Module, Occupant Classification: Description: Description
The passenger seat for this vehicle incorporates the Occupant Classification System (OCS). The OCS consists of a single factory-calibrated unit, which includes the following components:
- Electronic Pressure Sensor - The electronic pressure sensor is integral and internal to the Occupant Classification Module (OCM). Only the hose nipple for the pressure hose is visible on the outside of the OCM housing. The remainder of the sensor and the sensor circuitry are concealed and protected within the molded black plastic OCM housing.
- Occupant Classification Module
- The Occupant Classification Module (OCM) (4) is located beneath the front of the passenger seat cushion. Concealed within a hollow in the center of the molded black plastic OCM housing is the electronic circuitry of the module. The module housing is sealed to enclose and protect the internal electronic circuitry. A connector receptacle integral to the OCM housing contains terminal pins that connect the sensor to the vehicle electrical system through a dedicated take out and connector of the passenger seat wire harness. A hose nipple formation is integral to the OCM housing.
A slot integral to the OCM housing snaps over a blade on a stamped metal bracket riveted to the forward inboard underside of the seat cushion pan.
- Pressure Hose - Beneath the seat cushion a length of clear poly hose serves as the OCS pressure hose (3). The hose is securely clamped at one end to a hose nipple fitting that extends downward from the Seat Weight Sensor (SWS) (also known as the seat weight bladder), and at the opposite end to the hose nipple formation of the electronic pressure sensor integral to the outside of the OCM housing. The pressure sensor circuitry is internal and integral to the OCM. The pressure hose is filled with the same silicone fluid that fills the SWS.
- Seat Cushion Foam - The passenger front seat cushion foam is an integral part of the factory-calibrated OCS.
- Seat Weight Sensor
- The Seat Weight Sensor (SWS) (also known as the seat weight bladder) (1) is located between the seat cushion pan and the seat cushion foam. A protective plastic liner is installed between the lower surface of the bladder and the seat cushion pan, and another is installed between the upper surface of the bladder and the seat cushion foam. The bladder and both liners are secured near the forward end to the seat cushion pan by two plastic push-in fasteners (2).
The bladder consists of two sheets of an elastomeric material and a molded plastic hose nipple fitting. The two sheets of elastomeric material are sealed together around their perimeter and joined at numerous specific intervals within their field. The hose nipple fitting is sealed to a small round hole in the lower surface of the bladder and is pointed downward where it passes through a clearance hole in the liner and extends to just below the seat cushion pan. The bladder is filled with a silicone fluid to become a pliable, quilted, resistive mat and is connected to a pressure hose that connects it to the electronic pressure sensor within the OCM unit.
All of the components that make up the OCS are a factory-calibrated and assembled unit. The OCS components cannot be adjusted or repaired and, if damaged or ineffective, they must be replaced as a calibrated unit. Any time the OCS is removed or replaced for any reason, the new OCS data must be configured within the Occupant Restraint Controller (ORC) using a diagnostic scan tool. Refer to the appropriate diagnostic information.