LIN COMMUNICATION SYSTEM, Diagnostic DTC:B2785

DTC Code DTC Name
B2785 Communication Malfunction between ECUs Connected by LIN

DESCRIPTION

The certification ECU intermittently monitors the LIN communication bus between the components related to certification. DTC B2785 is stored when a malfunction in the LIN communication bus between the components related to certification is detected 3 times consecutively.

DTC No. Detection Item DTC Detection Condition Trouble Area
B2785 Communication Malfunction between ECUs Connected by LIN The certification ECU detects a malfunction in the LIN communication bus between components related to certification 3 times consecutively.

  • Certification ECU (smart key ECU assembly)

  • ID code box (immobiliser code ECU)

  • Steering lock actuator or upper bracket assembly

  • Harness or connector

WIRING DIAGRAM

B000WOYE02

CAUTION / NOTICE / HINT

Note


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

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

  • Before replacing the certification ECU (smart key ECU assembly), ID code box (immobiliser code ECU) or steering lock actuator or upper bracket assembly, refer to the engine immobiliser system.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > Entry&Start > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs.

      Click here


      Body Electrical > Entry&Start > Trouble Codes
      Result
      Proceed to
      DTC B2785 is output
      DTC B2785 is not output

    DTC B2785 is not output

    USE SIMULATION METHOD TO CHECK Click here

    DTC B2785 is output

  3. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU [SMART KEY ECU ASSEMBLY] - ID CODE BOX [IMMOBILISER CODE ECU] AND STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY)


    1. Disconnect the P66 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the P51 ID code box (immobiliser code ECU) connector.

    3. Disconnect the P14 steering lock actuator or upper bracket assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      P66-13 (LIN) - P14-5 (LIN) Always Below 1 Ω
      P66-13 (LIN) - P51-2 (LIN1) Always Below 1 Ω
      P66-13 (LIN) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU [SMART KEY ECU ASSEMBLY] - DRIVER SIDE JUNCTION BLOCK ASSEMBLY) Click here

    OK

  4. REPLACE STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY


    1. Temporarily replace the steering lock actuator or upper bracket assembly with a new one.

      Click here

    2. Clear the DTCs.

      Click here


      Body Electrical > Entry&Start > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK FOR DTC


    1. Check for DTCs.

      Click here


      Body Electrical > Entry&Start > Trouble Codes
      Result
      Proceed to
      DTC B2785 is output
      DTC B2785 is not output

    DTC B2785 is not output

    END (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY IS DEFECTIVE)

    DTC B2785 is output

  6. REPLACE ID CODE BOX (IMMOBILISER CODE ECU)


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

      Click here

    2. Clear the DTCs.

      Click here


      Body Electrical > Entry&Start > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  7. CHECK FOR DTC


    1. Check for DTCs.

      Click here


      Body Electrical > Entry&Start > Trouble Codes
      Result
      Proceed to
      DTC B2785 is output
      DTC B2785 is not output

    DTC B2785 is output

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    DTC B2785 is not output

    END (ID CODE BOX [IMMOBILISER CODE ECU] IS DEFECTIVE)

  8. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU [SMART KEY ECU ASSEMBLY] - DRIVER SIDE JUNCTION BLOCK ASSEMBLY)


    1. Disconnect the P66 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the 3B driver side junction block assembly connector.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      P66-13 (LIN) - 3B-27 Always Below 1 Ω
      P66-13 (LIN) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      P66-13 (LIN) - 3B-17 Always Below 1 Ω
      P66-13 (LIN) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. CHECK HARNESS AND CONNECTOR (ID CODE BOX [IMMOBILISER CODE ECU] - DRIVER SIDE JUNCTION BLOCK ASSEMBLY)


    1. Disconnect the P51 ID code box (immobiliser code ECU) connector.

    2. Disconnect the 3B driver side junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      P51-2 (LIN1) - 3B-16 Always Below 1 Ω
      P51-2 (LIN1) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. CHECK HARNESS AND CONNECTOR (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY - DRIVER SIDE JUNCTION BLOCK ASSEMBLY)


    1. Disconnect the P14 steering lock actuator or upper bracket assembly connector.

    2. Disconnect the 3B driver side junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      P14-5 (LIN) - 3B-15 Always Below 1 Ω
      P14-5 (LIN) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE DRIVER SIDE JUNCTION BLOCK ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR