WIPER AND WASHER SYSTEM, Diagnostic DTC:B1279

DTC Code DTC Name
B1279 Lost Communication with Humidity/Rain Sensor LIN

DESCRIPTION

The main body ECU (multiplex network body ECU) and rain sensor communicate via LIN communication. The main body ECU (multiplex network body ECU) stores this DTC if communication becomes abnormal.

DTC No. Detection Item DTC Detection Condition Trouble Area Memory DTC Output from
B1279 Lost Communication with Humidity/Rain Sensor LIN

    Detection Condition:

  • Battery voltage is 9.5 V or more


    Malfunction Status:

  • Communication malfunction with rain sensor


    Malfunction Duration:

  • 10 seconds or more

  • Rain sensor

  • Harness or connector

  • Main body ECU (multiplex network body ECU)

 ○ Main body ECU (multiplex network body ECU)

WIRING DIAGRAM

B007009E01

CAUTION / NOTICE / HINT

Note


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

  • The vehicle battery supplies power to the main body ECU (multiplex network body ECU) via the door control battery. Therefore, before performing this troubleshooting procedure, make sure to perform an on-vehicle inspection to confirm that the main body ECU (multiplex network body ECU) power source circuit is normal.*1

    Click here

  • Before replacing the main body ECU (multiplex network body ECU), refer to Service Bulletin.*2


    • *1: w/ Door Control Battery

    • *2: w/ Smart Entry and Start System

PROCEDURE


  1. CHECK FOR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Main Body / Trouble Codes.

    5. Check for DTCs.


      Body Electrical > Main Body > Trouble Codes
      Result
      Result Proceed to
      Only DTC B1279 is output A
      DTC B1279 and B1373 are output B

    B

    GO TO DTC B1373 Click here

    A

  2. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) - RAIN SENSOR)


    1. Disconnect the K51 main body ECU (multiplex network body ECU) connector.

    2. Disconnect the V4*1 or V5*2 rain sensor 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
      K51-3 (LIN3) - V4-3 (MPX) Always Below 1 Ω
      for RHD
      Tester Connection Condition Specified Condition
      K51-3 (LIN3) - V5-3 (MPX) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

    B0070MNC01
    *a

    Component without harness connected

    (Main Body ECU (Multiplex Network Body ECU)

    1. Check for voltage and pulses according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      K51-3 (LIN3) - Body ground Ignition switch off Below 1 V
      Ignition switch ON Pulse generation
      Result
      Proceed to
      OK
      NG

    NG

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

    OK

  4. CHECK HARNESS AND CONNECTOR (POWER SOURCE - RAIN SENSOR)

    B006YBCC50
    *A for LHD
    *B for RHD
    *a

    Front view of wire harness connector

    (to Rain Sensor)

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

      Standard Voltage
      for LHD
      Tester Connection Condition Specified Condition
      V4-4 (SIG) - Body ground Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V
      for RHD
      Tester Connection Condition Specified Condition
      V5-4 (SIG) - Body ground Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (RAIN SENSOR - BODY GROUND)

    B006YBCC49
    *A for LHD
    *B for RHD
    *a

    Front view of wire harness connector

    (to Rain Sensor)

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      V4-2 (ES) - Body ground Always Below 1 Ω
      for RHD
      Tester Connection Condition Specified Condition
      V5-2 (ES) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE RAIN SENSOR Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR