LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2010 >> RX 350 FWD >> Repair and Diagnosis >> Restraints >> Air Bag, SRS >> Supplemental Restraint System (Diagnostic Codes (B1627/82 - B1818/54) >> Airbag System >> DTC B1656/38: Seat Belt Buckle Switch LH Circuit Malfunction (2010 To 08/2009) >> Procedure

DTC B1656/38: Seat Belt Buckle Switch LH Circuit Malfunction (2010 To 08/2009): Procedure

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

      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 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  2the next inspection.

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

      OK

      The terminals are not deformed or damaged.

    NG → REPLACE NO. 2 FLOOR WIRE 

    OK: Go to next step 

  2. CHECK NO. 2 FLOOR WIRE (OPEN) 
    1. Using SST, connect terminals 10 (LBE+) and 18 (LBE-) of connector B.
      Fig 1: Checking No. 2 Floor Wire (Open) Using SST
      GTY285246Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      NOTE:

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

      • SST: 09843-18040 
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      P7-1 (LBE+) - P7-3 (LBE-) Always Below 1 Ω
      TEXT IN ILLUSTRATION

      *1 Front Seat Inner Belt Assembly LH (Seat Belt Buckle Switch LH) *2 Center Airbag Sensor Assembly
      *3 No. 2 Floor Wire *4 Front view of wire harness connector
      (to Center Airbag Sensor Assembly)
      *5 Front view of wire harness connector
      (to Front Seat Inner Belt Assembly LH)      		 *6 Connector B
      *7 Connector C - -

    NG → REPLACE NO. 2 FLOOR WIRE 

    OK: Go to next step 

  3. CHECK NO. 2 FLOOR WIRE (SHORT) 
    1. Disconnect SST from connector B.
      Fig 2: Checking No. 2 Floor Wire (Short)
      GTY283424Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      P7-1 (LBE+) - P7-3 (LBE-) Always 1 MΩ or higher
      TEXT IN ILLUSTRATION

      *1 Front Seat Inner Belt Assembly LH (Seat Belt Buckle Switch LH)
      *2 Center Airbag Sensor Assembly
      *3 No. 2 Floor Wire
      *4 Front view of wire harness connector
      (to Front Seat Inner Belt Assembly LH)
      *5 Connector C

    NG → REPLACE NO. 2 FLOOR WIRE 

    OK: Go to next step 

  4. CHECK NO. 2 FLOOR WIRE (SHORT TO B+) 
    1. Connect the cable to the negative (-) battery terminal.
      Fig 3: Checking No. 2 Floor Wire (Short)
      GTY283424Courtesy 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 Switch Condition Specified Condition
      P7-1 (LBE+) - Body ground Engine switch on (IG) Below 1 V
      P7-3 (LBE-) - Body ground Engine switch on (IG) Below 1 V
      TEXT IN ILLUSTRATION

      *1 Front Seat Inner Belt Assembly LH (Seat Belt Buckle Switch LH)
      *2 Center Airbag Sensor Assembly
      *3 No. 2 Floor Wire
      *4 Front view of wire harness connector
      (to Front Seat Inner Belt Assembly LH)
      *5 Connector C

    NG → REPLACE NO. 2 FLOOR WIRE 

    OK: Go to next step 

  5. CHECK NO. 2 FLOOR WIRE (SHORT TO GROUND) 
    1. Turn the engine switch off.
      Fig 4: Checking No. 2 Floor Wire (Short)
      GTY283424Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the cable from the negative (-) battery terminal.
      NOTE:

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

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      P7-1 (LBE+) - Body ground Always 1 MΩ or higher
      P7-3 (LBE-) - Body ground Always 1 MΩ or higher
      TEXT IN ILLUSTRATION

      *1 Front Seat Inner Belt Assembly LH (Seat Belt Buckle Switch LH)
      *2 Center Airbag Sensor Assembly
      *3 No. 2 Floor Wire
      *4 Front view of wire harness connector
      (to Front Seat Inner Belt Assembly LH)
      *5 Connector C

    NG → REPLACE NO. 2 FLOOR WIRE 

    OK: Go to next step 

  6. CHECK FRONT SEAT INNER BELT ASSEMBLY LH 
    1. Connect the connectors to the center airbag sensor assembly and front seat inner belt assembly LH.
      Fig 5: Identifying Side Airbag Sensor RH (For Rear Side) & Center Airbag Sensor Assembly
      GTY276807Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Connect the cable to the negative (-) battery terminal.
    3. Turn the engine switch on (IG), and wait for at least 60 seconds.
    4. Clear the DTCs stored in the memory. Refer to DTC CHECK / CLEAR .
    5. Turn the engine switch off.
    6. Turn the engine switch on (IG), and wait for at least 60 seconds.
    7. Check for DTCs. Refer to DTC CHECK / CLEAR .

      OK

      DTC B1656/38 is not output.

      TEXT IN ILLUSTRATION

      *1 Front Seat Inner Belt Assembly LH (Seat Belt Buckle Switch LH)
      *2 Center 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 → See step   7 

    OK → See step   9 

  7. REPLACE FRONT SEAT INNER BELT ASSEMBLY LH 
    1. Turn the engine switch off.
    2. Disconnect the cable from the negative (-) battery terminal.
      NOTE:

      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 part. Refer to REMOVAL .

      HINT: 

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

    NEXT: Go to next step 

  8. CHECK CENTER AIRBAG SENSOR ASSEMBLY 
    1. Connect the cable to the negative (-) battery terminal.
      Fig 6: Identifying Side Airbag Sensor RH (For Rear Side) & Center Airbag Sensor Assembly
      GTY276807Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Turn the engine switch on (IG), and wait for at least 60 seconds.
    3. Clear the DTCs stored in the memory. Refer to DTC CHECK / CLEAR .
    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 .

      OK

      DTC B1656/38 is not output.

      TEXT IN ILLUSTRATION

      *1 Front Seat Inner Belt Assembly LH (Seat Belt Buckle Switch LH)
      *2 Center 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 → See step   10 

    OK → END 

  9. USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING 
  10. REPLACE CENTER AIRBAG SENSOR ASSEMBLY. Refer to  REMOVAL 
scientia non olet · About LEMON Manuals