Circuit/System Description
The inflatable restraint sensing and diagnostic module (SDM) sends the status of the driver seat belt switch via serial data to the instrument panel cluster (IPC). After receiving the message, the IPC controls the illumination of the driver seat belt indicator.
The seat belt buckle switch is located within the seat belt buckle assembly and provides an input to the inflatable restraint sensing and diagnostic module (SDM). The SDM supplies a low reference circuit and a seat belt switch signal circuit to determine a buckled or unbuckled condition.
If the SDM determines the passenger is sitting in the passenger seat and the seat belt has not been buckled, the SDM will send a serial data message to the instrument panel cluster (IPC) to illuminate the seat belt warning indicator. Then the IPC sends a ground signal to the inflatable restraint I/P module indicator to illuminate the passenger seat belt warning indicator.