B1244

LIGHTING: LIGHTING SYSTEM: B1244: Light Sensor Circuit Malfunction
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 on or off the headlights and taillights according to the signal.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Main Body / Data List.

(e) Read the display on the Techstream.

Main Body:





OK:

Normal condition listed above is displayed.

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

OK -- REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)

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

(a) for Manual Air Conditioning System

(1) Disconnect the F2 automatic light control sensor connector.





(2) Disconnect the D7 main body ECU connector.

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

Standard resistance:





(b) for Automatic Air Conditioning System

(1) Disconnect the F1 automatic light control sensor connector.





(2) Disconnect the D7 main body ECU connector.

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

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

3. CHECK MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

(a) Remove the main body ECU with its connectors still connected.

(b) Measure the voltage and resistance according to the value(s) in the table below.





Standard voltage:





Standard resistance:





NG -- REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)
OK -- Continue to next step.

4. INSPECT AUTOMATIC LIGHT CONTROL SENSOR

(a) for Manual Air Conditioning System

(1) Remove the automatic light control sensor with its connectors still connected.





(2) Connect an oscilloscope to the automatic light control sensor connector.

(3) Check the waveform.

OK:









HINT
If the ambient light becomes brighter, width A becomes narrower.

(b) for Automatic Air Conditioning System

(1) Remove the automatic light control sensor with its connectors still connected.





(2) Connect an oscilloscope to the automatic light control sensor connector.

(3) Check the waveform.

OK:









HINT
If the ambient light becomes brighter, width A becomes narrower.

NG -- REPLACE AUTOMATIC LIGHT CONTROL SENSOR Removal

OK -- REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)