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 10 seconds or more.

DTC Code 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
  • Certification ECU (smart key ECU assembly)

  • ID code box (immobiliser code ECU)

  • Harness or connector

WIRING DIAGRAM

A003BU5E05

INSPECTION PROCEDURE

Note


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

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

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

  • Before replacing the certification ECU (smart key ECU assembly), refer to the smart entry and start system (for Entry Function) Click here.

Tech Tips

DTC B2785 is output when the communication between all of the following components and certification ECU (smart key ECU assembly) stops.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTC Click here.


    NEXT
  2. CHECK FOR DTC


    1. Check for DTCs Click here.

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

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


    1. Disconnect the B75 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the H81 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
      B75-5 (LIN) - H81-2 (LIN1) Always Below 1 Ω
      B75-5 (LIN) - Body ground Always 10 kΩ or higher

    NG
    OK
  4. CHECK HARNESS AND CONNECTOR (ID CODE BOX [IMMOBILIZER CODE ECU] - BATTERY AND BODY GROUND)

    A003HD6E02
    Text in Illustration
    *a

    Front view of wire harness connector

    (to ID Code Box [Immobilizer Code ECU])


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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H81-5 (GND) - Body ground Always Below 1 Ω
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      H81-1 (+B) - Body ground Always 11 to 14 V

    NG
    OK
  5. REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)


    1. Temporarily replace the certification ECU (smart key ECU assembly) with a new one.


    NEXT
  6. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT
  7. CHECK FOR DTC


    1. Check for DTCs Click here.

      OK
      DTC B2789 is not output.

    NG
    OK