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 No. DTC Detection Condition Trouble Area
B2789 No communication between 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)

  • Wire harness or connector

  • SMART fuse

WIRING DIAGRAM

B000I0PE04

INSPECTION PROCEDURE

Note


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

  • If the certification ECU (smart key ECU assembly) is replaced, register the keys (refer to the Service Bulletin).

  • If the ID code box (immobiliser code ECU) is replaced, register the ECU code and ECU communication ID (refer to the Service Bulletin).

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

    Connect the intelligent tester to the DLC3, and turn the courtesy switch on and off at 1.5-second intervals until communication between the intelligent tester and vehicle begins.

PROCEDURE


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


    1. Disconnect the I20 ID code box (immobiliser code ECU).

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I20-5 (GND) - Body ground Always Below 1 Ω
      Standard Voltage
      Tester Connection Condition Specified Condition
      I20-1 (+B) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the I78 certification ECU (smart key ECU assembly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I78-17 (LIN) - I20-2 (LIN1) Always Below 1 Ω
      I78-17 (LIN) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. REPLACE ID CODE BOX (IMMOBILISER CODE ECU)


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

      Tech Tips

      Refer to the Service Bulletin.


    NEXT

  4. CHECK DTC OUTPUT


    1. Clear the DTC Click here.

    2. Recheck for DTCs.

      OK
      DTC B2789 is not output.

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    OK

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