Theory Of Operation

WARNING: This page is about a different car, the 2013 RAM 3500 HD and 2013 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

The Occupant Detection Sensor (ODS) is a electrical resistance mat with cells that is located in the front passenger seat. This sensor is only used for passenger seatbelt reminder. The seat sensor assumes a passenger is present when a minimum of 103 pounds (47kg) of weight is placed in the seat the resistance will show 214 ohms. When a package or no person is occupying the passenger seat the resistance range will be between 701 and 1.5k ohms. The resistance of the mat decreases, signaling to the ORC module that a passenger is present. The ORC then transmits this information to the instrument cluster over the CAN bus. The passenger is only reminded to buckle up if the passenger seat occupant minimum weight threshold determined by the ODS is surpassed and the seat belt buckle is still not latched. The ODS receives battery voltage and clean ground through dedicated sensor plus and minus circuits from the ORC. The ORC receives, processes, and continuously monitors (monitor rate of 500 ms) the analog signal from the ODS. The ODS component is not repairable, if determined inoperable, it would require to be replaced with a new component. The seatbelt warning lamp will not set for this fault.