LIGHTING SYSTEM, Diagnostic DTC:B124D

DTC Code DTC Name
B124D Lost Communication with AFS LIN

DESCRIPTION

The DTC is stored when the main body ECU (driver side junction block assembly) detects malfunctions in the LIN communication system.

DTC No. DTC Detection Condition Trouble Area
B124D Malfunction in LIN communication system

  • Inner rear view mirror assembly

  • Harness or connector

  • AFS ECU (headlight swivel ECU assembly)

WIRING DIAGRAM

A01ELLHE02

INSPECTION PROCEDURE

Note

First perform the communication function inspections in How to Proceed with Troubleshooting to confirm that there are no CAN communication malfunctions before troubleshooting this symptom.

PROCEDURE


  1. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC B124D is not output.

    NG

    CHECK HARNESS AND CONNECTOR (AFS ECU - INNER REAR VIEW MIRROR ASSEMBLY) Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  2. CHECK HARNESS AND CONNECTOR (AFS ECU - INNER REAR VIEW MIRROR ASSEMBLY)


    1. Disconnect the D44 AFS ECU (headlight swivel ECU assembly) connector.

    2. Disconnect the P12 inner rear view mirror assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D44-10 (SMR) - P12-3 (LIN) Always Below 1 Ω
      P12-3 (LIN) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT AFS ECU (HEADLIGHT SWIVEL ECU ASSEMBLY)


    1. Reconnect the D44 AFS ECU (headlight swivel ECU assembly) connector.

    2. A01EK89E07

      Connect an oscilloscope to the P12 inner rear view mirror assembly connector.

    3. A01EMN0E01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Inner Rear View Mirror Assembly)

      Check the waveform.

      OK
      Tester Connection Tool Setting Condition Specified Condition
      P12-3 (LIN) - P12-2 (E) 2 V/DIV., 20 ms./DIV. Ignition switch ON Correct waveform is as shown

    NG

    REPLACE AFS ECU (HEADLIGHT SWIVEL ECU ASSEMBLY) Click here

    OK

    REPLACE INNER REAR VIEW MIRROR ASSEMBLY Click here