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 (smart key ECU assembly) and ID code box (immobiliser code ECU) stops for more than 10 seconds.

DTC No. DTC Detection Condition Trouble Area
B2789 No communication between certification ECU (smart key ECU assembly) and 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

A01UYTME11

CAUTION / NOTICE / HINT

Note


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

  • If the certification ECU (smart key ECU assembly) or ID code box (immobiliser code ECU) is replaced, refer to Service Bulletin.

  • When using the GTS with the ignition 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 GTS and vehicle begins.

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 F86 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the F43 ID code box (immobiliser code ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F86-17 (LIN) - F43-2 (LIN1) Always Below 1 Ω
      F86-17 (LIN) or F43-2 (LIN1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)

    A01V089E01
    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
      F43-1 (+B) - Body ground Ignition switch off 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F43-5 (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)