MRS III Principle of Operation

As with previous MRS systems, the triggering thresholds are programmed in the MRS III control module. These thresholds are determined by BMW through crash and vehicle testing during the design and development of the vehicle. These thresholds will vary depending on the vehicle type.

There are several different thresholds for airbag and safety restraint deployment:

• Belt pre-tensioner threshold for activation of the seat belt tensioners.
• Airbag threshold #1 - the first level of activation for the two stage front airbags, always deployed first when the front triggering threshold is reached.
• Airbag threshold #2 - the second level of the two stage front airbags, can be deployed simultaneously or after a time delay, depending on the severity of the impact.
• Rear crash threshold - for activation of the seatbelt tensioners with a rear impact.
• Battery safety terminal threshold - for activation of the BST with airbag deployment.
• Side airbag/ITS threshold - for deployment of the side and thorax airbags.