Seat Belt Tension Sensor: Description and Operation

Belt Tension Sensor:

Belt Tension Sensor Location:

Vehicles equipped with the Occupant Classification System (OCS) include a belt tension sensor. This sensor is integral to the passenger side front seat belt lower anchor which is secured to the lower B-pillar, on the passenger side. The belt tension sensor consists of a molded plastic housing, a metal seat belt anchor loop, and a short pigtail wire. The electronic circuitry of the belt tension sensor is concealed and protected within the molded plastic housing.

The belt tension sensor cannot be repaired and, if faulty or damaged, the entire passenger side front seat belt and retractor unit must be replaced.

The belt tension sensor is designed to sense the relative cinch load applied to the passenger side front seat belt, which provides a logic input to the microprocessor of the Occupant Classification Module (OCM). When a load is applied to the seat belt, the changes in the load are measured by the belt tension sensor through the seat belt lower anchor. As the load changes, the circuitry of the belt tension sensor changes the output voltage of the sensor.

The belt tension sensor receives a nominal five volts and a ground from the OCM. The OCM then monitors the belt tension sensor output voltage.

WARNING: DO NOT CONNECT THE BATTERY BEFORE PERFORMING THE OCS VERIFICATION TEST USING THE SCAN TOOL AND THE APPROPRIATE DIAGNOSTIC INFORMATION. PERSONAL INJURY OR DEATH MAY OCCUR.

For further diagnosis and testing of the belt tension sensor, the OCM, and related occupant classification system components, use a scan tool and the appropriate diagnostic information