LIN COMMUNICATION SYSTEM, Diagnostic DTC:B2789

DTC Code DTC Name
B2789 No Response from ID BOX

DESCRIPTION

This DTC is output when LIN communication between the certification ECU and ID code box stops for 10 seconds or more.

DTC Code DTC Detection Condition Trouble Area
B2789 No communication between certification ECU and ID code box for 10 seconds or more

  • ID code box

  • Certification ECU

  • Harness or connector

WIRING DIAGRAM

A01H26NE80

INSPECTION PROCEDURE

Note


  • When using the intelligent tester with the power switch off to troubleshoot:

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

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

Tech Tips

DTC B2785 is output when the communication between all of the following components and certification ECU stops.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTC Click here.


    NEXT

  2. CHECK FOR DTC


    1. Recheck for DTC Click here.

      Result:
      Result Proceed to
      DTC B2789 output reoccurs A
      DTC B2789 output does not reoccur B

    B

    USE SIMULATION METHOD TO CHECK Click here

    A

  3. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - ID CODE BOX)

    A01GYZTE01

    1. Disconnect the L15 ECU connector.

    2. Disconnect the L32 box connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      L15-10 (LIN) - L32-3 (LIN1) Always Below 1 Ω
      L15-10 (LIN) or L32-3 (LIN1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (ID CODE BOX - BATTERY AND BODY GROUND)


    1. A01GYHOE02

      Disconnect the L32 box connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      L32-8 (GND) - Body ground Always Below 1 Ω
      Standard voltage
      Tester Connection Condition Specified Condition
      L32-1 (+B) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK ID CODE BOX (OPERATION)


    1. Temporarily replace the ID code box with a new or normally functioning one.

    2. Clear the DTC Click here.


    NEXT

  6. CHECK FOR DTC


    1. Recheck for DTC Click here.

      Result:
      Result Proceed to
      DTC B2789 output does not reoccur A
      DTC B2789 output reoccurs B

    B

    REPLACE CERTIFICATION ECU

    A

    END (ID CODE BOX IS DEFECTIVE)