RM38N0EC _59 Vehicle Exterior _111834 LIGHTING (EXT) _0499887 LIGHTING SYSTEM C

LIGHTING (EXT)  LIGHTING SYSTEM  B124400  Light Sensor Circuit Malfunction  


DESCRIPTION

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

WIRING DIAGRAM

E367076E43
0.323,3.635 0.635,3.833 0.313,0.198 10 false E74 0.323,3.813 2.469,4.125 2.146,0.313 10 false Automatic Light Control Sensor 2.01,0.969 2.323,1.167 0.313,0.198 10 false 1 2.021,2.063 2.333,2.26 0.313,0.198 10 false 4 2.021,2.729 2.333,2.927 0.313,0.198 10 false 2 1.552,0.958 2.177,1.208 0.625,0.25 10 false CLTB 1.583,2.74 2.208,2.99 0.625,0.25 10 false CLTE 1.583,2.073 2.208,2.323 0.625,0.25 10 false CLTS 4.865,0.969 5.49,1.219 0.625,0.25 10 false CLTB 4.854,2.052 5.479,2.302 0.625,0.25 10 false CLTS 4.854,2.729 5.479,2.979 0.625,0.25 10 false CLTE 4.656,0.948 4.969,1.146 0.313,0.198 10 false 8 4.615,2.031 4.927,2.229 0.313,0.198 10 false 20 4.615,2.719 4.927,2.917 0.313,0.198 10 false 21 4.969,3.635 5.281,3.833 0.313,0.198 10 false E37 4.979,3.813 6.625,4.25 1.646,0.438 10 false Main Body ECU (Multiplex Network Body ECU) 5.271,1.188 5.563,1.375 0.292,0.188 10 false +B

CAUTION / NOTICE / HINT

NOTICE:

Before replacing the main body ECU (multiplex network body ECU), refer to Service Bulletin.


PROCEDURE

1.CLEAR DTC
a.

Clear the DTCs.

Body Electrical > Main Body > Clear DTCs
50002 449

Result:
Proceed to
NEXT



NEXT

2.CHECK FOR DTC
2.CHECK FOR DTC
a.

Turn the ignition switch to ON.


b.

Wait 10 seconds or more.


c.

Check for DTCs.

Body Electrical > Main Body > Trouble Codes
50001 449
OK:

DTC B124400 is not output.



Result:
Proceed to
OK
NG



OK

USE SIMULATION METHOD TO CHECK

Click hereGeneral>INTRODUCTION>HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS>HOW TO PROCEED WITH TROUBLESHOOTING


NG

3.READ VALUE USING GTS
3.READ VALUE USING GTS
a.

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:

i.

Cover the automatic light control sensor with an opaque object.


ii.

Slowly move the opaque object to uncover and then cover the automatic light control sensor.

Body Electrical > Main Body > Data List
Tester Display Measurement Item Normal Condition Reference Value Diagnostic Note
Light Sensor Illuminance Automatic 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.
Body Electrical > Main Body > Data List
Tester Display
Light Sensor Illuminance
50003 449 113
OK:

The value changes according to the amount the automatic light control sensor is covered.




Result:
Proceed to
OK
NG



OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

Click herePower Source / Network>POWER DISTRIBUTION>MAIN BODY ECU>REMOVAL


NG

4.CHECK HARNESS AND CONNECTOR (AUTOMATIC LIGHT CONTROL SENSOR - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))
4.CHECK HARNESS AND CONNECTOR (AUTOMATIC LIGHT CONTROL SENSOR - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))
a.

Disconnect the E74 automatic light control sensor connector.


b.

Disconnect the E37 main body ECU (multiplex network body ECU) connector.


c.

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

Standard Resistance:
Tester Connection Condition Specified Condition

Click Location & Routing(E74,E37)Location & Routing

Click Connector(E74)Instrument Panel>Instrument Panel Wire / Radio Wiring Sub-Assy / Telephone Computer Wire>Automatic Light Control Sensor

Click Connector(E37)Instrument Panel>Instrument Panel Wire / Radio Wiring Sub-Assy / Telephone Computer Wire>Multiplex Network Body ECU

E74-1 (CLTB) - E37-8 (CLTB) Always Below 1 Ω
E74-4 (CLTS) - E37-20 (CLTS) Always Below 1 Ω
E74-2 (CLTE) - E37-21 (CLTE) Always Below 1 Ω
E74-1 (CLTB) or E37-8 (CLTB) - Body ground Always 10 kΩ or higher
E74-4 (CLTS) or E37-20 (CLTS) - Body ground Always 10 kΩ or higher
E74-2 (CLTE) or E37-21 (CLTE) - Body ground Always 10 kΩ or higher



Result:
Proceed to
OK
NG



OK

5.INSPECT MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.INSPECT MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)
E364086C37
0.229,0.99 0.635,1.24 0.406,0.25 2.813,0.74 2.625,0.74 2.625,0.74 2.156,1.083 true 2.635,1.792 2.448,1.792 2.448,1.792 2.188,1.281 true 0.208,0.135 0.521,0.292 0.313,0.156 10 false *a 0.302,1.031 0.615,1.188 0.313,0.156 10 false E37 2.875,0.677 3.271,0.833 0.396,0.156 10 false CLTB 2.698,1.729 3.094,1.885 0.396,0.156 10 false CLTE
*a Component with harness connected
(Main Body ECU (Multiplex Network Body ECU))


a.

Connect the E37 main body ECU (multiplex network body ECU) connector.


b.

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

Standard Voltage:
Tester Connection Condition Specified Condition

Click Location & Routing(E37)Location & Routing

Click Connector(E37)Instrument Panel>Instrument Panel Wire / Radio Wiring Sub-Assy / Telephone Computer Wire>Multiplex Network Body ECU

E37-8 (CLTB) - E37-21 (CLTE) Ignition switch ON 11 to 14 V



Result:
Proceed to
OK
NG



OK

6.INSPECT AUTOMATIC LIGHT CONTROL SENSOR

NG

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

Click herePower Source / Network>POWER DISTRIBUTION>MAIN BODY ECU>REMOVAL