RM38T0EC _59 Vehicle Exterior _112294 LIGHTING (EXT) _0510962 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
B124400 Light Sensor Circuit Malfunction
Detection condition:

The ignition switch is to 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)



WIRING DIAGRAM

E549115E01
0.323,3.635 1.479,3.823 1.156,0.188 10 false h1*1, I290*2 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 4.677,0.958 4.99,1.156 0.313,0.198 10 false 8 4.625,2.042 4.938,2.24 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 I85 4.979,3.813 6.625,4.25 1.646,0.438 10 false Main Body ECU (Multiplex Network Body ECU) 5.469,1.333 6.094,1.583 0.625,0.25 10 false +B 0.313,4.427 2.458,4.74 2.146,0.313 10 false *1: for FTMS Made 1.979,4.427 4.125,4.74 2.146,0.313 10 false *2: for GTMC Made

CAUTION / NOTICE / HINT

NOTICE:

Before replacing the main body ECU (multiplex network body ECU), refer to Service Bulletin.*1

*1: w/ Smart Entry and Start System



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
Result:
Result Proceed to
B124400 is not output A
B124400 is output B




A

USE SIMULATION METHOD TO CHECK

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


B

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

Cover the automatic light control sensor with an opaque object.


b.

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.

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 Light control sensor illuminance 0 to 8191 lx or Sensor Fail 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 h1*1 or I290*2 automatic light control sensor connector.

*1: for FTMS Made

*2: for GTMC Made



b.

Disconnect the I85 main body ECU (multiplex network body ECU) connector.


c.

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

Standard Resistance:
for FTMS Made:
Tester Connection Condition Specified Condition
h1-1 (CLTB) - I85-8 (CLTB) Always Below 1 Ω
h1-4 (CLTS) - I85-20 (CLTS) Always Below 1 Ω
h1-2 (CLTE) - I85-21 (CLTE) Always Below 1 Ω
h1-1 (CLTB) - Body ground Always 10 kΩ or higher
I85-8 (CLTB) - Body ground Always 10 kΩ or higher
h1-4 (CLTS) - Body ground Always 10 kΩ or higher
I85-20 (CLTS) - Body ground Always 10 kΩ or higher
h1-2 (CLTE) - Body ground Always 10 kΩ or higher
I85-21 (CLTE) - Body ground Always 10 kΩ or higher

for GTMC Made:
Tester Connection Condition Specified Condition
I290-1 (CLTB) - I85-8 (CLTB) Always Below 1 Ω
I290-4 (CLTS) - I85-20 (CLTS) Always Below 1 Ω
I290-2 (CLTE) - I85-21 (CLTE) Always Below 1 Ω
I290-1 (CLTB) - Body ground Always 10 kΩ or higher
I85-8 (CLTB) - Body ground Always 10 kΩ or higher
I290-4 (CLTS) - Body ground Always 10 kΩ or higher
I85-20 (CLTS) - Body ground Always 10 kΩ or higher
I290-2 (CLTE) - Body ground Always 10 kΩ or higher
I85-21 (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)
a.

Connect the I85 main body ECU (multiplex network body ECU) connector.


E364086C57
0.229,0.99 0.635,1.24 0.406,0.25 2.125,1.115 2.635,0.792 true 2.198,1.271 2.469,1.688 true 0.208,0.135 0.521,0.292 0.313,0.156 10 false *a 0.333,1.021 0.646,1.177 0.313,0.156 10 false I85 2.698,0.708 3.094,0.865 0.396,0.156 10 false CLTB 2.479,1.729 2.875,1.885 0.396,0.156 10 false CLTE
*a Component with harness connected
(Main Body ECU (Multiplex Network Body ECU))


b.

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

Standard Voltage:
Tester Connection Switch Condition Specified Condition
I85-8 (CLTB) - I85-21 (CLTE) Ignition switch off Below 1 V
I85-8 (CLTB) - I85-21 (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