Dtc B1656/38 Seat Belt Buckle Switch Lh Circuit Malfunction

Vehicle Interior. Corolla. Zre142 Aze141
Supplemental Restraint Systems. Corolla. Zre142 Aze141

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 CENTER AIRBAG SENSOR ASSEMBLY

DTC B1656/38 Seat Belt Buckle Switch LH Circuit Malfunction


DESCRIPTION

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

DTC No.
DTC Detection Condition
Trouble Area
B1656/38
  1. The center airbag sensor assembly receives a short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the driver side seat belt buckle switch circuit for 2 seconds.
  2. Front seat inner belt assembly LH malfunction
  3. Center airbag sensor assembly malfunction
  1. Floor wire
  2. Front seat inner belt assembly LH (Driver side seat belt buckle switch)
  3. Center airbag sensor assembly

WIRING DIAGRAM


Corolla. Zre142 Aze141.Supplemental Restraint Systems.Airbag System. Dtc B1656/38 Seat Belt Buckle Switch Lh Circuit Malfunction


INSPECTION PROCEDURE

1.CHECK CONNECTORS

  1. Turn the ignition switch off.

  1. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

  1. Check that the connectors are properly connected to the center 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 center airbag sensor assembly and the 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.


    Corolla. Zre142 Aze141.Supplemental Restraint Systems.Airbag System. Dtc B1656/38 Seat Belt Buckle Switch Lh Circuit Malfunction

    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:
    for Power Seat:
    Tester Connection
    		Condition
    		Specified Condition
    L56-2 (LBE+) - L56-4 (LBE-)
    		Always
    		Below 1 Ω
    for Manual Seat:
    Tester Connection
    		Condition
    		Specified Condition
    L48-2 (LBE+) - L48-4 (LBE-)
    		Always
    		Below 1 Ω


NG
REPLACE FLOOR WIRE
OK


3.CHECK FLOOR WIRE (SHORT)


    Corolla. Zre142 Aze141.Supplemental Restraint Systems.Airbag System. Dtc B1656/38 Seat Belt Buckle Switch Lh Circuit Malfunction

  1. Disconnect SST from connector B.

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

    Standard Resistance:
    for Power Seat:
    Tester Connection
    		Condition
    		Specified Condition
    L56-2 (LBE+) - L56-4 (LBE-)
    		Always
    		1 MΩ or higher
    for Manual Seat:
    Tester Connection
    		Condition
    		Specified Condition
    L48-2 (LBE+) - L48-4 (LBE-)
    		Always
    		1 MΩ or higher


NG
REPLACE FLOOR WIRE
OK


4.CHECK FLOOR WIRE (SHORT TO B+)


    Corolla. Zre142 Aze141.Supplemental Restraint Systems.Airbag System. Dtc B1656/38 Seat Belt Buckle Switch Lh 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:
    for Power Seat:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L56-2 (LBE+) - Body ground
    		Ignition switch ON
    		Below 1 V
    L56-4 (LBE-) - Body ground
    		Ignition switch ON
    		Below 1 V
    for Manual Seat:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L48-2 (LBE+) - Body ground
    		Ignition switch ON
    		Below 1 V
    L48-4 (LBE-) - Body ground
    		Ignition switch ON
    		Below 1 V


NG
REPLACE FLOOR WIRE
OK


5.CHECK FLOOR WIRE (SHORT TO GROUND)


    Corolla. Zre142 Aze141.Supplemental Restraint Systems.Airbag System. Dtc B1656/38 Seat Belt Buckle Switch Lh Circuit Malfunction

  1. Turn the ignition switch off.

  1. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

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

    Standard Resistance:
    for Power Seat:
    Tester Connection
    		Condition
    		Specified Condition
    L56-2 (LBE+) - Body ground
    		Always
    		1 MΩ or higher
    L56-4 (LBE-) - Body ground
    		Always
    		1 MΩ or higher
    for Manual Seat:
    Tester Connection
    		Condition
    		Specified Condition
    L48-2 (LBE+) - Body ground
    		Always
    		1 MΩ or higher
    L48-4 (LBE-) - Body ground
    		Always
    		1 MΩ or higher


NG
REPLACE FLOOR WIRE
OK


6.CHECK FRONT SEAT INNER BELT ASSEMBLY LH


    Corolla. Zre142 Aze141.Supplemental Restraint Systems.Airbag System. Dtc B1656/38 Seat Belt Buckle Switch Lh Circuit Malfunction

  1. Connect the connectors to the center airbag sensor assembly and the 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 the memory (COROLLA_ZRE142 RM000000XFE0H1X.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 (COROLLA_ZRE142 RM000000XFE0H1X.html).

    OK:
    DTC B1656/38 is not output.
    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 (COROLLA_ZRE142 RM000000XFD0GSX.html)

7.REPLACE FRONT SEAT INNER BELT ASSEMBLY LH

  1. Turn the ignition switch off.

  1. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

  1. Replace the front seat inner belt assembly LH with a known good part (COROLLA_ZRE142 RM00000122H071X.html).

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

NEXT


8.CHECK CENTER AIRBAG SENSOR ASSEMBLY


    Corolla. Zre142 Aze141.Supplemental Restraint Systems.Airbag System. Dtc B1656/38 Seat Belt Buckle Switch Lh Circuit Malfunction

  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 the memory (COROLLA_ZRE142 RM000000XFE0H1X.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 (COROLLA_ZRE142 RM000000XFE0H1X.html).

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


NG
REPLACE CENTER AIRBAG SENSOR ASSEMBLY (COROLLA_ZRE142 RM000000UWV074X.html)
OK

END