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

DTC No. DTC Detection Condition Trouble Area
B1244

  • 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

A005KUNE08
*a AUTOMATIC LIGHT CONTROL SENSOR
*b MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

CAUTION / NOTICE / HINT

Note

Initialization is necessary when the main body ECU (multiplex network body ECU) is replaced Click here.

PROCEDURE


  1. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC B1244 output does not occur.
      Result
      Result Proceed to
      NG A
      OK B

    B

    USE SIMULATION METHOD TO CHECK Click here

    A

  2. READ VALUE USING INTELLIGENT TESTER (ILLUMINATION RATE INFO)


    1. Using the intelligent tester, read the Data List Click here.

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

    B

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

    A

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


    1. Disconnect the F76 main body ECU (multiplex network body ECU) connector.

    2. Disconnect the F73 automatic light control sensor connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      F76-22 (CLTE) - F73-5 (CLTE) Always Below 1 Ω
      F76-21 (CLTS) - F73-4 (CLTS) Always Below 1 Ω
      F76-20 (CLTB) - F73-3 (CLTB) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      F76-22 (CLTE) - Body ground Always 10 kΩ or higher
      F76-21 (CLTS) - Body ground Always 10 kΩ or higher
      K-20 (CLTB) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

    A005GSAE02
    Text in Illustration
    *a

    Component with harness connected

    (Main Body ECU (Multiplex Network Body ECU))

    1. Reconnect the F76 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 Switch Condition Specified Condition
      F76-20 (CLTB) - F76-22 (CLTE) Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      F76-22 (CLTE) - Body ground Always Below 1 Ω

    NG

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

    OK

  5. INSPECT AUTOMATIC LIGHT CONTROL SENSOR


    1. Reconnect the automatic light control sensor.

    2. Inspect 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