The automatic light control sensor detects ambient light. The sensor creates an electrical signal based on the amount of light detected, and sends the signal 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.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | DTC Output from |
|---|---|---|---|---|
| B124400 | Light Sensor Circuit Malfunction | Detection condition:
The ignition switch is ON Malfunction status:
Either of the following conditions is met: -
Malfunction in automatic light control sensor -
Open or short in automatic light control sensor circuit Malfunction duration:
5 seconds or more |
·
Automatic light control sensor ·
Harness or connector ·
Main body ECU (multiplex network body ECU) |
Main Body |
Before replacing the main body ECU (multiplex network body ECU), refer to Service Bulletin.
Clear the DTCs.
| Proceed to |
|---|
| NEXT |
NEXT
Turn the ignition switch to ON.
Wait 5 seconds or more.
Check for DTCs.
DTC B124400 is not output.
| Proceed to |
|---|
| OK |
| NG |
OK
NG
According to the display on the GTS, read the Data List and check that the value of Light Sensor Illuminance changes while performing the following:
Cover the automatic light control sensor with an opaque object.
Slowly move the opaque object to uncover and then cover the automatic light control sensor.
| Tester Display | Measurement Item | Range | Normal Condition | Diagnostic Note |
|---|---|---|---|---|
| Light Sensor Illuminance | Light control sensor illuminance | 0 to 8191 lx or SensorFail | Value is output according to ambient light level | The displayed value is "0" when no light is detected. |
| Tester Display |
|---|
| Light Sensor Illuminance |
The value changes according to the amount the automatic light control sensor is covered.
| Proceed to |
|---|
| OK |
| NG |
OK
NG
Disconnect the H1 automatic light control sensor connector.
Disconnect the G169 main body ECU (multiplex network body ECU) connector.
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| H1-1 (CLTB) - G169-8 (CLTB) | Always | Below 1 Ω |
| H1-4 (CLTS) - G169-20 (CLTS) | Always | Below 1 Ω |
| H1-2 (CLTE) - G169-21 (CLTE) | Always | Below 1 Ω |
| H1-1 (CLTB) or G169-8 (CLTB) - Body ground | Always | 10 kΩ or higher |
| H1-4 (CLTS) or G169-20 (CLTS) - Body ground | Always | 10 kΩ or higher |
| H1-2 (CLTE) or G169-21 (CLTE) - Body ground | Always | 10 kΩ or higher |
| Proceed to |
|---|
| OK |
| NG |
OK
NG
| *a | Component with harness connected
(Main Body ECU (Multiplex Network Body ECU)) |
Measure the voltage according to the value(s) in the table below.
| Tester Connection | Switch Condition | Specified Condition |
|---|---|---|
| G169-8 (CLTB) - G169-21 (CLTE) | Ignition switch ON | 11 to 14 V |
| Proceed to |
|---|
| OK |
| NG |
OK
NG
| Proceed to |
|---|
| OK |
| NG |
OK
NG