LIN COMMUNICATION SYSTEM, Diagnostic DTC:B2785

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

DESCRIPTION

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

DTC Code DTC Detection Condition Trouble Area
B2785 Certification ECU detects malfunction in LIN communication bus between components related to certification continuously 3 times

  • Certification ECU

  • Main body ECU

  • Immobiliser code ECU (ID code box)

  • Steering lock actuator assembly (Steering lock ECU)

  • Wire harness

WIRING DIAGRAM

A001A6VE01
*a Certification ECU
*b Main Body ECU
*c ID Code Box
*d Steering Lock Actuator Assembly (Steering Lock ECU)

CAUTION / NOTICE / HINT

Note

When using the intelligent tester with the engine switch off to troubleshoot:

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

Tech Tips

When DTC B2785 and B2287 are output simultaneously, perform the troubleshooting for DTC B2785 first.

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - MAIN BODY ECU)

    A001EI6E01
    *1 Rear view of wire harness connector: (to Certification ECU)
    *2 Rear view of wire harness connector: (to Main Body ECU)

    1. Disconnect the L15 and DA ECU connectors.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      L15-10 (LIN) - DA-52 (LIN1) Always Below 1 Ω
      L15-10 (LIN) - Body ground Always 10 kΩ or higher
      Standard voltage
      Tester Connection Switch Condition Specified Condition
      L15-10 (LIN) - Body ground Engine switch on (IG) Below 1 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK FOR DTC


    1. Clear the DTC Click here.

    2. Reconnect the L15 ECU connector.

    3. Recheck for DTCs.

      Result:
      Result Proceed to
      DTC B2785 is output A
      DTC B2785 is not output B

    B

    REPLACE MAIN BODY ECU Click here

    A

  3. CHECK FOR DTC


    1. Clear the DTC Click here.

    2. Disconnect the DA ECU connector.

    3. Disconnect the L33 ECU connector.

    4. Recheck for DTCs.

      Result:
      Result Proceed to
      DTC B2785 is output A
      DTC B2785 is not output B

    B

    REPLACE STEERING LOCK ECU Click here

    A

  4. CHECK FOR DTC


    1. Clear the DTC Click here.

    2. Reconnect the L33 ECU connector.

    3. Disconnect the L32 box connector.

    4. Recheck for DTCs.

      Result:
      Result Proceed to
      DTC B2785 is output A
      DTC B2785 is not output B

    A

    REPLACE CERTIFICATION ECU

    B

    REPLACE ID CODE BOX Click here

  5. REPLACE MAIN BODY ECU


    1. Temporarily replace the main body ECU with a new or normally functioning one.

    2. Clear the DTC Click here.


    NEXT

  6. CHECK FOR DTC


    1. Recheck for DTCs.

      Result:
      Result Proceed to
      DTC B2785 is not output A
      DTC B2785 is output B

    A

    END (MAIN BODY ECU IS DEFECTIVE)

    B

    REPLACE CERTIFICATION ECU

  7. REPLACE STEERING LOCK ECU


    1. Temporarily replace the steering lock ECU with a new or normally functioning one Click here.

    2. Clear the DTC Click here.


    NEXT

  8. CHECK FOR DTC


    1. Recheck for DTCs.

      Result:
      Result Proceed to
      DTC B2785 is not output A
      DTC B2785 is output B

    A

    END (STEERING LOCK ECU IS DEFECTIVE)

    B

    REPLACE CERTIFICATION ECU

  9. REPLACE ID CODE BOX


    1. Temporarily replace the ID code box with a new or normally functioning one.

    2. Clear the DTC Click here.


    NEXT

  10. CHECK FOR DTC


    1. Recheck for DTCs Click here.

      Result:
      Result Proceed to
      DTC B2785 is not output A
      DTC B2785 is output B

    A

    END (ID CODE BOX IS DEFECTIVE)

    B

    REPLACE CERTIFICATION ECU