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

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

  • Certification ECU

  • Main body ECU

  • ID code box

  • Steering lock actuator assembly (Steering lock ECU)

  • Harness or connector

WIRING DIAGRAM

A01GWBWE01

INSPECTION PROCEDURE

Note

When using the intelligent tester with the power 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. CLEAR DTC


    1. Clear the DTC Click here.


    NEXT

  2. CHECK FOR DTC


    1. Recheck for DTC Click here.

      Result:
      Result Proceed to
      DTC B2785 output reoccurs A
      DTC B2785 output does not reoccur B

    B

    USE SIMULATION METHOD TO CHECK Click here

    A

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

    A01GYTOE01

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - BODY GROUND)

    A01GXUME01

    1. Reconnect the DA ECU connector.

    2. Disconnect the L15 ECU connector.

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

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

    NG

    CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BODY GROUND) Click here

    OK

    REPLACE CERTIFICATION ECU

  5. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BODY GROUND)

    A01H03ZE02

    1. Disconnect the DA ECU connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      DA-23 (LIN1) - Body ground Always 10 kΩ or higher
      Standard voltage
      Tester Connection Switch Condition Specified Condition
      DA-23 (LIN1) - Body ground Power switch on (IG) Below 1 V

    NG

    CLEAR DTC Click here

    OK

    REPLACE MAIN BODY ECU

  6. CLEAR DTC


    1. Reconnect the L15 ECU connector.

    2. Reconnect the DA ECU connector.

    3. Clear the DTC Click here.


    NEXT

  7. CHECK FOR DTC


    1. Disconnect the L33 ECU connector.

    2. Recheck for DTC Click here.

      Result:
      Result Proceed to
      DTC B2785 output reoccurs A
      DTC B2786 output occurs B

    B

    REPLACE STEERING LOCK ACTUATOR ASSEMBLY Click here

    A

  8. CLEAR DTC


    1. Reconnect the L33 ECU connector.

    2. Clear the DTC Click here.


    NEXT

  9. CHECK FOR DTC


    1. Disconnect the L32 box connector.

    2. Recheck for DTC Click here.

      Result:
      Result Proceed to
      DTC B2785 output reoccurs A
      DTC B2789 output occurs B

    B

    REPLACE ID CODE BOX

    A

    REPAIR OR REPLACE HARNESS OR CONNECTOR