When the sensors detect a moderate-tosevere side impact, the control unit signals the side airbag on the impact side to immediately inflate.

When a side airbag deploys with little or no visible damage

Because the airbag system senses sudden acceleration, a strong impact to the side of the vehicle's framework can cause a side airbag to deploy. In such cases, there may be little or no damage, but the side impact sensors detected a severe enough impact to deploy the airbag.

When a side airbag may not deploy, even though visible damage appears severe

It is possible for a side airbag to not deploy during an impact that results in apparently severe damage. This can occur when the point of impact was towards the far front or rear of the vehicle, or when the vehicle's crushable body parts absorbed most of the crash energy. In either case, the side airbag would not have been needed nor provided protection even if it had deployed.