LIGHTING (EXT) LIGHTING SYSTEM Low Beam Headlight Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) controls the low beam headlights.

WIRING DIAGRAM

0.698,0.854 1.604,1.167 0.906,0.313 10 false from Battery 2.052,1.021 2.802,1.25 0.75,0.229 10 false H-LP-MAIN 3.448,1.396 4.031,1.615 0.583,0.219 10 false H-LP 4.396,1.25 6.021,1.708 1.625,0.458 10 false Instrument Panel Junction Block Assembly 3.271,3.052 4.146,3.281 0.875,0.229 10 false H-LP LH-LO 3.271,5.563 4.146,5.792 0.875,0.229 10 false H-LP RH-LO 1.052,3.604 1.427,3.802 0.375,0.198 10 false A43 1.052,3.76 2.74,4 1.688,0.24 10 false Headlight Assembly LH 1.083,6.115 1.458,6.313 0.375,0.198 10 false A45 1.083,6.281 2.771,6.521 1.688,0.24 10 false Headlight Assembly RH 2.854,2.792 3.135,3 0.281,0.208 10 false LO 3.156,2.792 3.438,3 0.281,0.208 10 false 4 2.865,5.302 3.146,5.51 0.281,0.208 10 false LO 3.146,5.302 3.427,5.51 0.281,0.208 10 false 4 1.427,2.042 2.24,2.281 0.813,0.24 10 false Low (LED) 1.135,2.688 2.604,2.906 1.469,0.219 10 false Light Control ECU LH 1.115,5.229 2.583,5.448 1.469,0.219 10 false Light Control ECU RH 3.125,0.76 3.354,0.979 0.229,0.219 10 false 1 3.938,0.771 4.167,0.99 0.229,0.219 10 false 2 3.135,1.01 3.365,1.229 0.229,0.219 10 false 3 3.938,1 4.167,1.219 0.229,0.219 10 false 5 4.458,0.865 4.781,1.063 0.323,0.198 10 false 3A 4.469,0.667 4.792,0.865 0.323,0.198 10 false 34 5.896,0.75 6.219,0.948 0.323,0.198 10 false 15 6.167,0.854 6.75,1.073 0.583,0.219 10 false HRLY 5.427,5.438 5.771,5.656 0.344,0.219 10 false MB 5.427,5.604 7.083,6.021 1.656,0.417 10 false Main Body ECU (Multiplex Network Body ECU) 0.521,5.344 0.75,5.552 0.229,0.208 10 false E 0.531,2.813 0.76,3.021 0.229,0.208 10 false E 0.354,2.813 0.583,3.021 0.229,0.208 10 false 8 0.344,5.344 0.573,5.552 0.229,0.208 10 false 8 1.427,4.552 2.24,4.792 0.813,0.24 10 false Low (LED)

CAUTION / NOTICE / HINT

NOTICE:: Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.PERFORM ACTIVE TEST USING GTS

Connect the GTS to the DLC3.

Turn the ignition switch to ON.

Turn the GTS on.

Enter the following menus: Body Electrical / Main Body / Active Test.

Perform the Active Test according to the display on the GTS.

Body Electrical > Main Body > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Headlight Relay	H-LP relay	OFF or ON	-

Body Electrical > Main Body > Active Test

Tester Display
Headlight Relay

50004 123 14

OK:: Headlight relay operates. (Low beam headlights illuminate.)

Result:

Proceed to
OK
NG

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

Click hereVehicle Exterior>LIGHTING (EXT)>LIGHTING SYSTEM>PROBLEM SYMPTOMS TABLE

2.INSPECT H-LP RELAY

Remove the H-LP relay from the engine room relay block and junction block assembly.

Inspect the H-LP relay.

Click hereVehicle Exterior>LIGHTING (EXT)>RELAY>ON-VEHICLE INSPECTION

Result:

Proceed to
OK
NG

3.CHECK HARNESS AND CONNECTOR (POWER SOURCE - H-LP RELAY)

REPLACE H-LP RELAY

3.CHECK HARNESS AND CONNECTOR (POWER SOURCE - H-LP RELAY)

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
1 (H-LP relay terminal) - Body ground	Always	11 to 14 V
3 (H-LP relay terminal) - Body ground	Always	11 to 14 V

Result:

Proceed to
OK
NG

4.CHECK HARNESS AND CONNECTOR (H-LP RELAY - HEADLIGHT ASSEMBLY)

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.CHECK HARNESS AND CONNECTOR (H-LP RELAY - HEADLIGHT ASSEMBLY)

Disconnect the A43 headlight assembly LH connector.

Disconnect the A45 headlight assembly RH connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
5 (H-LP relay terminal) - A43-4 (LO)	Always	Below 1 Ω
5 (H-LP relay terminal) - A45-4 (LO)	Always	Below 1 Ω
5 (H-LP relay terminal) or A43-4 (LO) - Body ground	Always	10 kΩ or higher
5 (H-LP relay terminal) or A45-4 (LO) - Body ground	Always	10 kΩ or higher

Result:

Proceed to
OK
NG

5.CHECK HARNESS AND CONNECTOR (H-LP RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.CHECK HARNESS AND CONNECTOR (H-LP RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

Disconnect the 3A instrument panel junction block assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
2 (H-LP relay terminal) - 3A-34	Always	Below 1 Ω
2 (H-LP relay terminal) or 3A-34 - Body ground	Always	10 kΩ or higher

Result:

Proceed to
OK
NG

6.INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

1.167,0.333 1.479,0.521 0.313,0.188 4.698,0.354 5.01,0.542 0.313,0.188 4.531,1.469 4.74,1.052 false 1.25,0.344 1.563,0.542 0.313,0.198 10 false 3A 4.76,0.354 5.073,0.552 0.313,0.198 10 false MB 4.344,1.5 4.958,1.698 0.615,0.198 10 false HRLY 0.146,0.094 0.458,0.292 0.313,0.198 10 false *a

Component without harness connected
(Instrument Panel Junction Block Assembly)

Remove the instrument panel junction block assembly.

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

Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
3A-34 - MB-15 (HRLY)	Always	Below 1 Ω

Result:

Proceed to
OK
NG

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

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

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

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