LIGHTING SYSTEM, Diagnostic DTC:B1244

DTC Code DTC Name
B1244 Light Sensor Circuit Malfunction

DESCRIPTION

Tech Tips

Light sensor refers to the rain sensor.

This DTC is stored when a failure in the rain sensor circuit is detected.

DTC Code DTC Detection Condition Trouble Area
B1244

Either condition is met:


  • A malfunction in the rain sensor.

  • An open or short in the rain sensor circuit.

  • Rain sensor (automatic light control sensor)

  • Main body ECU (instrument panel junction block assembly)

  • Windshield wiper relay assembly

  • Harness or connector

WIRING DIAGRAM

A01IREKE04

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC B1244 output does not occur.

    NG

    CHECK AUTOMATIC WIPER FUNCTION Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  2. CHECK AUTOMATIC WIPER FUNCTION


    1. Check the automatic wiper system.


      1. Turn the wiper switch to the AUTO position.

      2. With the rain sensor installed to the windshield, sprinkle water on the windshield around the rain sensor. Check if the wipers operate.

        OK
        The wipers operate.

    NG

    GO TO WIPER AND WASHER SYSTEM Click here

    OK

  3. CHECK AUTOMATIC LIGHT CONTROL FUNCTION


    1. Check the automatic light control system.


      1. Turn the light control switch to the AUTO position.

      2. With the rain sensor installed to the windshield, cover the rain sensor with a hand. Check if the headlights operate.

        OK
        The headlights operate.

        Tech Tips

        The sensitivity of the automatic light control system can be adjusted using the customize function. Make sure that the sensitivity setting is NORMAL before performing this check.


    NG

    CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - WINDSHIELD WIPER RELAY ASSEMBLY) Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  4. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - WINDSHIELD WIPER RELAY ASSEMBLY)


    1. A01IR9GE03
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Windshield Wiper Relay)
      *2

      Front view of wire harness connector

      (to Main Body ECU)

      Disconnect the H56 windshield wiper relay connector and H80 main body ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H80-15 (CLTS) - H56-23 (SF) Always Below 1 Ω
      H80-15 (CLTS) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK WINDSHIELD WIPER RELAY ASSEMBLY


    1. A01IRRTE01

      Reconnect the H56 windshield wiper relay connector and H80 main body ECU connector.

    2. Connect an oscilloscope to the rain sensor connector.

    3. Check the waveform.

      OK
      Tester Connection Switch Condition Specified Condition
      H56-23 (SF) - Body ground Ignition switch ON Pulse generation (See waveform 1)

      1. A01ITUSE01
        Text in Illustration
        *1

        Component with harness connected

        (Windshield Wiper Relay)

        Waveform 1

        Item Content
        Tool setting 5 V/DIV., 10 ms./DIV.

        Tech Tips

        If the ambient light becomes brighter, width A becomes narrower.

        Result
        Result Proceed to
        OK A
        NG (for LHD) B
        NG (for RHD) C

    B

    REPLACE WINDSHIELD WIPER RELAY ASSEMBLY Click here

    C

    REPLACE WINDSHIELD WIPER RELAY ASSEMBLY Click here

    A

    REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)