Dtc B1244 Light Sensor Circuit Malfunction


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK FOR DTC

READ VALUE USING INTELLIGENT TESTER (AUTOMATIC LIGHT CONTROL SENSOR)

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

CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

CHECK AUTOMATIC LIGHT CONTROL SENSOR

DTC 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
  1. Malfunction in the automatic light control sensor.
  2. Open or short in the automatic light control sensor circuit.
  1. Automatic light control sensor
  2. Main body ECU (multiplex network body ECU)
  3. Harness or connector

WIRING DIAGRAM


Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Lighting (Ext).Lighting System. Dtc B1244 Light Sensor Circuit Malfunction


INSPECTION PROCEDURE

1.CHECK FOR DTC

  1. Clear the DTCs (LandCruiser RM000000PKT0AFX.html).

  1. Check for DTCs (LandCruiser RM000000PKT0AFX.html).

    OK:
    DTC B1244 output does not occur.


NG
Go to step 2
OK

USE SIMULATION METHOD TO CHECK (LandCruiser RM000003YMI00MX.html)

2.READ VALUE USING INTELLIGENT TESTER (AUTOMATIC LIGHT CONTROL SENSOR)

  1. Using the intelligent tester, read the Data List (LandCruiser RM000000PKV0J6X.html).

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


NG
Go to step 3
OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (LandCruiser RM000003WBO05FX.html)

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

  1. Disconnect the G64 main body ECU connector.

  1. Disconnect the H19 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
    G64-22 (CLTE) - H19-3 (CLTE)
    		Always
    		Below 1 Ω
    G64-21 (CLTS) - H19-5 (CLTS)
    		Always
    		Below 1 Ω
    G64-20 (CLTB) - H19-6 (CLTB)
    		Always
    		Below 1 Ω
    G64-22 (CLTE) - Body ground
    		Always
    		10 kΩ or higher
    G64-21 (CLTS) - Body ground
    		Always
    		10 kΩ or higher
    G64-20 (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)


    Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Lighting (Ext).Lighting System. Dtc B1244 Light Sensor Circuit Malfunction

  1. Reconnect the G64 main body ECU connector.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    G64-20 (CLTB) - G64-22 (CLTE)
    		Ignition switch off
    		Below 1 V
    Ignition switch ON and headlight dimmer switch in AUTO position
    		11 to 14 V
    Text in Illustration
    *a
    		Component with harness connected
    (Main Body ECU)


NG
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (LandCruiser RM000003WBO05FX.html)
OK


5.CHECK AUTOMATIC LIGHT CONTROL SENSOR


    Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Lighting (Ext).Lighting System. Dtc B1244 Light Sensor Circuit Malfunction

  1. Reconnect the H19 automatic light control sensor connector.

  1. Connect an oscilloscope to the automatic light control sensor connector.

    Text in Illustration
    *a
    		Component with harness connected
    (Automatic Light Control Sensor)


    Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Lighting (Ext).Lighting System. Dtc B1244 Light Sensor Circuit Malfunction

  1. Check the waveform.

    OK:
    Tester Connection
    		Tool Setting
    		Switch Condition
    		Specified Condition
    H19-5 (CLTS) - H19-3 (CLTE)
    		5 V/DIV., 5 ms./DIV.
    		Ignition switch ON
    Headlight dimmer switch AUTO Automatic light control sensor covered with a hand → Automatic light control sensor exposed to ambient light
    		Correct waveform is as shown
    HINT:
    When the ambient light becomes brighter, width A becomes narrower.


NG
REPLACE AUTOMATIC LIGHT CONTROL SENSOR (LandCruiser RM00000408201RX.html)
OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (LandCruiser RM000003WBO05FX.html)