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 the headlights and taillights on or off according to the signal.

DTC Code DTC Detection Condition Trouble Area
B1244

Either of the following conditions is met:


  • Malfunction in automatic light control sensor.

  • Open or short in automatic light control sensor circuit.

  • Automatic light control sensor

  • Main body ECU (multiplex network body ECU)

  • Harness or connector

WIRING DIAGRAM

A000PFNE01
*a Automatic Light Control Sensor
*b Main Body ECU (Multiplex Network Body ECU)

CAUTION / NOTICE / HINT

Note


  • Recognition code registration is necessary when replacing the main body ECU (multiplex network body ECU).

  • If the main body ECU (multiplex network body ECU) is replaced, refer to the Service Bulletin.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs Click here.

      OK
      DTC B1244 output does not occur.

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

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


    1. Using the GTS, read the Data List Click here.

      Main Body
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Illumination Rate Info Light control sensor illuminance / 0 to 65535 lx Value is output according to ambient light level -
      OK
      Normal condition listed above is displayed.

    OK

    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 N12 main body ECU connector.

    2. Disconnect the O1 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
      N12-22 (CLTE) - O1-3 (CLTE) Always Below 1 Ω
      N12-21 (CLTS) - O1-5 (CLTS) Always Below 1 Ω
      N12-20 (CLTB) - O1-6 (CLTB) Always Below 1 Ω
      N12-22 (CLTE) - Body ground Always 10 kΩ or higher
      N12-21 (CLTS) - Body ground Always 10 kΩ or higher
      N12-20 (CLTB) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A000S5FE03
      Text in Illustration
      *a

      Component with harness connected

      (Main Body ECU [Multiplex Network Body ECU])

      Remove the main body ECU (multiplex network body ECU) with the connector(s) still connected Click here.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      N12-20 (CLTB) - N12-22 (CLTE) Power switch off Below 1 V
      Power switch on (IG) 11 to 14 V

    NG

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    OK

  6. INSPECT AUTOMATIC LIGHT CONTROL SENSOR


    1. Check the automatic light control sensor Click here.


    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    NG

    REPLACE AUTOMATIC LIGHT CONTROL SENSOR Click here