LIGHTING SYSTEM PROBLEM SYMPTOMS TABLE

Note

If the main body ECU (multiplex network body ECU) is replaced, refer to the Service Bulletin.
As the door control battery is installed between the vehicle battery and main body ECU (multiplex network body ECU), first perform the inspections in On-Vehicle Inspection to confirm that there are no malfunctions in the power source circuit for the main body ECU (multiplex network body ECU) before performing this troubleshooting procedure.*

*: w/ Door Control Battery
When replacing the combination meter assembly, make sure to replace it with a new one.

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.
Inspect the fuses related to this system before inspecting the suspected areas below.

Headlight (for Triple Beam Headlight)
Symptom	Suspected Area	Link
Both left and right low beam headlights do not illuminate.	Headlight dimmer switch circuit	Click here
	Main body ECU (multiplex network body ECU) (for LHD)	Click here
	Main body ECU (multiplex network body ECU) (for RHD)	Click here
Low beam headlight on right side does not illuminate.	Headlight unit RH	Click here
	Headlight unit assembly RH	Click here
	Headlight ECU sub-assembly RH	Click here
Low beam headlight on left side does not illuminate.	Headlight unit LH	Click here
	Headlight unit assembly LH	Click here
	Headlight ECU sub-assembly LH	Click here
Both left and right high beam headlights do not illuminate.	Headlight dimmer switch circuit	Click here
	Main body ECU (multiplex network body ECU) (for LHD)	Click here
	Main body ECU (multiplex network body ECU) (for RHD)	Click here
High beam headlight on right side does not illuminate. (w/ Adaptive High Beam System)	Headlight unit RH	Click here
	Headlight unit assembly RH	Click here
	Headlight ECU sub-assembly RH	Click here
High beam headlight on left side does not illuminate. (w/ Adaptive High Beam System)	Headlight unit LH	Click here
	Headlight unit assembly LH	Click here
	Headlight ECU sub-assembly LH	Click here
High beam headlight on right side does not illuminate. (w/o Adaptive High Beam System)	High beam headlight circuit	Click here
High beam headlight on left side does not illuminate. (w/o Adaptive High Beam System)	High beam headlight circuit	Click here
High beam flash function does not operate (high beam headlights are normal).	Headlight dimmer switch circuit	Click here
	Main body ECU (multiplex network body ECU) (for LHD)	Click here
	Main body ECU (multiplex network body ECU) (for RHD)	Click here
Low beam and high beam headlight on right side does not illuminate.	Power source circuit	Click here
	Headlight ECU sub-assembly RH	Click here
Low beam and high beam headlight on left side does not illuminate.	Power source circuit	Click here
	Headlight ECU sub-assembly LH	Click here

Headlight (for Single Beam Headlight)
Symptom	Suspected Area	Link
Both left and right low beam headlights do not illuminate.	Headlight dimmer switch circuit	Click here
	Main body ECU (multiplex network body ECU) (for LHD)	Click here
	Main body ECU (multiplex network body ECU) (for RHD)	Click here
Low beam headlight on right side does not illuminate.	Headlight unit RH	Click here
	Headlight unit assembly RH	Click here
	Headlight ECU sub-assembly RH	Click here
Low beam headlight on left side does not illuminate.	Headlight unit LH	Click here
	Headlight unit assembly LH	Click here
	Headlight ECU sub-assembly LH	Click here
Both left and right high beam headlights do not illuminate.	Headlight dimmer switch circuit	Click here
	Main body ECU (multiplex network body ECU) (for LHD)	Click here
	Main body ECU (multiplex network body ECU) (for RHD)	Click here
High beam headlight on right side does not illuminate.	High beam headlight circuit	Click here
High beam headlight on left side does not illuminate.	High beam headlight circuit	Click here
High beam flash function does not operate (high beam headlights are normal).	Headlight dimmer switch circuit	Click here
	Main body ECU (multiplex network body ECU) (for LHD)	Click here
	Main body ECU (multiplex network body ECU) (for RHD)	Click here
Low beam and high beam headlight on right side does not illuminate.	Power source circuit	Click here
	Headlight ECU sub-assembly RH	Click here
Low beam and high beam headlight on left side does not illuminate.	Power source circuit	Click here
	Headlight ECU sub-assembly LH	Click here

Clearance Light
Symptom	Suspected Area	Link
Both left and right clearance lights do not illuminate.	Headlight dimmer switch circuit	Click here
	Main body ECU (multiplex network body ECU) (for LHD)	Click here
	Main body ECU (multiplex network body ECU) (for RHD)	Click here
Clearance light on right side does not illuminate.	Daytime running light relay circuit	Click here
Clearance light on right side does not illuminate.	Headlight ECU sub-assembly RH	Click here
Clearance light on left side does not illuminate.	Daytime running light relay circuit	Click here
Clearance light on left side does not illuminate.	Headlight ECU sub-assembly LH	Click here

Daytime Running Light
Symptom	Suspected Area	Link
Both left and right daytime running lights do not illuminate.	Headlight dimmer switch circuit	Click here
	Main body ECU (multiplex network body ECU) (for LHD)	Click here
	Main body ECU (multiplex network body ECU) (for RHD)	Click here
Daytime running light on right side does not illuminate.	Daytime running light relay circuit	Click here
Daytime running light on right side does not illuminate.	Headlight ECU sub-assembly RH	Click here
Daytime running light on left side does not illuminate.	Daytime running light relay circuit	Click here
Daytime running light on left side does not illuminate.	Headlight ECU sub-assembly LH	Click here
Clearance light and daytime running light on right side does not illuminate.	Power source circuit	Click here
	Daytime running light relay circuit	Click here
	Headlight ECU sub-assembly RH	Click here
Clearance light and daytime running light on left side does not illuminate.	Power source circuit	Click here
	Daytime running light relay circuit	Click here
	Headlight ECU sub-assembly LH	Click here

Front Fog Light (w/ Front Fog Light)
Symptom	Suspected Area	Link
Both left and right front fog lights do not illuminate (taillight is normal).	Headlight dimmer switch circuit	Click here
	Front fog light circuit	Click here
	Main body ECU (multiplex network body ECU) (for LHD)	Click here
	Main body ECU (multiplex network body ECU) (for RHD)	Click here
Front fog light on one side does not illuminate.	Front fog light circuit	Click here

Rear Fog Light (w/ Rear Fog Light)
Symptom	Suspected Area	Link
Rear fog light does not illuminate (taillight is normal).	Headlight dimmer switch circuit	Click here
	Rear fog light circuit	Click here
	Main body ECU (multiplex network body ECU) (for LHD)	Click here
	Main body ECU (multiplex network body ECU) (for RHD)	Click here

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

Taillight
Symptom	Suspected Area	Link
Taillight (rear combination light assembly) does not illuminate.	Rear combination light socket and wire sub-assembly	Click here
	Rear combination light assembly	Click here
	Harness or connector	-
	Instrument panel junction block assembly (for LHD)	Click here
	Instrument panel junction block assembly (for RHD)	Click here
Taillight (rear light assembly) does not illuminate.	Rear light assembly	Click here
	Harness or connector	-
	Instrument panel junction block assembly (for LHD)	Click here
	Instrument panel junction block assembly (for RHD)	Click here
All of the taillights do not illuminate	Headlight dimmer switch circuit	Click here
	Taillight relay circuit	Click here
	Main body ECU (multiplex network body ECU) (for LHD)	Click here
	Main body ECU (multiplex network body ECU) (for RHD)	Click here

Stop Light
Symptom	Suspected Area	Link
One side stop light (rear combination light assembly) does not illuminate.	Rear combination light socket and wire sub-assembly	Click here
	Rear combination light assembly	Click here
	Harness or connector	-
One side stop light (rear light assembly) does not illuminate.	Rear light assembly	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	-
All of the stop lights do not operate.	Harness or connector	-
	Stop light switch assembly	Click here
	Stop light control ECU assembly (for LHD)	Click here
	Stop light control ECU assembly (for RHD)	Click here

Back-up Light (w/o Rear Fog Light)
Symptom	Suspected Area	Link
All of the back-up lights do not operate.	Harness or connector	-
	Instrument panel junction block assembly (for LHD) [BKUP LP relay]	Click here
	Instrument panel junction block assembly (for RHD) [BKUP LP relay]	Click here
	ECM (for 3ZR-FAE)	Click here
	ECM (for 8AR-FTS)	Click here
Back-up light on one side does not illuminate.	Rear light assembly	Click here
Back-up light on one side does not illuminate.	Harness or connector	-

Back-up Light (w/ Rear Fog Light)
Symptom	Suspected Area	Link
Back-up light does not illuminate.	Harness or connector	-
	Rear light assembly	Click here
	Instrument panel junction block assembly (for LHD) [BKUP LP relay]	Click here
	Instrument panel junction block assembly (for RHD) [BKUP LP relay]	Click here
	ECM (for 3ZR-FAE)	Click here
	ECM (for 8AR-FTS)	Click here

Turn Signal Light
Symptom	Suspected Area	Link
No turn signal lights operate (hazard warning lights are normal).	Turn signal switch circuit	Click here
	Combination meter assembly	Click here
One of the turn signal lights does not operate.	Meter/gauge system	Click here

Cornering Light (w/ Front Fog Light)
Symptom	Suspected Area	Link
Both left and right cornering lights do not illuminate.	Headlight dimmer switch circuit	Click here
Both left and right cornering lights do not illuminate.	Combination meter assembly	Click here
Cornering light on right side does not illuminate.	Cornering light circuit	Click here
Cornering light on right side does not illuminate.	Headlight ECU sub-assembly RH	Click here
Cornering light on left side does not illuminate.	Cornering light circuit	Click here
Cornering light on left side does not illuminate.	Headlight ECU sub-assembly LH	Click here

Hazard Warning Light System
Symptom	Suspected Area	Link
Hazard warning lights do not operate (turn signal lights are normal).	Harness or connector	-
	Hazard warning switch circuit	Click here
	Combination meter assembly	Click here
Emergency brake signal (hazard warning light blink) does not operate (w/ Emergency Brake Signal)	CAN communication system	Click here
	Vehicle stability control system	Click here
	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
	Main body ECU (multiplex network body ECU) (for LHD)	Click here
	Main body ECU (multiplex network body ECU) (for RHD)	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
	Door courtesy switch circuit	Click here
	IG signal circuit	Click here
	Main body ECU (multiplex network body ECU) (for LHD)	Click here
	Main body ECU (multiplex network body ECU) (for RHD)	Click here

Follow Me Home System (w/ Follow Me Home System)
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) (for LHD)	Click here
	Main body ECU (multiplex network body ECU) (for RHD)	Click here

Welcome Light Illumination Control
Symptom	Suspected Area	Link
Welcome light illumination control does not operate.	Check customize parameters (Light up Clearance Lights at Door Unlock Function)	Click here
	Main body ECU (multiplex network body ECU) (for LHD)	Click here
	Main body ECU (multiplex network body ECU) (for RHD)	Click here