Arming Sensor/Dual Pole Arming Sensor

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 1995 GMC Vandura Special, 1995 GMC Vandura, 1995 GMC Rally Camper Special, 1995 GMC Rally, and 1995 Chevrolet Sportvan. However, it is still accessible from the selected car via links, so may be relevant.

Arming sensor/dual pole arming sensor is a protective switch located in power feed side (positive side) of deployment loop. It is calibrated to close at low-level velocity changes (lower than discriminating sensors). This assures that each inflator module is connected directly to 36VLR output of DERM or ignition voltage when either of the discriminating sensors close.

Arming sensor/dual pole arming sensor consists of a sensing element, normally open switch contacts, a diagnostic resistor, and 2 diodes. Sensing element closes switch contacts when velocity of vehicle changes at a rate indicating potential need for deployment. A diagnostic resistor is connected in parallel with normally open switch contacts and allows for a small amount of current flow through deployment loop during normal undeployed conditions. This small current flow results in voltage drops across each component within loop.

DERM monitors these voltage drops to detect circuit or component faults. The 2 diodes provide isolation between 36VLR output of DERM and ignition voltage. In some vehicles, arming sensor is combined with passenger compartment discriminating sensor.