The electronic control module uses information from up front to

• Further shorten the amount of time which lapses between the impact and the point at which the belt tensioners are triggered. As a result, the belt straps are pulled tight at a very early stage - the high-performance belt tensioners fitted to the front seats and the outer seats in the rear can instantaneously retract up to 13 centimetres of loose belt strap, meaning occupants are firmly strapped into the optimal position within the passenger safety cell when the impact occurs and can be decelerated together with the bodywork structure as soon as possible.
• Control the front seat belt force limiters adaptively, according to the particular type of collision. This new technology allows the restraining force of the belt strap to be reduced progressively: should the sensors relay information indicating a severe frontal collision, the belt will first be pulled taut until it reaches maximum tension. The belt force limiters switch to a lower tension just a moment later - the extra slack in the belts allows occupants in the front to fall deeper into the airbags, and reduces the loads exerted on their chests.
• Trigger the driver's and front-passenger airbags not just earlier but in two stages, depending on the type of collision:
• Stage 1: in light frontal collisions, the electronics trigger just one chamber of the two-stage airbag gas generators. As a consequence, the airbags are deployed with a lower internal pressure.
• Stage 2: Should the control module detect a more severe frontal collision, five to fifteen milliseconds later it will also activate the second chamber of the gas generators. This inflates the airbags to a higher pressure and offers the occupants a level of protection adapted to the impact severity.