DTC B1656/38: Seat Belt Buckle Switch LH Circuit Malfunction: Procedure

1. Turn the engine switch off.
2. Disconnect the cable from the negative (-) battery terminal.
   WARNING:

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

3. 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.

4. Disconnect the connectors from the airbag sensor assembly and front seat inner belt assembly LH.
5. Check that the terminals of the connectors are not damaged.

   OK

   The terminals are not deformed or damaged.

NG → REPLACE FLOOR WIRE 

OK: Go to next step 

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NOTE:

   Do not forcibly insert the service wire into the terminals of the connector when connecting the wire.

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   P20-2 (LBE+) - P20-1 (LBE-)	Always	Below 1 Ω

3. Disconnect the service wire from connector B.
   TEXT IN ILLUSTRATION
   
   

   *1	Front Seat Inner Belt Assembly LH
   *2	Airbag Sensor Assembly
   *3	Floor Wire
   *4	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)

NG → REPLACE FLOOR WIRE 

OK: Go to next step 

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   P20-2 (LBE+) - P20-1 (LBE-)	Always	1 MΩ or higher

   TEXT IN ILLUSTRATION
   
   

   *1	Front Seat Inner Belt Assembly LH
   *2	Airbag Sensor Assembly
   *3	Floor Wire
   *a	Front view of wire harness connector (to Front Seat Inner Belt Assembly LH)

NG → REPLACE FLOOR WIRE 

OK: Go to next step 

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Turn the engine switch on (IG).
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   P20-2 (LBE+) - Body ground	Engine switch on (IG)	Below 1 V
   P20-1 (LBE-) - Body ground	Engine switch on (IG)	Below 1 V

4. Turn the engine switch off.
5. Disconnect the cable from the negative (-) battery terminal.
   WARNING:

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

   TEXT IN ILLUSTRATION
   
   

   *1	Front Seat Inner Belt Assembly LH
   *2	Airbag Sensor Assembly
   *3	Floor Wire
   *a	Front view of wire harness connector (to Front Seat Inner Belt Assembly LH)

NG → REPLACE FLOOR WIRE 

OK: Go to next step 

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   P20-2 (LBE+) - Body ground	Always	1 MΩ or higher
   P20-1 (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
   *a	Front view of wire harness connector (to Front Seat Inner Belt Assembly LH)

NG → REPLACE FLOOR WIRE 

OK: Go to next step 

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Connect the cable to the negative (-) battery terminal.
3. Clear the DTCs stored in memory. Refer to DTC CHECK / CLEAR [06/2012 - ] .
4. Turn the engine switch off.
5. Turn the engine switch on (IG), and wait for at least 60 seconds.
6. Check for DTCs. Refer to DTC CHECK / CLEAR [06/2012 - ] .

   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.

   TEXT IN ILLUSTRATION
   
   

   *1	Front Seat Inner Belt Assembly LH
   *2	Airbag Sensor Assembly

NG → See step   7 

OK → See step   8 

1. Turn the engine switch off.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Disconnect the cable from the negative (-) battery terminal.
   WARNING:

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

3. Replace the front seat inner belt assembly LH with a known good one. Refer to REMOVAL [06/2012 - ] .

   HINT: 

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

4. Connect the cable to the negative (-) battery terminal.
5. Clear the DTCs stored in memory. Refer to DTC CHECK / CLEAR [06/2012 - ] .
6. Turn the engine switch off.
7. Turn the engine switch on (IG), and wait for at least 60 seconds.
8. Check for DTCs. Refer to DTC CHECK / CLEAR [06/2012 - ] .

   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.

9. Turn the engine switch off.
10. Disconnect the cable from the negative (-) battery terminal.
    WARNING:

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

11. Restore the front seat inner belt assembly LH that was installed for testing to its original location. Refer to REMOVAL [06/2012 - ] .
    TEXT IN ILLUSTRATION
    
    

    *1	Front Seat Inner Belt Assembly LH
    *2	Airbag Sensor Assembly

NG → See step   9 

OK → See step   10