B1244

LIGHTING (EXT): LIGHTING SYSTEM: B1244: Light Sensor Circuit Malfunction

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 (driver side junction block assembly). The main body ECU (driver side junction block assembly) 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) Select the following menu items: Body Electrical / Main Body / Data List.
(e) Read the display on 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 (DRIVER SIDE JUNCTION BLOCK ASSEMBLY)
2. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - AUTOMATIC LIGHT CONTROL SENSOR)
(a) for Manual A/C





(1) Disconnect the F3 automatic light control sensor connector.
(2) Disconnect the D49 main body ECU (driver side junction block assembly) connector.
(3) Measure the resistance according to the value(s) in the table below.
Standard Resistance:





Text in Illustration





(b) for Automatic A/C





(1) Disconnect the F4 automatic light control sensor connector.
(2) Disconnect the D49 main body ECU (driver side junction block assembly) connector.
(3) Measure the resistance according to the value(s) in the table below.
Standard Resistance:





Text in Illustration





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

3. INSPECT MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY)
(a) Reconnect the D49 main body ECU (driver side junction block assembly) connector.
(b) Measure the voltage and resistance according to the value(s) in the table below.





Text in Illustration





Standard Voltage:





Standard Resistance:






NG -- REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY)
OK -- Continue to next step.

4. INSPECT AUTOMATIC LIGHT CONTROL SENSOR
(a) for Manual A/C:





(1) Reconnect the F3 automatic light control sensor connector.
(2) Connect an oscilloscope to the automatic light control sensor connector.

Text in Illustration









(3) Check the waveform.
OK:





HINT: If the ambient light becomes brighter, width A becomes narrower.
(b) for Automatic A/C:





(1) Reconnect the F4 automatic light control sensor connector.
(2) Connect an oscilloscope to the automatic light control sensor connector.

Text in Illustration









(3) Check the waveform.
OK:





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

NG -- REPLACE AUTOMATIC LIGHT CONTROL SENSOR
OK -- REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY)