LIGHTING SYSTEM PROBLEM SYMPTOMS TABLE

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 and Taillight (for Halogen Headlight)
Symptom Suspected Area See page
One low beam headlight does not illuminate. Bulb -
Integration relay

Click here

Harness or connector -
Both left and right low beam headlights do not illuminate. Headlight dimmer switch circuit

Click here

Low beam headlight circuit

Click here

Main body ECU (Multiplex network body ECU)

Click here

One high beam headlight does not illuminate. H-LP LH HI fuse or H-LP RH HI fuse -
Bulb -
Integration relay

Click here

Harness or connector -
H-LP HI MAIN FUSE -
Both left and right high beam headlights do not illuminate. Headlight dimmer switch circuit

Click here

High beam headlight circuit

Click here

Main body ECU (Multiplex network body ECU)

Click here

"High Flash" (passing function) headlight does not illuminate (high beam headlights are normal). Headlight dimmer switch circuit

Click here

Main body ECU (Multiplex network body ECU)

Click here

One front parking light does not illuminate. Bulb -
Harness or connector -
One rear taillight does not illuminate. Rear combination light assembly

Click here

Harness or connector -
One license plate light does not illuminate. Bulb -
Harness or connector -
All of the lights (rear taillights, parking lights and license plate lights) do not illuminate. TAIL fuse -
Headlight dimmer switch circuit

Click here

Taillight relay circuit

Click here

Main body ECU (Multiplex network body ECU)

Click here

Headlight and Taillight (for LED Headlight)
Symptom Suspected Area See page
One low beam headlight does not illuminate. Check DTCs

Click here

Light control ECU

Click here

Integration relay

Click here

Headlight unit

Click here

Harness or connector -
Both left and right low beam headlights do not illuminate. Check DTCs

Click here

Headlight dimmer switch circuit

Click here

Low beam headlight circuit

Click here

Main body ECU (Multiplex network body ECU)

Click here

One high beam headlight does not illuminate. H-LP LH HI fuse or H-LP RH HI fuse -
Bulb -
Integration relay

Click here

Harness or connector -
Both left and right high beam headlights do not illuminate. H-LP HI MAIN FUSE -
Headlight dimmer switch circuit

Click here

High beam headlight circuit

Click here

Main body ECU (Multiplex network body ECU)

Click here

"High Flash" (passing function) headlight does not illuminate (high beam headlights are normal). Headlight dimmer switch circuit

Click here

Main body ECU (Multiplex network body ECU)

Click here

One front parking light does not illuminate. Headlight unit

Click here

Harness or connector -
One rear taillight does not illuminate. Rear combination light assembly

Click here

Harness or connector -
One license plate light does not illuminate. Bulb -
Harness or connector -
All of the lights (rear taillights, parking lights and license plate lights) do not illuminate. TAIL fuse -
Headlight dimmer switch circuit

Click here

Taillight relay circuit

Click here

Main body ECU (Multiplex network body ECU)

Click here

Stop Light
Symptom Suspected Area See page
One side stop light does not illuminate. Rear combination light assembly

Click here

Harness or connector -
High mounted stop light does not illuminate. Center stop light assembly

Click here

Center stop light wire harness

Click here

Harness or connector -
All of lights do not illuminate. STOP fuse -
Stop light switch assembly

Click here

Stop light control relay

Click here

Harness or connector -
Stop lights remain on Check electronically controlled brake system

Click here

Stop light switch assembly

Click here

Stop light control ECU assembly

Click here

Harness or connector -
Skid control ECU (for LHD)

Click here

Skid control ECU (for RHD)

Click here

Stop lights flash when the brake pedal is depressed Stop light control ECU assembly

Click here

Harness or connector -
Skid control ECU (for LHD)*1

Click here

Skid control ECU (for RHD)*1

Click here

Tech Tips

*1: Disconnect the skid control ECU connector, If the stop lights come on when the brake pedal is depressed, the skid control ECU may have a malfunction.

Front Fog Light
Symptom Suspected Area See page
One side front fog light does not illuminate. Bulb -
Harness or connector -
Both left and right front fog lights do not illuminate (taillights are normal). FR FOG fuse -
Headlight dimmer switch circuit

Click here

Front fog light circuit

Click here

Main body ECU (Multiplex network body ECU)

Click here

Rear Fog Light
Symptom Suspected Area See page
One side rear fog light does not illuminate. Bulb -
Harness or connector -
Both left and right rear fog lights do not illuminate (taillights are normal). RR FOG fuse -
Headlight dimmer switch circuit

Click here

Rear fog light circuit

Click here

Main body ECU (Multiplex network body ECU)

Click here

Back-up Light
Symptom Suspected Area See page
One back-up light does not illuminate. Bulb -
Harness or connector -
Both left and right back-up lights do not illuminate. Check hybrid control system

Click here

Back-up light circuit

Click here

Harness or connector -
Power management control ECU

Click here

Turn Signal Light
Symptom Suspected Area See page
Side turn signal light does not operate. Side turn signal light assembly

Click here

Harness or connector -
One turn signal light does not operate (except side turn signal lights). Bulb -
Harness or connector -
Headlight dimmer switch assembly (Turn signal light switch)

Click here

Turn signal lights do not operate in one direction. Turn signal flasher assembly

Click here

Harness or connector -
All turn signal lights do not operate. ECU-IG NO. 2 fuse -
HAZ fuse -
Headlight dimmer switch assembly (Turn signal light switch)

Click here

Turn signal flasher assembly

Click here

Harness or connector -
All turn signal lights do not flash at the correct speed. Bulb -
Turn signal flasher assembly

Click here

Harness or connector -
Hazard Warning Light
Symptom Suspected Area See page
Hazard warning lights do not operate. HAZ fuse -
ECU-IG NO. 2 fuse -
Hazard warning switch

Click here

Turn signal flasher assembly

Click here

Harness or connector -
Hazard warning lights flash when the hazard warning switch is not turned on. Check electronically controlled brake system

Click here

Hazard warning switch

Click here

Turn signal flasher assembly

Click here

Harness or connector -
Skid control ECU (for LHD)*2

Click here

Skid control ECU (for RHD)*2

Click here

Main body ECU (Multiplex network body ECU)

Click here

Tech Tips

*2: Disconnect the skid control ECU connector, If the hazard warning lights go off, the skid control ECU may have a malfunction.

Automatic Light Control System
Symptom Suspected Area See page
Automatic light control system does not operate. Check DTCs

Click here

Headlight dimmer switch circuit

Click here

IG signal circuit

Click here

Main body ECU (Multiplex network body ECU)

Click here

Light Auto Turn-off System
Symptom Suspected Area See page
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)

Click here

Daytime Running Light System
Symptom Suspected Area See page
Daytime running light system does not operate. Check CAN communication system

Click here

Headlight dimmer switch circuit

Click here

IG signal circuit

Click here

Daytime running light relay circuit

Click here

Main body ECU (Multiplex network body ECU)

Click here

Automatic Headlight Beam Level Control
Symptom Suspected Area See page
Headlight beam level control indicator light flashes. Check DTCs

Click here

Indicator light circuit

Click here

Headlight leveling ECU assembly

Click here

Headlight beam level control does not operate (Indicator light is off). Check the FAIL-SAFE function

Click here

Headlight beam level control actuator circuit

Click here

Headlight signal circuit

Click here

Headlight leveling ECU power source circuit

Click here

Combination meter assembly (No. 3 meter circuit plate)

Click here

Headlight leveling motor

Click here

Headlight leveling ECU assembly

Click here

Headlight beam level control system indicator light does not come on when turning the power switch on (IG). Indicator light circuit

Click here

Headlight leveling ECU power source circuit

Click here

Headlight leveling ECU assembly

Click here

Combination meter assembly (No. 3 meter circuit plate)

Click here

DTC information can not be detected. Diagnosis circuit

Click here

Headlight leveling ECU assembly

Click here

Initialization can not be performed. Check DTCs

Click here

LVL terminal circuit

Click here

Headlight leveling ECU assembly

Click here

Note


  • Initialize the headlight leveling ECU assembly after the vehicle height changes due to replacement of the suspension or after performing such operations as removal and reinstallation or replacement of the rear height control sensor sub-assembly.

  • When the headlight leveling ECU assembly is replaced, the initialization is also necessary.