Sensor, Occupant Detection: Operation

The Occupant Detection Sensor (ODS) acts as a simple switch to detect loads placed upon the seat cushion on which it is installed. The sensor circuits are connected to and monitored by the Occupant Restraint Controller (ORC) whenever the status of the ignition switch is ON. The ORC uses an algorithm logic in monitoring the changing states of the sensor input to determine whether the seat cushion load is static or dynamic.

The ORC micro-controller continuously monitors all of the Supplemental Restraint System (SRS) electrical circuits to determine the system status and readiness. If the ORC detects a monitored system fault, it sets a Diagnostic Trouble Code (DTC). However, because the passenger ODS input is only used for control of the passenger belt alert feature, it has no effect on SRS component features or functions. The airbag indicator is NOT  illuminated in response to a detected ODS circuit fault. In diesel engine equipped models, the driver ODS is used only as a signal indicating whether or not the drive is physically in the driver seat. When the driver leaves the driver seat, the ODS sends a signal to the ORC, which in turn sends a CAN bus message to the Antilock Brake System module to actuate the Electronic Parking Brake (EPB).

The ODS receives source current and a clean ground through dedicated sensor plus and minus circuits from the ORC. The ORC then sends the appropriate sensor status information over the Controller Area Network (CAN) data bus to the Instrument Panel Cluster (IPC), which uses this information as an additional logic input used for control of the seat belt indicator and the passenger belt alert feature.

The hard-wired circuits between the ODS and the ORC may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the ODS or the electronic controls and communication between other modules and devices that provide some features of the passenger belt alert feature. The most reliable, efficient and accurate means to diagnose the ODS or the electronic controls and communication related to the passenger belt alert feature operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.