B1244

LIGHTING (EXT): 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 (multiplex network body ECU). The main body ECU (multiplex network 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 engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menu items: 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 (MULTIPLEX NETWORK BODY ECU)

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

(a) Disconnect the H3 automatic light control sensor connector.

(b) Disconnect the F13 main body ECU (multiplex network body ECU) connector.

(c) 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 (MULTIPLEX NETWORK BODY ECU)

(a) Reconnect the F13 main body ECU (multiplex network body ECU) connector.

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

Standard Voltage:

Standard Resistance:

Text in Illustration

NG -- REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)
OK -- Continue to next step.

4. INSPECT AUTOMATIC LIGHT CONTROL SENSOR

(a) Reconnect the H3 automatic light control sensor connector.

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

Text in Illustration

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

NG -- REPLACE AUTOMATIC LIGHT CONTROL SENSOR

OK -- REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)