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

E240319E05

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. Check the DTCs.

      Click here

      Body Electrical > Main Body > Trouble Codes

    Result

    Proceed to

    DTC B1244 output does not occur

    DTC B1244 output occurs
    DTC B1244 output does not occur

    USE SIMULATION METHOD TO CHECK

    Click hereClick hereClick here

    DTC B1244 output occurs

  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:

    Click here

    for RHD:

    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. E203228C06

      *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)

      Power switch off

      Below 1 V

      Power switch on (IG)

      11 to 14 V

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

    for LHD:

    Click here

    for RHD:

    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:

    Click here

    for RHD:

    Click here

    NG

    REPLACE AUTOMATIC LIGHT CONTROL SENSOR

    Click here