Lexus IS250 · Service Manual BODY ELECTRICAL

B1244

Diagnostic trouble codes

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 light sensor
  2. Open or short of light sensor circuit
  1. Automatic light control sensor
  2. Wire harness or connector
  3. Main body ECU RH (Cowl side J/B RH)

WIRING DIAGRAM

E124321E01

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

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

    OK:
    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)
E110311E03

  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

  1. B109993E06
    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.

  1. B107499E03
    Connect the oscilloscope and check the waveform according the 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)


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