Dtc B1244 Light Sensor Circuit Malfunction

Body Electrical. Lexus Is250, Is220D. Gse20 Ale20
Lighting. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK AUTOMATIC LIGHT CONTROL SENSOR (OPERATION)

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

CHECK AUTOMATIC LIGHT CONTROL SENSOR

DTC B1244 Light Sensor Circuit Malfunction


DESCRIPTION

This DTC is output when a failure of the automatic light control sensor circuit is detected.

DTC No.
DTC Detection Condition
Trouble Area
B1244
  1. Malfunction of automatic light control sensor
  2. Open or short in automatic light control sensor circuit
  1. Automatic light control sensor
  2. Wire harness or connector
  3. Main body ECU RH (Cowl side J/B RH)

WIRING DIAGRAM


Lexus Is250, Is220D. Gse20 Ale20.Lighting.Lighting System. Dtc B1244 Light Sensor Circuit Malfunction


INSPECTION PROCEDURE

1.CHECK AUTOMATIC LIGHT CONTROL SENSOR (OPERATION)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG).

  1. Turn the intelligent tester main switch on.

  1. Select the "DATA LIST" on the intelligent tester.

    DATA LIST: Body (Main Body ECU RH)
    Item
    		Measurement Item / Display (Range)
    		Normal Condition
    Illumination Rate Info
    		Illumination information / 10 to 99.99 ms
    		0.8 to 22 ms

  1. The value of the illumination rate should change in the following range when light shines on the automatic light control sensor or when the automatic light control sensor is covered.

    OK:
    0.8 to 22 ms
    HINT:
    This is the time taken for the automatic light control sensor to generate one cycle of frequency according to the brightness.


OK
REPLACE MAIN BODY ECU RH (COWL SIDE J/B RH)
NG


2.CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH - AUTOMATIC LIGHT CONTROL SENSOR)
Lexus Is250, Is220D. Gse20 Ale20.Lighting.Lighting System. Dtc B1244 Light Sensor Circuit Malfunction

  1. Disconnect the J74 main body ECU RH connector.

  1. Disconnect the K1 automatic light control sensor connector.

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

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    J74-6 (CLTB) - K1-6 (CLTB)
    		Always
    		Below 1 Ω
    J74-5 (CLTS) - K1-5 (CLTS)
    		Always
    		Below 1 Ω
    J74-4 (CLTE) - K1-3 (CLTE)
    		Always
    		Below 1 Ω
    J74-6 (CLTB) - Body ground
    		Always
    		10 kΩ or higher
    J74-5 (CLTS) - Body ground
    		Always
    		10 kΩ or higher
    J74-4 (CLTE) - Body ground
    		Always
    		10 kΩ or higher

  1. Connect the 2 connectors.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.CHECK AUTOMATIC LIGHT CONTROL SENSOR


    Lexus Is250, Is220D. Gse20 Ale20.Lighting.Lighting System. Dtc B1244 Light Sensor Circuit Malfunction

  1. Disconnect the automatic light control sensor.

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

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    K1-3 (CLTE) - Body ground
    		Always
    		Below 1 Ω

  1. Connect the voltmeter's positive (+) lead to terminal 6 and the negative (-) lead to terminal 3.

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

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    K1-3 (CLTE) - K1-6 (CLTB)
    		Engine switch on (IG)
    		10 to 14 V

  1. Connect the K1 automatic light control sensor connector.



    Lexus Is250, Is220D. Gse20 Ale20.Lighting.Lighting System. Dtc B1244 Light Sensor Circuit Malfunction

  1. Connect the oscilloscope and check the waveform according to the table below.

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    		Tester Range
    K1-3 (CLTE) - K1-5 (CLTS)
    		Engine switch on (IG), Headlight dimmer switch in AUTO
    		Correct waveform is as shown
    		5 V Division, 5 msec/Division
    If the ambient light becomes brighter, width A becomes narrower.


NG
REPLACE AUTOMATIC LIGHT CONTROL SENSOR
OK

REPLACE MAIN BODY ECU RH (COWL SIDE J/B RH)