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 |
How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT
HINT:
Use the following procedure to troubleshoot the front power seat control
system (w/ Memory).
*: Use the Techstream.
PROCEDURE
1.
VEHICLE BROUGHT TO WORKSHOP
...
Diagnostic Trouble Code Chart
DIAGNOSTIC TROUBLE CODE CHART
HINT:
If a trouble code is stored during the DTC check, inspect the trouble areas listed
for that code. For details of the code, refer to the "See page" below.
Certification ECU (Smart Key ECU Assembly)
...
Problem Symptoms Table
PROBLEM SYMPTOMS TABLE
HINT:
Use the table below to help determine the cause of problem symptoms.
If multiple suspected areas are listed, the potential causes of the symptoms
are listed in order of probability in the "Suspected Area" ...