Arming Sensor

The Arming Sensor and the Passenger Compartment Discriminating Sensor are housed in the Dual Sensor. Although both sensors require replacement as an assembly, they are referred to independently.
Located behind the right hand side of the instrument panel, the Arming Sensor is a protective switch in the deployment loop's power feed side (high side). The Arming Sensor is calibrated to close at low level velocity changes (lower than the Discriminating Sensors). This assures that the Inflator Module is connected directly to the DERM's 36 VLR output or "IGNITION 1" voltage when either Discriminating Sensor closes.
The Arming Sensor consists of a sensing element, normally open switch contacts, a diagnostic resistor and two steering diodes. The sensing element closes the normally open switch contacts when the vehicle velocity changes at a rate that indicates potential need for deployment.
The diagnostic resistor is connected in parallel with the normally open switch contacts and allows a small amount of current through the deployment loop during normal non-deployment conditions. This small current flow results in voltage drops across each component within the loop. The DERM monitors these voltage drops to detect circuit or component faults. The two steering diodes provide isolation between the 36 VLR output of the DERM and "IGNITION 1" voltage.