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

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

  • Malfunction in the automatic light control sensor.

  • Open or short in the automatic light control sensor circuit.

  • Automatic light control sensor

  • Main body ECU (multiplex network body ECU)

  • Harness or connector

WIRING DIAGRAM

A01VA58E05
*a Automatic Light Control Sensor
*b Main Body ECU (Multiplex Network Body ECU)

CAUTION / NOTICE / HINT

Note

When replacing the main body ECU (multiplex network body ECU), make sure to replace it with a new one.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs.

      Click here


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

    NEXT

  2. CHECK FOR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > Main Body > Clear DTCs
      Result
      Proceed to
      DTC B1244 output does not occur
      DTC B1244 output occur

    DTC B1244 output does not occur

    USE SIMULATION METHOD TO CHECK Click here

    DTC B1244 output occur

  3. READ VALUE USING GTS (AUTOMATIC LIGHT CONTROL SENSOR)


    1. Using the GTS, read the Data List.

      Click here


      Body Electrical > Main Body > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Illumination Rate Info Illumination rate information 0 ms. to 2162.65 ms. Value output according to ambient light levels -

      Body Electrical > Main Body > Data List
      Tester Display
      Illumination Rate Info
      OK
      The display is as specified in the normal condition column.
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

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


    1. Disconnect the G78 main body ECU (multiplex network body ECU) connector.

    2. Disconnect the G2 automatic light control sensor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G78-22 (CLTE) - G2-3 (CLTE) Always Below 1 Ω
      G78-21 (CLTS) - G2-5 (CLTS) Always Below 1 Ω
      G78-20 (CLTB) - G2-6 (CLTB) Always Below 1 Ω
      G78-22 (CLTE) - Body ground Always 10 kΩ or higher
      G78-21 (CLTS) - Body ground Always 10 kΩ or higher
      G78-20 (CLTB) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A01V8C1C06
      *a

      Component with harness connected

      (Main Body ECU [Multiplex Network Body ECU])

      Remove the instrument panel junction block assembly and main body ECU (multiplex network body ECU) as a unit with the connectors still connected.

      for LHD:

      Click here

      for RHD:

      Click here

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G78-20 (CLTB) - G78-22 (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) for LHD: REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here
    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) for RHD: REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    OK

  6. CHECK AUTOMATIC LIGHT CONTROL SENSOR


    1. Check the automatic light control sensor.

      Click here

      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPLACE AUTOMATIC LIGHT CONTROL SENSOR Click here