Dtc B1655/37 Driver Side Seat Belt Buckle Switch Circuit Malfunction

Vehicle Interior. Yaris. Ncp93, 131
Supplemental Restraint Systems. Yaris. Ncp93, 131

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK CONNECTORS

CHECK FLOOR WIRE (OPEN)

CHECK FLOOR WIRE (SHORT)

CHECK FLOOR WIRE (SHORT TO B+)

CHECK FLOOR WIRE (SHORT TO GROUND)

CHECK FRONT SEAT INNER BELT ASSEMBLY LH

REPLACE FRONT SEAT INNER BELT ASSEMBLY LH

CHECK DTC

DTC B1655/37 Driver Side Seat Belt Buckle Switch Circuit Malfunction


DESCRIPTION

The seat belt buckle switch LH circuit consists of the airbag sensor assembly and front seat inner belt assembly LH.
DTC B1655/37 is stored when a malfunction is detected in the seat belt buckle switch LH circuit.

DTC No.
DTC Detection Condition
Trouble Area
B1655/37
  1. The airbag sensor assembly receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the seat belt buckle switch LH circuit.
  2. Front seat inner belt assembly LH malfunction
  3. Airbag sensor assembly malfunction
  1. Floor wire
  2. Front seat inner belt assembly LH (Seat belt buckle switch LH)
  3. Airbag sensor assembly

WIRING DIAGRAM


Yaris. Ncp93, 131.Supplemental Restraint Systems.Airbag System (For Sedan). Dtc B1655/37 Driver Side Seat Belt Buckle Switch Circuit Malfunction


INSPECTION PROCEDURE

1.CHECK CONNECTORS

  1. Turn the ignition switch off.

  1. Disconnect the cable from the negative (-) battery terminal.

    CAUTION:
    Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

  1. Check that the connectors are properly connected to the airbag sensor assembly and front seat inner belt assembly LH.

    OK:
    The connectors are properly connected.
    HINT:
    If the connectors are not connected securely, reconnect the connectors and proceed to the next inspection.

  1. Disconnect the connectors from the airbag sensor assembly and front seat inner belt assembly LH.

  1. Check that the terminals of the connectors are not damaged.

    OK:
    The terminals are not deformed or damaged.


NG
REPLACE FLOOR WIRE
OK


2.CHECK FLOOR WIRE (OPEN)


  1. Using the service wire, connect terminals 10 (LBE+) and 18 (LBE-) of connector B.


    Yaris. Ncp93, 131.Supplemental Restraint Systems.Airbag System (For Sedan). Dtc B1655/37 Driver Side Seat Belt Buckle Switch Circuit Malfunction


    Text in Illustration
    *1
    		Front Seat Inner Belt Assembly LH
    		*2
    		Airbag Sensor Assembly
    *3
    		Floor Wire
    		*4
    		Connector B
    *5
    		Connector C
    		*6
    		Service Wire
    *a
    		Front view of wire harness connector
    (to Airbag Sensor Assembly)
    		*b
    		Front view of wire harness connector
    (to Front Seat Inner Belt Assembly LH)
    NOTICE:
    Do not forcibly insert the service wire into the terminals of the connector when connecting the wire.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    J67-2 (LBE+) - J67-1 (LBE-)
    		Always
    		Below 1 Ω


NG
REPLACE FLOOR WIRE
OK


3.CHECK FLOOR WIRE (SHORT)


    Yaris. Ncp93, 131.Supplemental Restraint Systems.Airbag System (For Sedan). Dtc B1655/37 Driver Side Seat Belt Buckle Switch Circuit Malfunction

  1. Disconnect the service wire from connector B.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    J67-2 (LBE+) - J67-1 (LBE-)
    		Always
    		1 MΩ or higher
    Text in Illustration
    *1
    		Front Seat Inner Belt Assembly LH
    *2
    		Airbag Sensor Assembly
    *3
    		Floor Wire
    *4
    		Connector C
    *a
    		Front view of wire harness connector
    (to Front Seat Inner Belt Assembly LH)


NG
REPLACE FLOOR WIRE
OK


4.CHECK FLOOR WIRE (SHORT TO B+)


    Yaris. Ncp93, 131.Supplemental Restraint Systems.Airbag System (For Sedan). Dtc B1655/37 Driver Side Seat Belt Buckle Switch Circuit Malfunction

  1. Connect the cable to the negative (-) battery terminal.

  1. Turn the ignition switch to ON.

  1. Measure the voltage according to the value(s) in the table below.

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    J67-2 (LBE+) - Body ground
    		Ignition switch ON
    		Below 1 V
    J67-1 (LBE-) - Body ground
    		Ignition switch ON
    		Below 1 V
    Text in Illustration
    *1
    		Front Seat Inner Belt Assembly LH
    *2
    		Airbag Sensor Assembly
    *3
    		Floor Wire
    *4
    		Connector C
    *a
    		Front view of wire harness connector
    (to Front Seat Inner Belt Assembly LH)


NG
REPLACE FLOOR WIRE
OK


5.CHECK FLOOR WIRE (SHORT TO GROUND)


    Yaris. Ncp93, 131.Supplemental Restraint Systems.Airbag System (For Sedan). Dtc B1655/37 Driver Side Seat Belt Buckle Switch Circuit Malfunction

  1. Turn the ignition switch off.

  1. Disconnect the cable from the negative (-) battery terminal.

    CAUTION:
    Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    J67-2 (LBE+) - Body ground
    		Always
    		1 MΩ or higher
    J67-1 (LBE-) - Body ground
    		Always
    		1 MΩ or higher
    Text in Illustration
    *1
    		Front Seat Inner Belt Assembly LH
    *2
    		Airbag Sensor Assembly
    *3
    		Floor Wire
    *4
    		Connector C
    *a
    		Front view of wire harness connector
    (to Front Seat Inner Belt Assembly LH)


NG
REPLACE FLOOR WIRE
OK


6.CHECK FRONT SEAT INNER BELT ASSEMBLY LH

  1. Connect the connectors to the airbag sensor assembly and front seat inner belt assembly LH.

  1. Connect the cable to the negative (-) battery terminal.

  1. Turn the ignition switch to ON, and wait for at least 60 seconds.

  1. Clear the DTCs stored in memory (YARIS_NCP93 RM000000XFE0EEX.html).

  1. Turn the ignition switch off.

  1. Turn the ignition switch to ON, and wait for at least 60 seconds.

  1. Check for DTCs (YARIS_NCP93 RM000000XFE0EEX.html).

    OK:
    DTC B1655/37 is not output.
    HINT:
    Codes other than DTC B1655/37 may be output at this time, but they are not related to this check.


NG
Go to step 7
OK

USE SIMULATION METHOD TO CHECK (YARIS_NCP93 RM00000135202EX.html)

7.REPLACE FRONT SEAT INNER BELT ASSEMBLY LH

  1. Turn the ignition switch off.

  1. Disconnect the cable from the negative (-) battery terminal.

    CAUTION:
    Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

  1. Replace the front seat inner belt assembly LH with a known good one (YARIS_NCP93 RM000000SY000SX.html).

    HINT:
    Perform the following inspection using known good parts from another vehicle if possible.

NEXT


8.CHECK DTC

  1. Connect the cable to the negative (-) battery terminal.

  1. Turn the ignition switch to ON, and wait for at least 60 seconds.

  1. Clear the DTCs stored in memory (YARIS_NCP93 RM000000XFE0EEX.html).

  1. Turn the ignition switch off.

  1. Turn the ignition switch to ON, and wait for at least 60 seconds.

  1. Check for DTCs (YARIS_NCP93 RM000000XFE0EEX.html).

    OK:
    DTC B1655/37 is not output.
    HINT:
    Codes other than DTC B1655/37 may be output at this time, but they are not related to this check.


NG
REPLACE AIRBAG SENSOR ASSEMBLY (YARIS_NCP93 RM000000V6U02AX.html)
OK

END (FRONT SEAT INNER BELT ASSEMBLY LH WAS DEFECTIVE)