Test Q: DTC B2909 - Belt Tension Sensor Fault

PINPOINT TEST Q: DTC B2909 - BELT TENSION SENSOR FAULT

Normal Operation
The belt tension sensor operates in conjunction with the occupant classification sensor (OCS) system. The OCS system interprets a variable voltage signal provided by the safety belt tension sensor to identify the possible presence of a child safety seat in the front passenger seat. The voltage output of the belt tension sensor is proportional to the amount of tension applied to the sensor by the belt, no tension low voltage (approximately 0.95 volt), high tension high voltage (approximately 3.8 volts).

The occupant classification system module (OCSM) monitors the pressure sensor and circuitry for faults. If the OCSM detects a fault on any of the belt tension sensor circuits, it will store DTC B2909 in memory and send a message to the restraints control module (RCM), which will store DTC B2290 in memory and send a message to the instrument cluster (IC) module to illuminate the air bag warning indicator.

The OCS system components (seat wiring harness, seat cushion frame, seat cushion foam pad, bladder with pressure sensor and occupant classification system module [OCSM]) are calibrated to each other and are serviced as an assembly. The OCS system components are not to be installed separately with the exception of the belt tension sensor. If a new OCS system, OCS system component or seat cushion foam pad are needed, a new OCS system service kit (seat cushion foam pad, bladder with pressure sensor, seat wiring harness and OCSM) must be installed as an assembly.