LIGHTING SYSTEM(w/ Automatic Headlight Beam Level Control System), Diagnostic DTC:B1244

DTC Code DTC Name
B1244 Light Sensor Circuit

DESCRIPTION

The automatic light control sensor detects ambient light. The sensor creates an electrical signal based on the amount of light detected, and sends the signal to the main body ECU (multiplex network body ECU). The main body ECU (multiplex network body ECU) turns on or off the headlights and taillights according to the signal.

DTC No. Detection Item DTC Detection Condition Trouble Area DTC Output from
B1244 Light Sensor Circuit

    Detection condition:

  • The ignition switch is ON.


    Malfunction status:

  • Either of the following conditions is met:


    • Malfunction in automatic light control sensor

    • Open or short in automatic light control sensor circuit


    Malfunction duration:

  • 5 seconds or more

  • Automatic light control sensor

  • Harness or connector

  • Main body ECU (multiplex network body ECU)

 Main body ECU (multiplex network body ECU)

WIRING DIAGRAM

B006YRCE01
*a Automatic Light Control Sensor
*b Main Body ECU (Multiplex Network Body ECU)

CAUTION / NOTICE / HINT

Note


  • The vehicle battery supplies power to the main body ECU (multiplex network body ECU) via the door control battery. Therefore, before performing this troubleshooting procedure, make sure to perform an on-vehicle inspection to confirm that the main body ECU (multiplex network body ECU) power source circuit is normal.*1

    Click here

  • Before replacing the main body ECU (multiplex network body ECU), refer to Service Bulletin.*2


    • *1: w/ Door Control Battery

    • *2: w/ Smart Entry and Start System

PROCEDURE


  1. CLEAR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Main Body / Trouble Codes.

    5. Clear the DTCs.


      Body Electrical > Main Body > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  2. CHECK FOR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Wait 10 seconds or more.

    4. Turn the GTS on.

    5. Enter the following menus: Body Electrical / Main Body / Trouble Codes.

    6. Check for DTCs.


      Body Electrical > Main Body > Trouble Codes
      OK
      DTC B1244 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  3. READ VALUE USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Main Body / Data List.

    5. According to the display on the GTS, read the Data List and check that the value of Light Sensor Illuminance changes while performing the following:


      1. Cover the automatic light control sensor with an opaque object.

      2. Slowly move the opaque object to uncover and then cover the automatic light control sensor.


        Body Electrical > Main Body > Data List
        Tester Display Measurement Item Range Normal Condition Diagnostic Note
        Light Sensor Illuminance Light control sensor illuminance 0 to 8191 lx or SensorFail Value is output according to ambient light level -

        Body Electrical > Main Body > Data List
        Tester Display
        Light Sensor Illuminance
        OK
        The value changes according to the amount the automatic light control sensor is covered.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    NG

  4. CHECK HARNESS AND CONNECTOR (AUTOMATIC LIGHT CONTROL SENSOR - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))


    1. Disconnect the M1 automatic light control sensor connector.

    2. Disconnect the K52 main body ECU (multiplex network body ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      M1-1 (CLTB) - K52-23 (CLTB) Always Below 1 Ω
      M1-4 (CLTS) - K52-24 (CLTS) Always Below 1 Ω
      M1-2 (CLTE) - K52-25 (CLTE) Always Below 1 Ω
      M1-1 (CLTB) or K52-23 (CLTB) - Body ground Always 10 kΩ or higher
      M1-4 (CLTS) or K52-24 (CLTS) - Body ground Always 10 kΩ or higher
      M1-2 (CLTE) or K52-25 (CLTE) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

    B006WZVC02
    *a

    Component with harness connected

    (Main Body ECU (Multiplex Network Body ECU))

    1. Connect the K52 main body ECU (multiplex network body ECU) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      K52-23 (CLTB) - K52-25 (CLTE) Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    OK

  6. INSPECT AUTOMATIC LIGHT CONTROL SENSOR


    1. Inspect the automatic light control sensor.

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    NG

    REPLACE AUTOMATIC LIGHT CONTROL SENSOR Click here