DTC B1773: Belt Tension Sensor Circuit Malfunction; DTC B1776: Seat Belt Tension Sensor Power Source Circuit Malfunction: Description

WARNING: This page is about a different car, the 2009 Lexus GS 460 and 2009 Lexus GS 350. However, it is still accessible from the selected car via links, so may be relevant.

The seat belt tension sensor circuit consists of the occupant classification ECU and the seat belt tension sensor.

The seat belt tension sensor sends the seat belt tension signal to the occupant classification ECU.

DTC B1773 and B1776 are recorded when a malfunction is detected in the seat belt tension sensor circuit.

DTC No.	DTC Detection Condition	Trouble Area
B1773 B1776	One of following conditions is met: Occupant classification ECU receives line short circuit signal, and open circuit signal, short circuit to ground signal or short circuit to B+ signal in seat belt tension sensor circuit for 2 seconds Seat belt tension sensor malfunction Occupant classification ECU malfunction	Front seat wire RH Front seat outer belt RH (seat belt tension sensor) Occupant classification ECU

HINT:

When DTC B1650/32 is detected as a result of troubleshooting for the "AIRBAG SYSTEM", check the DTCs stored in the occupant classification ECU. When DTC B1773 and B1776 are output, perform troubleshooting for the DTC.