Seat Occupant Sensor: Description and Operation

OCCUPANT CLASSIFICATION SENSOR

CAUTION:
- It is necessary to rezero the OCS system when a front passenger seat cushion is disassembled, a new trim cover installed, or an OCS service kit is installed. A diagnostic tool is used to trigger the active command to carry out rezeroing of the OCS system.
- Make sure the seat is completely assembled before rezeroing.
- The following precautions must be taken before rezeroing of the OCS system.
- Make sure the OCS system components are connected and no faults are present.
- Make sure the OCS system is not at a temperature below 0°C (32°F) or above 45°C (113°F) when initiating the rezeroing process. If the vehicle has been exposed to extreme cold or hot temperatures, the vehicle must be exposed and kept at a temperature within the limits, 0°C to 45°C (32°F to 113°F) for a minimum of 30 minutes.
- Make sure nothing is present on the passenger seat before rezeroing and nothing is placed on the seat during the rezeroing process.
- Make sure a minimum 8-second time period has passed after cycling the ignition switch ON before the rezeroing process.

NOTE:
- For best results in rezeroing, the OCS system should be at or near room temperature, 10°C to 29°C (50°F to 85°F).
- To identify between a production OCS system and a OCS system service kit, inspect the OCS ECU electrical connector.

A production OCS system allows disconnection of the electrical connector from the OCS electronic control unit (ECU).

An OCS system service kit (OCS service kit) has the OCS ECU electrical connector glued to the ECU, it cannot and should not be disconnected or altered. An OCS system service kit also has an in-line 10-pin connector between the OCS ECU and the seat wiring harness.

- If the first attempt to rezero the OCS system is unsuccessful, a second attempt must be made.

The seat OCS is found only on the front passenger seat. The front passenger seat OCS system is comprised of a silicone gel-filled bladder mounted in the seat cushion, a pressure sensor that is mounted to the seat frame and an electronic control unit which is also mounted to the seat frame. Pressure is applied to the OCS bladder when weight of any occupant or object in the front passenger seat is present. The pressure is then transferred through a tube, is sensed by the OCS pressure sensor, then electronically communicated to the OCS electronic control unit. Based on programmed limits, the OCS electronic control unit will inform the RCM, via the HS-CAN, of the necessary information. The RCM uses this information in determining if the passenger air bag module or passenger seat side air bag module is to be deployed in the event of a deployable collision. The OCS system components (seat pan, seat cushion foam pad, bladder with pressure sensor and electronic control unit) are calibrated to each other and are serviced as an assembly. OCS system components are not to be installed separately. If installing a new OCS system, OCS system component or seat cushion foam pad, a new OCS system service kit (seat pan, seat cushion foam pad, bladder with pressure sensor and electronic control unit) must be installed as an assembly.

The OCS system, if equipped, is also used for operation of the passenger Belt Minder. To deactivate or reactive the passenger Belt Minder feature, refer to Instrument Panel, Gauges and Warning Indicators or the owner's literature.