LIN COMMUNICATION SYSTEM, Diagnostic DTC:B2789

DTC Code DTC Name
B2789 No Response from ID BOX

DESCRIPTION

This DTC is stored when LIN communication between the certification ECU (smart key ECU assembly) and ID code box (immobiliser code ECU) stops for 10 seconds or more.

DTC Code DTC Detection Condition Trouble Area
B2789 No communication between the certification ECU (smart key ECU assembly) and ID code box (immobiliser code ECU) for 10 seconds or more.

  • ID code box (immobiliser code ECU)

  • Certification ECU (smart key ECU assembly)

  • Harness or connector

WIRING DIAGRAM

A01EN67E20

INSPECTION PROCEDURE

Note

When using the intelligent tester with the engine 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 intelligent tester and vehicle begins.

Tech Tips

DTC B2785 is stored when the communication between the ID code box (immobiliser code ECU) and certification ECU (smart key ECU assembly) stops.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTC Click here.


    NEXT

  2. CHECK FOR DTC


    1. Recheck for DTCs Click here.

      Result
      Result Proceed to
      DTC B2789 is output A
      DTC B2789 is not output B

    B

    USE SIMULATION METHOD TO CHECK Click here

    A

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

    A01EPCKE01

    1. Disconnect the E29 ECU connector.

    2. Disconnect the E28 box connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E29-10 (LIN) - E28-3 (LIN1) Always Below 1 Ω
      E29-10 (LIN) or E28-3 (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. A01EQ36E03

      Disconnect the E28 box connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E28-8 (GND) - Body ground Always Below 1 Ω
      Standard Voltage
      Tester Connection Condition Specified Condition
      E28-1 (+B) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE ID CODE BOX (IMMOBILISER CODE ECU)


    1. Temporarily replace the ID code box (immobiliser code ECU) with a new or normally functioning one.

    2. Clear the DTC Click here.


    NEXT

  6. CHECK FOR DTC


    1. Recheck for DTCs Click here.

      Result
      Result Proceed to
      DTC B2789 is output A
      DTC B2789 is not output B

    B

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    A

    END (ID CODE BOX IS DEFECTIVE)