Dual-igniter airbag control switch

In a motor vehicle airbag system, having a module with a plurality of igniters for causing an airbag to inflate, the igniters each having an impedance of predetermined value, a multi-function vehicle system computer that monitors the status of the module and registers a fault if the impedance of the igniters in the module varies from the predetermined value, and first and second wires extending between each of the igniters and the vehicle system computer for conveying signals between the module and the vehicle system computer, the improvement comprising:

• a break in each of the first wires, interrupting continuity between the vehicle system computer and each of the igniters;
• a housing adapted to be mounted in a passenger compartment of the motor vehicle;
• a pair of leads for each of the first wires, the leads of each pair having ends connected to one of the first wires on opposite sides of the breaks, each pair of leads extending into the housing;
• a manually operable switch mounted in the housing and having a manual engagement actuator on an exterior of the housing, the switch having a pole for each igniter, each of the poles being connected to one of the leads of each of the pairs, each of the poles having an on position that connects the leads of each of the pairs together for providing continuity between the vehicle system computer and each of the igniters, each of the poles having an off position that breaks the connection between the leads of each of the pairs;
• a resistor mounted in the housing for each of the igniters, each of the resistors being electrically connected to each of the second wires and connected to the switch, so that while in an off position, the poles place the resistors in a series between the first and second wires and the vehicle system computer, each of the resistors having an impedance similar to that of one of the igniters so as to avoid the register of a fault by the vehicle system computer while the switch is in the off position.

A method of preventing the registering of a fault signal in a vehicle system computer controlling airbag deployment of a motor vehicle airbag system, the airbag system including a module with a plurality of igniters for causing an airbag to inflate, the vehicle system computer monitoring the status of the module and registering a fault signal if the impedance of the igniters in the module varies from the predetermined value, and first and second wires extending between each of the igniters and the vehicle system computer for conveying signals between the module and the vehicle system computer, the method comprising:

• severing each of the first wires between the igniters and the vehicle system computer, creating a pair of ends for each of the first wires;
• connecting a portion of a manually operable switch between the ends of each of the first wires;
• connecting one side of a resistor to each of the second wires and the other side to the switch, each of the resistors having an impedance similar to that of one of the igniters;
• placing the switch in an on position, providing continuity in the first wires between the vehicle system computer and each of the igniters;
• then
• placing the switch in an off position, breaking continuity in the first wires between the vehicle system computer and each of the igniters and simultaneously placing the resistors in series between the first and second wires and the vehicle system computer, each of the resistors having an impedance similar to that of one of the igniters, so as to prevent the vehicle system computer from registering a fault signal by providing impedance with the predetermined value while the switch is in the off position.