DTC    B1656/38    Seat Belt Buckle Switch LH Circuit Malfunction

for Preparation Click here


DESCRIPTION

The seat belt buckle switch LH circuit consists of the airbag sensor assembly and front seat inner belt assembly LH.
DTC B1656/38 is stored when a malfunction is detected in the seat belt buckle switch LH circuit.

DTC No.
DTC Detection Condition
Trouble Area
B1656/38
  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


C171040E30


INSPECTION PROCEDURE

NOTICE:
After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work (Click here).

1.CHECK CONNECTORS

  1. Turn the power switch off.

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

    CAUTION:
    Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary 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 SST, connect terminals 11 (LBE+) and 12 (LBE-) of connector B.


    C171045E19

    NOTICE:
    Do not forcibly insert SST into the terminals of the connector when connecting the wire.

SST
09843-18040  

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    P3-2 (LBE+) - P3-1 (LBE-)
    		Always
    		Below 1 Ω


    Text in Illustration 
    *1
    		Front Seat Inner Belt Assembly LH
    		*2
    		Airbag Sensor Assembly
    *3
    		Floor Wire
    		*4
    		Connector B
    *5
    		Connector C
    		-
    		-
    *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)



NG
REPLACE FLOOR WIRE
OK


3.CHECK FLOOR WIRE (SHORT)


    C234317E02

  1. Disconnect SST from connector B.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    P3-2 (LBE+) - P3-1 (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+)


    C234317E02

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

  1. Turn the power switch on (IG).

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    P3-2 (LBE+) - Body ground
    		Power switch on (IG)
    		Below 1 V
    P3-1 (LBE-) - Body ground
    		Power switch on (IG)
    		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)


    C234317E02

  1. Turn the power switch off.

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

    CAUTION:
    Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary 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
    P3-2 (LBE+) - Body ground
    		Always
    		1 MΩ or higher
    P3-1 (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


    C166120E08

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

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

  1. Turn the power switch on (IG), and wait for at least 60 seconds.

  1. Clear the DTCs stored in memory (Click here).

  1. Turn the power switch off.

  1. Turn the power switch on (IG), and wait for at least 60 seconds.

  1. Check for DTCs (Click here).

    OK:
    DTC B1656/38 is not output.

    Text in Illustration 
    *1
    		Front Seat Inner Belt Assembly LH
    *2
    		Airbag Sensor Assembly

    HINT:
    Codes other than DTC B1656/38 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 (Click here)  

7.REPLACE FRONT SEAT INNER BELT ASSEMBLY LH

  1. Turn the power switch off.

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

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

  1. Replace the front seat inner belt assembly LH with a known good one (Click here for Manual seat, Click here for Power seat).

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


NEXT


8.CHECK AIRBAG SENSOR ASSEMBLY


    C166120E08

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

  1. Turn the power switch on (IG), and wait for at least 60 seconds.

  1. Clear the DTCs stored in memory (Click here).

  1. Turn the power switch off.

  1. Turn the power switch on (IG), and wait for at least 60 seconds.

  1. Check for DTCs (Click here).

    OK:
    DTC B1656/38 is not output.

    Text in Illustration 
    *1
    		Front Seat Inner Belt Assembly LH
    *2
    		Airbag Sensor Assembly

    HINT:
    Codes other than DTC B1656/38 may be output at this time, but they are not related to this check.



NG
REPLACE AIRBAG SENSOR ASSEMBLY (Click here)
OK

END