Normal Operation and Fault Conditions

The Belt Tension Sensor (BTS) operates in conjunction with the OCS. The OCS interprets a variable voltage signal provided by the Belt Tension Sensor (BTS) to identify the possible presence of a child safety seat in the front passenger seat. The voltage output of the Belt Tension Sensor (BTS) is proportional to the amount of tension applied to the sensor by the belt: no belt tension causes a low voltage (approximately 0.95 volt) to be output and high belt tension causes a high voltage (approximately 3.8 volts) to be returned to the OCSM.

The OCSM monitors the Belt Tension Sensor (BTS) and related circuits for the following faults:

Resistance out of range
Unexpected voltage
Short to ground
Faulted Belt Tension Sensor (BTS) (part of right front passenger seatbelt buckle)

If a fault is detected, the OCSM stores DTC B0061:11, B0061:12, B0061:13, B0061:1C or B0061:49 in memory and sends a message to the RCM over the HS-CAN indicating that an OCS fault is present. Upon receipt of this message, the RCM sets DTC B00A0:09 and sends a message to the IPC to illuminate the airbag warning indicator.

PPT AX OCSM DTC FAULT TRIGGER CONDITIONS

DTC	Description	Fault Trigger Conditions
B0061:11	Passenger Seatbelt Tension Sensor: Circuit Short to Ground	Sets when the OCSM measures voltage below a predetermined threshold from the Belt Tension Sensor (BTS) signal circuit. An open Belt Tension Sensor (BTS) VREF circuit can also set this DTC.
B0061:12	Passenger Seatbelt Tension Sensor: Circuit Short to Battery	Sets when the OCSM measures voltage above a predetermined threshold from the Belt Tension Sensor (BTS) signal circuit. An open Belt Tension Sensor (BTS) return circuit can also set this DTC.
B0061:13	Passenger Seatbelt Tension Sensor: Circuit Open	Sets when the OCSM senses an open from the Belt Tension Sensor (BTS) circuit.
B0061:64	Passenger Seatbelt Tension Sensor: Signal Plausibility Failure	Sets when the passenger seatbelt is unbuckled and the OCSM measures voltage from the Belt Tension Sensor (BTS) signal circuit greater than the maximum voltage returned during normal sensor operation.