Firing Strategies

The seatbelt pretensioners are fired when the pretensioner impact limit is exceeded. The Restraints Control Module (RCM) only fires the pretensioners if the related seatbelt is fastened.

The driver and passenger airbags are only fired in a frontal impact. For passenger airbags, if an impact exceeds the limit, the inflators are fired.

On North American Specification (NAS) vehicles, the passenger airbag is disabled unless the front row passenger seat is occupied by a large person. In all markets except NAS, the passenger airbag can be selected off in the vehicle set-up menu of the Instrument Cluster (IC).

On NAS vehicles, the load limiter actuator, is fired if the front impact threshold is exceeded and the passenger seat is forward of the seat position sensor switching point.

If there is a fault with a seatbelt buckle switch, the RCM assumes the related seatbelt is fastened for the pretensioner firing strategy and unfastened for the driver and passenger airbag firing strategies. If there is a fault with the occupant classification sensor, the RCM disables the passenger airbag. If there is a fault with the passenger airbag deactivation switch, the RCM disables the passenger airbag.

If a side impact limit is exceeded, the RCM fires the side airbag and the side air curtain on the appropriate side of the vehicle. If the side impact limit on the front passenger side of the vehicle is exceeded, the RCM also evaluates the input from the occupant classification sensor. The side airbag is fired only if the front passenger seat is occupied by a large person (NAS only).

If multiple impacts occur, after responding to the primary impact the RCM will output the appropriate fire signals in response to any further impacts if unfired units are available.