LIGHTING SYSTEM, Diagnostic DTC:B1244

DTC Code DTC Name
B1244 Light Sensor Circuit Malfunction

DESCRIPTION

The automatic light control sensor detects ambient light, converts it into an electrical signal, and outputs it to the main body ECU (network gateway ECU). The main body ECU (network gateway ECU) turns on or off the headlights and taillights according to the signal.

DTC No. DTC Detection Condition Trouble Area
B1244

  • Malfunction in automatic light control sensor.

  • Open or short in automatic light control sensor circuit.

  • Automatic light control sensor

  • Main body ECU (Network gateway ECU)

  • Harness or connector

WIRING DIAGRAM

A004JMWE12
*a Automatic Light Control Sensor
*b Main Body ECU (Network Gateway ECU)

PROCEDURE


  1. READ VALUE USING GTS (ILLUMINATION RATE INFO)


    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. Read the display on the GTS.

      Main Body
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Illumination Rate Info Illumination rate information / 0 ms to 99.99 ms Value is output according to ambient light levels -
      OK
      Normal condition listed above is displayed.
      Result
      Result Proceed to
      NG A
      OK B

    B

    REPLACE MAIN BODY ECU (NETWORK GATEWAY ECU) Click here

    A

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


    1. Disconnect the D6 main body ECU (network gateway ECU) connector.

    2. Disconnect the D45 automatic light control sensor connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      D6-13 (CLTE) - D45-6 (CLTE) Always Below 1 Ω
      D6-14 (CLTS) - D45-4 (CLTS) Always Below 1 Ω
      D6-15 (CLTB) - D45-3 (CLTB) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      D6-13 (CLTE) - Body ground Always 10 kΩ or higher
      D6-14 (CLTS) - Body ground Always 10 kΩ or higher
      D6-15 (CLTB) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK MAIN BODY ECU (NETWORK GATEWAY ECU)


    1. Reconnect the D6 main body ECU (network gateway ECU) connector.

    2. A004IV0E02
      Text in Illustration
      *a

      Component with harness connected

      (Main Body ECU (Network Gateway ECU))

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      D6-13 (CLTE) - D6-14 (CLTS) Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      D6-13 (CLTE) - Body ground Always 10 kΩ or higher

    NG

    REPLACE MAIN BODY ECU (NETWORK GATEWAY ECU) Click here

    OK

  4. INSPECT AUTOMATIC LIGHT CONTROL SENSOR


    1. Reconnect the automatic light control sensor Click here.

    2. Inspect the automatic light control sensor Click here.


    OK

    REPLACE MAIN BODY ECU (NETWORK GATEWAY ECU) Click here

    NG

    REPLACE AUTOMATIC LIGHT CONTROL SENSOR Click here