Occupant Detection Sensor (ODS)

DESCRIPTION 

Courtesy of CHRYSLER GROUP, LLC

An Occupant Detection Sensor (ODS) is standard equipment in this vehicle. There may be up to three sensors in the vehicle, depending on seating configuration. There is one ODS located directly below the passenger side seat cushion trim cover in every seating configuration. In models equipped with an optional passenger bench seat, there is another ODS located directly below the center seating position of the seat cushion trim cover. In models that are equipped with a diesel engine, there is another ODS located directly below the driver side seat cushion trim cover. The two passenger sensors provide information to the Occupant Restraint Controller (ORC) used for control of the passenger belt alert feature. The driver sensor provides information to the ORC used for control of the Electronic Parking Brake (EPB).

Each ODS consists of a flexible clear plastic sensor mat containing several resistive membrane, force sensing resistor cells that is secured by an adhesive strip to the top surface of the seat cushion foam. The adhesive patch on the ODS is a one time only material and cannot be reactivated or reused if removed.

A short, two-conductor pigtail wire and connector connect the sensor to the vehicle electrical system through a dedicated take out and connector of the seat wire harness. A hot melt adhesive block encapsulates and protects the connections between the electrical conductors in the tail of the sensor mat and the pigtail wires as well as a diagnostic resistor.

The ODS cannot be adjusted or repaired, and must be replaced if damaged or ineffective.

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 microcontroller 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 hardwired 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.