LIGHTING SYSTEM PROBLEM SYMPTOMS TABLE

Note

Before replacing the main body ECU (multiplex network body ECU), refer to Service Bulletin.
If the No. 1 headlight ECU sub-assembly LH has been replaced, it is necessary to synchronize the vehicle information and initialize the No. 1 headlight ECU sub-assembly LH.

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Tech Tips

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" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.

Headlight
Symptom	Suspected Area	Link
Left low beam headlight does not illuminate	Headlight unit LH (for Bulb Type Turn Signal Light)	Click here
	Headlight unit LH (for LED Type Turn Signal Light)	Click here
	No. 1 headlight ECU sub-assembly LH	Click here
Right low beam headlight does not illuminate	Headlight unit RH (for Bulb Type Turn Signal Light)	Click here
	Headlight unit RH (for LED Type Turn Signal Light)	Click here
	No. 1 headlight ECU sub-assembly RH	Click here
Both left and right low beam headlights do not illuminate	Headlight dimmer switch circuit	Click here
Both left and right low beam headlights do not illuminate	Main body ECU (Multiplex network body ECU)	Click here
Left high beam headlight does not illuminate	High beam headlight circuit	Click here
Left high beam headlight does not illuminate	No. 1 headlight ECU sub-assembly LH	Click here
Right high beam headlight does not illuminate	High beam headlight circuit	Click here
Right high beam headlight does not illuminate	No. 1 headlight ECU sub-assembly RH	Click here
Both left and right high beam headlights do not illuminate	Headlight dimmer switch circuit	Click here
Both left and right high beam headlights do not illuminate	Main body ECU (Multiplex network body ECU)	Click here
High Flash (passing function) does not operate (high beam headlights are normal)	Headlight dimmer switch circuit	Click here
	Main body ECU (Multiplex network body ECU)	Click here
Left low beam headlight and high beam headlight do not illuminate	Power source circuit	Click here
	No. 1 headlight ECU sub-assembly LH	Click here
Right low beam headlight and high beam headlight do not illuminate	Power source circuit	Click here
	No. 1 headlight ECU sub-assembly RH	Click here

Clearance Light, Daytime Running Light
Symptom	Suspected Area	Link
Left clearance light does not illuminate	Clearance light/daytime running light circuit	Click here
Left clearance light does not illuminate	No. 1 headlight ECU sub-assembly LH	Click here
Right clearance light does not illuminate	Clearance light/daytime running light circuit	Click here
Right clearance light does not illuminate	No. 1 headlight ECU sub-assembly RH	Click here
Both left and right clearance lights do not illuminate	Headlight dimmer switch circuit	Click here
Both left and right clearance lights do not illuminate	Main body ECU (Multiplex network body ECU)	Click here
Left daytime running light does not illuminate	Clearance light/daytime running light circuit	Click here
Left daytime running light does not illuminate	No. 1 headlight ECU sub-assembly LH	Click here
Right daytime running light does not illuminate	Clearance light/daytime running light circuit	Click here
Right daytime running light does not illuminate	No. 1 headlight ECU sub-assembly RH	Click here
Both left and right daytime running lights do not illuminate	CAN communication system	Click here
	Headlight dimmer switch circuit	Click here
	Parking brake switch circuit	Click here
	Clearance light/daytime running light circuit	Click here
	Harness or connector	-
	Main body ECU (Multiplex network body ECU)	Click here
Left clearance light and daytime running light do not illuminate	Clearance light/daytime running light circuit	Click here
	No. 1 headlight ECU sub-assembly LH	Click here
Right clearance light and daytime running light do not illuminate	Clearance light/daytime running light circuit	Click here
	No. 1 headlight ECU sub-assembly RH	Click here

Taillight
Symptom	Suspected Area	Link
Left or right taillight (rear combination light assembly) do not illuminate	Rear combination light lens and body	Click here
	Rear combination light socket and wire sub-assembly	Click here
	Harness or connector	-
Left or right taillight (rear light assembly) does not illuminate	Rear light assembly	Click here
	Rear light socket and wire	Click here
	Harness or connector	-
All of the taillights, license plate lights, and clearance lights do not illuminate	Headlight dimmer switch circuit	Click here
	Taillight relay circuit	Click here
	Main body ECU (Multiplex network body ECU)	Click here

License Plate Light
Symptom	Suspected Area	Link
License plate light does not illuminate	License plate light assembly	Click here
License plate light does not illuminate	Harness or connector	-

Stop Light
Symptom	Suspected Area	Link
All of the stop lights do not illuminate	STOP fuse	-
	Stop light switch assembly	Click here
	Semiconductor pwr integration ECU	Click here
	Harness or connector	-
Center stop light does not illuminate	Center stop light assembly	Click here
Center stop light does not illuminate	Harness or connector	-
Left or right stop light does not illuminate	Rear combination light lens and body	Click here
	Rear combination light socket and wire sub-assembly	Click here
	Harness or connector	-

Rear Fog Light (w/ Rear Fog Light)
Symptom	Suspected Area	Link
Rear fog light does not illuminate	Rear light assembly	Click here
	Rear light socket and wire	Click here
	Headlight dimmer switch circuit	Click here
	Rear fog light circuit	Click here
	Main body ECU (Multiplex network body ECU)	Click here

Back-up Light (w/ Rear Fog Light)
Symptom	Suspected Area	Link
Back-up light does not illuminate	BKUP LP fuse	-
	Back-up light circuit	Click here
	Rear light assembly	Click here
	Rear light socket and wire	Click here

Back-up Light (w/o Rear Fog Light)
Symptom	Suspected Area	Link
Both left and right back-up lights do not illuminate	BKUP LP fuse	-
Both left and right back-up lights do not illuminate	Back-up light circuit	Click here
One back-up light does not illuminate	Rear light assembly	Click here
	Rear light socket and wire	Click here
	Harness or connector	-

Turn Signal Light
Symptom	Suspected Area	Link
Turn signal lights do not operate in one direction	Turn signal switch circuit	Click here
	Windshield wiper switch assembly	Click here
	Meter/gauge system	Click here
All turn signal lights do not operate	Turn signal switch circuit	Click here
	Windshield wiper switch assembly	Click here
	Combination meter assembly	Click here
Left or right turn signal light does not operate	Front turn signal light bulb (for Bulb Type Turn Signal Light)	Click here
	Headlight LED unit assembly (for LED Type Turn Signal Light)	Click here
	Headlight unit (for Bulb Type Turn Signal Light)	Click here
	Headlight unit (for LED Type Turn Signal Light)	Click here
	Rear turn signal light bulb (for Bulb Type Turn Signal Light)	Click here
	Rear combination light lens and body (for LED Type Turn Signal Light)	Click here
	Rear combination light socket and wire sub-assembly (for LED Type Turn Signal Light)	Click here
	Harness or connector	-
One side turn signal light does not operate	Side turn signal light assembly	Click here
	Outer rear view mirror assembly	Click here
	Outer mirror control ECU assembly (for Power Mirror Control System (w/ Memory))	Click here
	Harness or connector	-
All turn signal lights do not flash at the correct speed	Combination meter assembly	Click here

Hazard Warning Signal Light
Symptom	Suspected Area	Link
Hazard warning signal lights do not operate	Hazard warning switch circuit	Click here
Hazard warning signal lights do not operate	Combination meter assembly	Click here

Automatic Light Control System
Symptom	Suspected Area	Link
Automatic light control system does not operate	Headlight dimmer switch circuit	Click here
Automatic light control system does not operate	Main body ECU (Multiplex network body ECU)	Click here

Light Auto Turn-off System
Symptom	Suspected Area	Link
Light auto turn-off system does not operate	Headlight dimmer switch circuit	Click here
	Front door courtesy switch circuit (except European Models)	Click here
	IG signal circuit	Click here
	Main body ECU (Multiplex network body ECU)	Click here

Door Mirror Foot Light
Symptom	Suspected Area	Link
Both left and right door mirror foot lights do not illuminate	CAN communication system	Click here
	Power door lock control system	Click here
	Wireless door lock control system	Click here
	Entry and start system (for Entry Function)	Click here
	Door mirror foot light circuit	Click here
	Door unlock detection switch circuit	Click here
	Main body ECU (Multiplex network body ECU)	Click here
One door mirror foot light does not illuminate (for Power Mirror Control System (w/ Memory)	Door mirror foot light circuit	Click here
	Outer mirror control ECU assembly	Click here
One door mirror foot light does not illuminate (for Power Mirror Control System (w/o Memory)	Door mirror foot light circuit	Click here
	Main body ECU (Multiplex network body ECU)	Click here

Welcome Light Illumination Control
Symptom	Suspected Area	Link
Welcome light illumination control does not operate	Wireless door lock control system	Click here
	Headlight dimmer switch circuit	Click here
	Main body ECU (Multiplex network body ECU)	Click here

Follow Me Home System (for European Models)
Symptom	Suspected Area	Link
Follow me home system does not operate	IG signal circuit	Click here
	Headlight dimmer switch circuit	Click here
	Main body ECU (Multiplex network body ECU)	Click here