gas released from the nitrocellulose chamber and the combined gas expands causing airbag inflation. The inflating side (thorax) airbag bursts out of the seat cover at the outboard piping and pushes the seat occupant away from the impact force. At the same time, the AHPS2 airbag module is deployed using a similar deployment method; as the AHPS2 airbag expands it breaks out from beneath the headlining trim to protect the occupant(s) from head injuries.

When fully deployed, the side airbags offer additional protection to the front seat occupants in the event of a collision acting on the side of the vehicle. Either the driver's side airbag circuit or the passenger's side airbag circuit is activated depending on the side of the vehicle suffering the impact. After the airbags have fully inflated, the airbags progressively deflate the gas from vent holes to reduce the risk of injuries. The AHPS2 airbag deflates at a slower rate than for front and side (thorax) airbags, this is to provide additional head protection in the event of a secondary impact.