WIPER AND WASHER SYSTEM, Diagnostic DTC:B1278

DTC Code DTC Name
B1278 Lost Communication with Combination Switch ECU

DESCRIPTION

The main body ECU (multiplex network body ECU) and windshield wiper switch assembly communicate via LIN communication. The main body ECU (multiplex network body ECU) stores this DTC if the communication becomes abnormal.

DTC No. Detection Item DTC Detection Condition Trouble Area Memory DTC Output from
B1278 Lost Communication with Combination Switch ECU When the battery voltage is 9.5 V or more, a communication malfunction between the main body ECU (multiplex network body ECU) and windshield wiper switch assembly is detected for 10 seconds or more.

  • Windshield wiper switch assembly

  • Harness or connector

  • Main body ECU (multiplex network body ECU)

 ○ Main body ECU (multiplex network body ECU)

WIRING DIAGRAM


  1. for Wiper Switch RH Side Type:

    B007WW2E06

  2. for Wiper Switch LH Side Type:

    B007WW2E07

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > Main Body > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  2. CHECK FOR DTC


    1. Turn the engine switch on (IG).

    2. Check for DTCs.

      Click here


      Body Electrical > Main Body > Trouble Codes
      Result
      Result Proceed to
      DTC B1278 is not output. A
      DTC B1278 is output. B

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

  3. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) - WINDSHIELD WIPER SWITCH ASSEMBLY)


    1. Disconnect the J9 main body ECU (multiplex network body ECU) connector.

    2. Disconnect the J31 windshield wiper switch assembly connector.

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

      Standard Resistance
      for Wiper Switch RH Side Type
      Tester Connection Condition Specified Condition
      J9-8 (LIN3) - J31-7 (MPX1) Always Below 1 Ω
      J9-8 (LIN3) or J31-7 (MPX1) - Body ground Always 10 kΩ or higher
      for Wiper Switch LH Side Type
      Tester Connection Condition Specified Condition
      J9-8 (LIN3) - J31-8 (MPX1) Always Below 1 Ω
      J9-8 (LIN3) or J31-8 (MPX1) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (FRONT WIPER MOTOR AND LINK ASSEMBLY - POWER SOURCE)


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

      Standard Voltage
      for Wiper Switch RH Side Type
      Tester Connection Condition Specified Condition
      J31-10 (+B2) - Body ground Engine switch off Below 1 V
      Engine switch on (IG) 11 to 14 V
      J31-6 (+B) - Body ground Engine switch off Below 1 V
      Engine switch on (IG) 11 to 14 V
      for Wiper Switch LH Side Type
      Tester Connection Condition Specified Condition
      J31-5 (+B2) - Body ground Engine switch off Below 1 V
      Engine switch on (IG) 11 to 14 V
      J31-9 (+B) - Body ground Engine switch off Below 1 V
      Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (WINDSHIELD WIPER SWITCH ASSEMBLY - BODY GROUND)


    1. Disconnect the J33 windshield wiper switch assembly connector.

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

      Standard Resistance
      for Wiper Switch RH Side Type
      Tester Connection Condition Specified Condition
      J31-8 (E) - Body ground Always Below 1 Ω
      J33-4 (EW) - Body ground Always Below 1 Ω
      for Wiper Switch LH Side Type
      Tester Connection Condition Specified Condition
      J31-7 (E) - Body ground Always Below 1 Ω
      J33-7 (EW) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. REPLACE WINDSHIELD WIPER SWITCH ASSEMBLY


    1. Replace the windshield wiper switch assembly with a new or known good one.

      Click here

    2. Turn the engine switch on (IG).

    3. Check for DTCs.

      Click here


      Body Electrical > Main Body > Trouble Codes
      Result
      Result Proceed to
      DTC B1278 is not output. A
      DTC B1278 is output. B

    A

    END

    B

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