Magnum SRT-8 V8-6.1L VIN 3 (2006)
Seat Occupant Sensor: Description and Operation
SEAT WEIGHT SENSOR
DESCRIPTION
The seat weight sensors (4) are strain gauge-type units. The electronic elements of the sensor are encased in a potting material within the molded plastic
sensor housing. Four sensors (4) are used in the Occupant Classification System (OCS). A sensor is located at each corner of the passenger side front
seat.
The strain gauge for each sensor is secured by three screws and nuts (2) between the seat cushion frame and the seat adjusters (3). A molded connector
receptacle (1) integral to each sensor housing is connected to the vehicle electrical system through a dedicated connector and take out of the passenger
seat wire harness beneath the seat cushion frame.
The seat weight sensors cannot be adjusted or repaired and, if faulty or damaged, the entire sensor must be replaced.
WARNING:
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THE SEAT WEIGHT SENSOR IS A SENSITIVE, CALIBRATED UNIT AND MUST BE HANDLED CAREFULLY. DO NOT DROP
OR HANDLE ROUGHLY. IF DROPPED OR DAMAGED, REPLACE WITH ANOTHER SENSOR. FAILURE TO DO SO MAY
RESULT OCCUPANT INJURY OR DEATH.
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THE FRONT PASSENGER SEAT MUST BE HANDLED CAREFULLY AS WELL. WHEN REMOVING THE SEAT, BE CAREFUL
WHEN SETTING ON FLOOR NOT TO DROP. IF DROPPED, THE SENSOR MAY BE INOPERATIVE, COULD RESULT IN
OCCUPANT INJURY, OR POSSIBLY DEATH.
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WHEN THE SEAT IS ON THE FLOOR, NO ONE SHOULD SIT IN THE FRONT PASSENGER SEAT. THIS UNEVEN FORCE MAY
DAMAGE THE SENSING ABILITY OF THE SEAT WEIGHT SENSORS. IF SAT ON AND DAMAGED, THE SENSOR MAY
INOPERATIVE, COULD RESULT IN OCCUPANT INJURY, OR POSSIBLY DEATH.
OPERATION
The seat weight sensor units are designed to sense the relative weight of a load applied to the passenger side front seat, which provides a logic input to
the microprocessor of the Occupant Classification Module (OCM). When a load is applied to the seat, the strain gauge of each sensor is flexed causing a
change of electrical resistance through the strain gauge. These changes in resistance are measured by the sensor and the internal sensor circuitry changes
the sensor output voltage.
Each weight sensor receives a nominal five volts and a ground through parallel hard wired circuits from the OCM. The OCM then monitors the output
voltage of each sensor on dedicated hard wired data communication circuits. The hard wired circuits between the sensors and the OCM may be
diagnosed and tested using conventional diagnostic tools and procedures. However, the most reliable, efficient, and accurate means to diagnose the seat
weight sensor inputs to the OCM, and the electronic message communication between the OCM and the Occupant Restraint Controller (ORC) requires
the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.
