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. The main body ECU turns on or off the headlights and taillights according to the signal.

DTC No. DTC Detecting Condition Trouble Area
B1244

  • Malfunction in automatic light control sensor

  • Open or short in automatic light control sensor circuit

  • Automatic light control sensor

  • Harness or connector

  • Main body ECU (Instrument panel junction block)

WIRING DIAGRAM

A017BB0E12

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch on (IG).

    3. Turn the intelligent tester on.

    4. Select the following menu items: Body Electrical / Main Body / Data List.

    5. Read the display on the intelligent tester.

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

    NG

    CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - AUTOMATIC LIGHT CONTROL SENSOR) Click here

    OK

    REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)

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


    1. A017EQ1E13

      Disconnect the F1 automatic light control sensor connector.

    2. Disconnect the D6 main body ECU connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D6-18 (CLTE) - F1-3 (CLTE) Always Below 1 Ω
      D6-19 (CLTS) - F1-5 (CLTS) Always Below 1 Ω
      D6-20 (CLTB) - F1-6 (CLTB) Always Below 1 Ω
      D6-18 (CLTE) - Body ground Always 10 kΩ or higher
      D6-19 (CLTS) - Body ground Always 10 kΩ or higher
      D6-20 (CLTB) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY )


    1. Reconnect the main body ECU connector.

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

      A017DZQE04
      Standard voltage
      Tester Connection Condition Specified Condition
      D6-20 (CLTB) - D6-18 (CLTE) Ignition switch off Below 1 V
      Ignition switch on (IG) 11 to 14 V
      Standard resistance
      Tester Connection Condition Specified Condition
      D6-18 (CLTE) - Body ground Always Below 1 Ω

    NG

    REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)

    OK

  4. INSPECT AUTOMATIC LIGHT CONTROL SENSOR


    1. A017G8GE01

      Reconnect the automatic light control sensor connector.

    2. Connect an oscilloscope to the automatic light control sensor connector.

    3. A017BDQE01

      Check the waveform.

      OK
      Tester Connection Tool Setting Condition Specified Condition
      F1-3 (CLTE) - F1-5 (CLTS) 5 V/DIV., 5 ms./DIV. Ignition switch on (IG), light control switch in AUTO Correct waveform is as shown

      Tech Tips

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


    NG

    REPLACE AUTOMATIC LIGHT CONTROL SENSOR

    OK

    REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)