LIN COMMUNICATION SYSTEM, Diagnostic DTC:B2789

DTC Code DTC Name
B2789 No Response from ID BOX

DESCRIPTION

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

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

  • ID code box (immobiliser code ECU)

  • Certification ECU (smart key ECU assembly)

  • Harness or connector

WIRING DIAGRAM

A004HEVE12

CAUTION / NOTICE / HINT

Note


  • When replacing the ID code box (immobiliser code ECU) or certification ECU (smart key ECU assembly), refer to the registration procedures for the Service Bulletin.

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

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

  • Inspect the fuses for this circuit before starting this inspection procedure.

Tech Tips

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

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTC Click here.


    NEXT

  2. CHECK DTC


    1. Check for DTC Click here.

      Result
      Result Proceed to
      DTC B2789 is output A
      DTC B2789 and B2785 is output B

      Tech Tips

      When both B2789 and B2785 are output at the same time, troubleshoot B2785 first.


    B

    GO TO DIAGNOSTIC TROUBLE CODE CHART Click here

    A

  3. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ID CODE BOX (IMMOBILISER CODE ECU))


    1. Disconnect the D41 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the A30 ID code box (immobiliser code ECU) connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      D41-17 (LIN) - A30-2 (LIN) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      D41-17 (LIN) or A30-2 (LIN) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)

    A004HVIE01
    Text in Illustration
    *a

    Front view of wire harness connector

    (to ID Code Box (Immobiliser Code ECU))

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A30-1 (+B) - Body ground Always 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A30-5 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

  5. REPLACE ID CODE BOX (IMMOBILISER CODE ECU)


    1. Replace the ID code box (immobiliser code ECU).


    NEXT

  6. CHECK FOR DTC


    1. Clear the DTC Click here.

    2. Recheck for DTC.

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

    A

    END (ID CODE BOX (IMMOBILISER CODE ECU) WAS DEFECTIVE)

    B

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)