Restraint System - Occupant Classification System (OCS)

Group:
ELECTRICAL

Number:
04-90-003

Date:
FEBRUARY, 2004

Model:
2004 ELANTRA

Subject:
OCCUPANT CLASSIFICATION SYSTEM (OCS)

DESCRIPTION:

The 2004 Elantra is the first Hyundai available that meets the advanced air bag requirements of Federal Motor Vehicle Safety Standard (FMVSS) 208 - Occupant Crash Protection. The amendment to the standard requires 20 percent of a manufacturer's vehicles sold in the United States manufactured between September 1, 2003 and September 1, 2004 to comply with NHTSA's Advanced Air Bag Rule. The percentage will increase to 65% during the following year and by September 1, 2006, all vehicles must comply. The advanced air bag requirement is a significant revision to the Standard, intended to reduce the risk of serious air bag induced injuries, particularly for small adults and young children.

The Occupant Classification System (OCS) complies with FMVSS 208 by detecting the presence of a passenger in the front passenger seat and automatically turning off the right side air bags for light weight or out-of-position occupants.

GENERAL INFORMATION:

^ The OCS is designed to detect the presence of a properly seated occupant (sitting upright with the seat in an upright position, centered on the seat cushion, with legs comfortably extended) and determine if the passenger's air bag and the passenger's side impact air bag should be enabled (may inflate) or not.

^ The Elantra OCS is a pattern and weight recognition sensor. The sensor not only estimates the weight, but also monitors the number of activated cells, makes calculations (based on size and location) and determines if the front passenger air bag should be enabled or not.

^ The OCS force sensor resistor (FSR) cells are located in the front passenger seat. The FSR's resistance values decrease with increasing activated cells. When a predetermined number of these cells have been detected, the Passenger Air bag (PAB) [including the Passenger Side Air bag (PSAB) and Passenger Side Seat Belt Pretensioner (PSBT)] circuitry is activated and the "PASSENGER AIR BAG OFF" lamp is turned off.

^ It is important to note that weight alone cannot be used as criterion for evaluating the functionality of the OCS. If the OCS senses the seat is occupied by someone of light weight or the passenger is out of position (taking his/her weight off of the seat for a period of time), the system will illuminate the "PASSENGER AIR BAG OFF" lamp.





^ When the passenger is seated in the proper position, the indicator lamp will turn off. A momentary illumination of the lamp with a passenger in the right front seat may indicate the system briefly sensed less weight in the seat than the specification or the passenger was temporarily out of position, and does not necessarily indicate a malfunction of the system.

^ For small stature adults, the passenger sensing system may turn off the passenger's frontal air bag, depending on the person's seating posture and body build. If this happens, turn the vehicle off, place the seat back in the full upright position, sit upright in the seat, centered on the seat cushion, with legs comfortably extended. Restart the vehicle and have the person remain in this position for about 30 seconds. This will allow the system to detect the person and enable the passenger's air bag.

^ The OCS lamp may illuminate for tall and light weight adults when their legs are pulled close to the cushion. The person should sit upright, not leaning or reclining and comfortably extending their legs to make contact to the seat cushion.

^ There may be a few seconds delay for the OCS light to turn on or off.

^ Temperature may slightly affect the seat material and sensing characteristics of the OCS.

^ Aftermarket equipment, such as seat covers, must not be used because it can affect how the OCS system operates.

NOTE:
1. Even if a vehicle is equipped with an OCS, do not install a child restraint system in the front passenger's seat. The rear seat is the safest place for children. Infant and child restraints must be properly installed in the rear seat according to their manufacturers' instructions to provide a safe ride for infants or small children.

2. Always wear seat belts when driving or riding in a motor vehicle.

3. The operation of driver's air bag and the driver's side impact air bag are not affected by the OCS.

4. Refer to the 2004 Elantra Owner's Manual section "Occupant Classification System" (Section 1 - pages 36-37) and TSB # 03-90-024 (2004 Elantra Supplemental Restraint System) for more details.