LIN COMMUNICATION SYSTEM, Diagnostic DTC:B1206

DTC Code DTC Name
B1206 P/W Master Switch Communication Stop

DESCRIPTION

This DTC is output when LIN communication between the master switch and main body ECU (multiplex network body ECU) stops for 10 seconds or more.

DTC Code DTC Detection Condition Trouble Area
B1206 No communication between master switch and main body ECU (multiplex network body ECU) for 10 seconds or more

  • Main body ECU (multiplex network body ECU)

  • Front multiplex network door ECU LH (for LHD)

  • Front multiplex network door ECU RH (for RHD)

  • Multiplex network master switch assembly

  • Harness or connector

WIRING DIAGRAM

A01FTX9E05
A01FTX9E06

INSPECTION PROCEDURE

Note


  • When using the GTS with the power switch off to troubleshoot:

    Connect the GTS to the vehicle, and turn a courtesy switch on and off at 1.5 seconds intervals until communication between the GTS and vehicle begins.

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

  • If the main body ECU (multiplex network body ECU) is replaced, refer to the Service Bulletin.

Tech Tips

DTC B2325 is output when the communication between all of the following components and main body ECU (multiplex network body ECU) stops.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC B1206 is output A
      DTC B1206 is not output B

    B

    USE SIMULATION METHOD TO CHECK Click here

    A

  3. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU] - MULTIPLEX NETWORK MASTER SWITCH ASSEMBLY)


    1. Remove the main body ECU (multiplex network body ECU) from the cowl side junction block LH Click here.

    2. Disconnect the Q25*1 or Q10*2 multiplex network master switch assembly connector.


      • *1: for LHD

      • *2: for RHD

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      A-16 (LIN2) - Q25-17 (LIN1) Always Below 1 Ω
      A-16 (LIN2) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      A-16 (LIN2) - Q10-17 (LIN1) Always Below 1 Ω
      A-16 (LIN2) - Body ground Always 10 kΩ or higher

    NG

    CHECK HARNESS AND CONNECTOR (MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU] - FRONT MULTIPLEX NETWORK DOOR ECU) Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (FRONT MULTIPLEX NETWORK DOOR ECU - BATTERY AND BODY GROUND)

    A01FUARE09
    Text in Illustration
    *A for LHD
    *B for RHD
    *a

    Front view of wire harness connector

    (to Front Multiplex Network Door ECU)

    1. Disconnect the front multiplex network door ECU LH*1 or front multiplex network door ECU RH*2 connector.


      • *1: for LHD

      • *2: for RHD

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      Q19-1 (GND) - Body ground Always Below 1 Ω
      for RHD
      Tester Connection Condition Specified Condition
      Q4-1 (GND) - Body ground Always Below 1 Ω

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

      Standard Voltage
      for LHD
      Tester Connection Condition Specified Condition
      Q19-6 (BDR) - Q19-1 (GND) Always 11 to 14 V
      Q19-16 (BCUT) - Q19-1 (GND) Always 11 to 14 V
      for RHD
      Tester Connection Condition Specified Condition
      Q4-6 (BDR) - Q4-1 (GND) Always 11 to 14 V
      Q4-16 (BCUT) - Q4-1 (GND) Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (FRONT MULTIPLEX NETWORK DOOR ECU - MULTIPLEX NETWORK MASTER SWITCH ASSEMBLY)


    • *1: for LHD

    • *2: for RHD


    1. Disconnect the Q19 front multiplex network door ECU LH*1 or Q4 front multiplex network door ECU RH*2 connector.

    2. Disconnect the Q25*1 or Q10*2 multiplex network master switch assembly connector.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      Q19-15 (CPBJ) - Q25-11 (B) Always Below 1 Ω
      Q19-9 (SGND) - Q25-12 (GND) Always Below 1 Ω
      Q19-15 (CPBJ) - Body ground Always 10 kΩ or higher
      Q19-9 (SGND) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      Q4-15 (CPBJ) - Q10-11 (B) Always Below 1 Ω
      Q4-9 (SGND) - Q10-12 (GND) Always Below 1 Ω
      Q4-15 (CPBJ) - Body ground Always 10 kΩ or higher
      Q4-9 (SGND) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK FRONT MULTIPLEX NETWORK DOOR ECU

    A01FQ1IE02
    Text in Illustration
    *A for LHD
    *B for RHD
    *a

    Front view of wire harness connector

    (to Multiplex Network Master Switch Assembly)

    1. Disconnect the multiplex network master switch assembly connector.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      Q25-12 (GND) - Body ground Always Below 1 Ω
      for RHD
      Tester Connection Condition Specified Condition
      Q10-12 (GND) - Body ground Always Below 1 Ω

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

      Standard Voltage
      for LHD
      Tester Connection Condition Specified Condition
      Q25-11 (B) - Body ground Always 11 to 14 V
      for RHD
      Tester Connection Condition Specified Condition
      Q10-11 (B) - Body ground Always 11 to 14 V
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    B

    REPLACE FRONT MULTIPLEX NETWORK DOOR ECU LH Click here

    C

    REPLACE FRONT MULTIPLEX NETWORK DOOR ECU RH Click here

    A

  7. REPLACE MULTIPLEX NETWORK MASTER SWITCH ASSEMBLY


    1. Temporarily replace the master switch with a new or normally functioning one Click here.


    NEXT

  8. CHECK FOR DTC


    1. Clear the DTC Click here.

    2. Check for DTCs Click here.

      OK
      DTC B1206 is not output.

    NG

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    OK

    END (MULTIPLEX NETWORK MASTER SWITCH ASSEMBLY IS DEFECTIVE)

  9. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU] - FRONT MULTIPLEX NETWORK DOOR ECU)


    1. Remove the main body ECU (multiplex network body ECU) from the cowl side junction block LH Click here.

    2. Disconnect the Q18 front multiplex network door ECU LH*1 or Q3 front multiplex network door ECU RH*2 connector.


      • *1: for LHD

      • *2: for RHD

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      A-16 (LIN2) - Q18-18 (LIN1) Always Below 1 Ω
      A-16 (LIN2) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      A-16 (LIN2) - Q3-18 (LIN1) Always Below 1 Ω
      A-16 (LIN2) - Body ground Always 10 kΩ or higher

    NG

    CHECK HARNESS AND CONNECTOR (COWL SIDE JUNCTION BLOCK LH - FRONT MULTIPLEX NETWORK DOOR ECU) Click here

    OK

  10. CHECK HARNESS AND CONNECTOR (FRONT MULTIPLEX NETWORK DOOR ECU - MULTIPLEX NETWORK MASTER SWITCH ASSEMBLY)


    • *1: for LHD

    • *2: for RHD


    1. Disconnect the Q18 front multiplex network door ECU LH*1 or Q3 front multiplex network door ECU RH*2 connector.

    2. Disconnect the Q25*1 or Q10*2 multiplex network master switch assembly connector.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      Q18-8 (LIN2) - Q25-17 (LIN1) Always Below 1 Ω
      Q18-8 (LIN2) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      Q3-8 (LIN2) - Q10-17 (LIN1) Always Below 1 Ω
      Q3-8 (LIN2) - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      NG A
      OK (for LHD) B
      OK (for RHD) C

    B

    REPLACE FRONT MULTIPLEX NETWORK DOOR ECU LH Click here

    C

    REPLACE FRONT MULTIPLEX NETWORK DOOR ECU RH Click here

    A

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  11. CHECK HARNESS AND CONNECTOR (COWL SIDE JUNCTION BLOCK LH - FRONT MULTIPLEX NETWORK DOOR ECU)


    • *1: for LHD

    • *2: for RHD


    1. Disconnect the 5C*1 or 5A*2 cowl side junction block LH connector.

    2. Disconnect the Q18 front multiplex network door ECU LH*1 or Q3 front multiplex network door ECU RH*2 connector.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      5C-28 - Q18-18 (LIN1) Always Below 1 Ω
      5C-28 - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      5A-56 - Q3-18 (LIN1) Always Below 1 Ω
      5A-56 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE COWL SIDE JUNCTION BLOCK LH Click here