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.
DTC No. |
DTC Detecting Condition |
Trouble Area |
---|---|---|
B1244 |
|
|
WIRING DIAGRAM
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
Tester Display |
Measurement Item/Range |
Normal Condition |
Diagnostic Note |
---|---|---|---|
Illumination Rate Info |
Illumination rate information/0 ms to 99.99 ms |
Value is output according to ambient light levels |
- |
OK:
Normal condition listed above is displayed.
OK | ![]() |
REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY) |
|
2. |
CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - AUTOMATIC LIGHT CONTROL SENSOR) |
(a) Disconnect the F4 automatic light control sensor connector.
(b) Disconnect the D49 main body ECU (driver side junction block assembly) connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
D49-18 (CLTE) - F4-3 (CLTE) |
Always |
Below 1 Ω |
D49-19 (CLTS) - F4-5 (CLTS) |
Always |
Below 1 Ω |
D49-20 (CLTB) - F4-6 (CLTB) |
Always |
Below 1 Ω |
D49-18 (CLTE) - Body ground |
Always |
10 kΩ or higher |
D49-19 (CLTS) - Body ground |
Always |
10 kΩ or higher |
D49-20 (CLTB) - Body ground |
Always |
10 kΩ or higher |
NG | ![]() |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
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.
*1 |
Component with harness connected (Main Body ECU (Driver Side Junction Block Assembly)) |
- |
- |
Standard Voltage:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
D49-20 (CLTB) - D49-18 (CLTE) |
Ignition switch off |
Below 1 V |
Ignition switch ON |
11 to 14 V |
Standard Resistance:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
D49-18 (CLTE) - Body ground |
Always |
Below 1 Ω |
NG | ![]() |
REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY) |
|
4. |
INSPECT AUTOMATIC LIGHT CONTROL SENSOR |
(a) Reconnect the F4 automatic light control sensor connector. |
|
(b) Connect an oscilloscope to the automatic light control sensor connector.
Text in Illustration
*1 |
Component with harness connected (Automatic Light Control Sensor) |
(c) Check the waveform. OK:
HINT: If the ambient light becomes brighter, width A becomes narrower. |
|
OK | ![]() |
REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY) |
NG | ![]() |
REPLACE AUTOMATIC LIGHT CONTROL SENSOR |
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(a) Turn the ignition switch off.
(b) Connect the Techstream to the DLC3.
(c) Turn the ignition switch to ON.
(d) Turn the Techstream on.
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