LIN COMMUNICATION SYSTEM, Diagnostic DTC:B2785

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

DESCRIPTION

The certification ECU (smart key ECU assembly) monitors communication between all the ECUs connected to the certification bus lines. When the certification ECU (smart key ECU assembly) detects errors in communication with all the ECUs connected to the certification bus lines at a set interval and 3 times in a row, DTC B2785 will be stored.

DTC No. DTC Detection Condition Trouble Area
B2785

  • Errors in LIN communication between ECUs or an open or short in communication lines

  • LIN communication from the certification ECU (smart key ECU assembly) detects errors in communication 3 times in a row.

  • Certification ECU (smart key ECU assembly)

  • Steering lock ECU (steering lock actuator assembly)

  • ID code box (immobiliser code ECU)

  • Wire harness or connector

WIRING DIAGRAM

A000856E23
*a ID Code Box (Immobiliser Code ECU)
*b Certification ECU (Smart Key ECU Assembly)
*c Steering Lock ECU (Steering Lock Actuator Assembly)
*d LIN Communication Line

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - EACH ECU)


    1. Disconnect the H58 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the H18 steering lock ECU (steering lock actuator assembly) connector.

    3. Disconnect the H15 ID code box (immobiliser code ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H58-17 (LIN) - H18-5 (LIN) Always Below 1 Ω
      H58-17 (LIN) - H15-2 (LIN1) Always Below 1 Ω
      H58-17 (LIN) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK DTC OUTPUT (STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY))


    1. Reconnect the H58 certification ECU (smart key ECU assembly) connector.

    2. Reconnect the H15 ID code box (immobiliser code ECU) connector.

    3. Clear the DTCs Click here.

    4. Recheck for DTCs.

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

    B

    REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY) Click here

    A

  3. CHECK DTC OUTPUT (ID CODE BOX (IMMOBILISER CODE ECU))


    1. Reconnect the H18 connector.

    2. Disconnect the H15 connector.

    3. Clear the DTCs Click here.

    4. Recheck for DTCs.

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

    A

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    B

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU)