Seat Occupant Sensor: Service and Repair

Occupant Detection Sensor


To avoid serious or fatal injury on vehicles equipped with airbags, disable the Supplemental Restraint System (SRS) before attempting any steering wheel, steering column, airbag, seat belt tensioner, impact sensor or instrument panel component diagnosis or service. Disconnect and isolate the battery negative (ground) cable, then wait two minutes for the system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the SRS. Failure to take the proper precautions could result in accidental airbag deployment.


When handling a new Occupant Detection Sensor (ODS), it should never be bent, creased, torn, cut or abraded. The ODS should not be handled with or come into contact with hard or sharp-edged tools or objects. Do not allow the ODS to drop more than 2 meters (6.5 feet). Prior to installation, do not sit on, stand on or place boxes, tools or any other foreign object on the ODS. If the ODS adhesive patches become inadvertently adhered to any seat materials or foreign objects prior to proper positioning on the seat cushion, the ODS must be scrapped and replaced with a new unit. Do not modify the seat foam or trim materials of a seat that contains an ODS. Failure to observe these cautions may result in an inoperative ODS, or an ODS that provides inaccurate inputs to the Occupant Restraint Controller (ORC).

• The following procedure applies only to seats with a cut and sewn trim cover and no heater mat. In seats with a molded in place trim cover, the ODS can only be serviced by replacing the entire seat cushion foam and trim assembly. In seats with a cut and sewn trim cover and a heater mat, the ODS can only be serviced by replacing the entire seat cushion foam, ODS and heater mat unit.

Removal







- Position the passenger side front seat to its most forward position for easiest access to the front seat mounting hardware.

- Disconnect and isolate the battery negative cable. Wait two minutes for the system capacitor to discharge before further service.

- Remove the passenger side front seat from the vehicle.

- Remove the trim from the front seat cushion foam and frame.

- Reach under the back of the front seat cushion frame to access and disconnect the Occupant Detection Sensor (ODS) (1) pigtail wire connector from the seat wire harness.

- Disengage the two adhesive patches (2 and 3) of the ODS from the top surface of the seat cushion foam (4).

- Remove the ODS from the seat cushion.

Installation







- Mark the Center Line (CL) of the seat cushion on the top of the seat cushion foam.

- Measure and mark a transverse line (Distance A) on the top of the seat cushion foam 119 millimeters (4.68 inches) rearward from the back edge of the front crimp channel in the seat cushion foam (4).


The adhesive used to secure the ODS to the seat is heat activated and requires that both the adhesive and the material it is applied to be ideally between 21° and 38° C (between 70° and 100° F). Application of the ODS to surfaces below 10° C (50° F) is not recommended as the adhesive becomes too firm to readily adhere. Do not touch or allow the adhesive patches to contact any foreign materials with the release paper removed. Do not attempt to add adhesive materials to the ODS.

- Peel the release paper off of the front adhesive patch (2) on the underside of the Occupant Detection Sensor mat (1).

- Carefully position the ODS onto the seat cushion with the adhesive patches centered on the marked seat cushion center line and with the forward edge of the sensor mat aligned with the transverse line behind the front crimp channel.

- Apply hand pressure (0.8 bar or 12 psi) over the front adhesive patch of the ODS for at least four seconds to activate and adhere the adhesive to the seat cushion foam.

- Peel the release paper off of the rear adhesive patch (3) on the underside of the ODS mat.

- Apply hand pressure (0.8 bar or 12 psi) over the rear adhesive patch of the ODS for at least four seconds to activate and adhere the adhesive to the seat cushion foam.

- Route the ODS pigtail wires that exit the back of the hot melt block toward the back of the seat cushion foam.

- Reach under the back of the front seat cushion frame to access and reconnect the ODS pigtail wire connector to the seat wire harness.

- Reinstall the trim onto the front seat cushion foam and frame.

- Reinstall the passenger side front seat into the vehicle.

- Connect the battery negative cable.