LIGHTING SYSTEM, Diagnostic DTC:B1244

DTC Code DTC Name
B1244 Light Sensor Circuit Malfunction

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
B1244 Light Sensor Circuit Malfunction

  • 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 (multiplex network body ECU)

WIRING DIAGRAM

A01TCL7E09
*a Automatic Light Control Sensor
*b Main Body ECU (Multiplex Network Body ECU)

PROCEDURE


  1. 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. Read the display on the GTS.


      Body Electrical > Main Body > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Illumination Rate Info Illumination rate information 0.00 ms. to 2162.65 ms. Value is output according to ambient light level -

      Body Electrical > Main Body > Data List
      Tester Display
      Illumination Rate Info
      OK
      Normal condition listed above is displayed.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) for LHD: Click here
    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) for RHD: Click here

    NG

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


    1. Disconnect the F2 automatic light control sensor connector.

    2. Disconnect the E22 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
      E22-22 (CLTE) - F2-3 (CLTE) Always Below 1 Ω
      E22-21 (CLTS) - F2-4 (CLTS) Always Below 1 Ω
      E22-20 (CLTB) - F2-1 (CLTB) Always Below 1 Ω
      E22-22 (CLTE) - Body ground Always 10 kΩ or higher
      E22-21 (CLTS) - Body ground Always 10 kΩ or higher
      E22-20 (CLTB) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A01T9FQC10
      *a

      Component with harness connected

      (Main Body ECU (Multiplex Network Body ECU))

      Reconnect the E22 main body ECU (multiplex network body ECU) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      E22-20 (CLTB) - E22-22 (CLTE) Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      E22-22 (CLTE) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) for LHD: Click here
    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) for RHD: Click here

    OK

  4. INSPECT AUTOMATIC LIGHT CONTROL SENSOR


    1. A01TCGAC02
      *a

      Component with harness connected

      (Automatic Light Control Sensor)

      Reconnect the F2 automatic light control sensor connector.

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

    3. A01TDEKN01

      Check the waveform.

      OK
      Tester Connection Tool Setting Condition Specified Condition
      F2-3 (CLTE) - F2-4 (CLTS) 5 V/DIV., 5 ms./DIV. Ignition switch ON, light control switch in AUTO position Correct waveform is as shown

      Tech Tips

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

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) for LHD: Click here
    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) for RHD: Click here

    NG

    REPLACE AUTOMATIC LIGHT CONTROL SENSOR Click here