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Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> Accessories & Equipment >> Exterior Lights >> Lighting System (W/O AFS) - Diagnostics - Introduction >> LIGHTING SYSTEM (w/o AFS) >> Problem Symptoms Table [10/2022 - 11/2023] >> Problem Symptoms Table [10/2022 - 11/2023]

Problem Symptoms Table [10/2022 - 11/2023]

NOTE:
  • Before replacing the main body ECU (multiplex network body ECU), refer to Registration.

    for HV Model: Refer to REGISTRATION [10/2021 - 11/2023]

    for Gasoline Model: Refer to REGISTRATION [10/2022 - 11/2023]

  • When replacing the combination meter assembly, always replace it with a new one. If a combination meter assembly which was installed to another vehicle is used, the information stored in it will not match the information from the vehicle and a DTC may be stored.

HINT: 

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 or right low beam headlight does not illuminate Refer to "LO-beam Headlight does not Illuminate" Refer to LO-beam Headlight does not Illuminate [12/2019 - 11/2023]
Both left and right low beam headlights do not illuminate Headlight dimmer switch circuit Refer to Headlight Dimmer Switch Circuit [12/2019 - 11/2023]
Main body ECU (Multiplex network body ECU) Refer to REMOVAL [10/2022 - 11/2023]
Left or right high beam headlight does not illuminate Headlight assembly Refer to INSPECTION [09/2020 - ]
Harness or connector -
Both left and right high beam headlights do not illuminate Headlight dimmer switch circuit Refer to Headlight Dimmer Switch Circuit [12/2019 - 11/2023]
High beam headlight circuit Refer to High Beam Headlight Circuit [09/2020 - 11/2023]
Main body ECU (Multiplex network body ECU) Refer to REMOVAL [10/2022 - 11/2023]
High Flash (passing function) does not operate (high beam headlights are normal) Headlight dimmer switch circuit Refer to Headlight Dimmer Switch Circuit [12/2019 - 11/2023]
Main body ECU (Multiplex network body ECU) Refer to REMOVAL [10/2022 - 11/2023]
PARKING LIGHT

Symptom Suspected Area Link
Left or right parking light does not illuminate*1 Headlight assembly Refer to INSPECTION [09/2020 - ]
Harness or connector -
Left or right parking light does not illuminate*2 Front turn signal light bulb Refer to REPLACEMENT [12/2019 - ]
Harness or connector -
Both left and right parking lights do not illuminate Taillight relay circuit Refer to Taillight Relay Circuit [12/2019 - 11/2023]
Harness or connector -
  1. *1: for LED Type
  2. *2: for Bulb Type
FRONT SIDE MARKER LIGHT

Symptom Suspected Area Link
Left or right front side marker light does not illuminate Front side marker light bulb Refer to REPLACEMENT [12/2019 - ]
Harness or connector -
Both left and right front side marker lights do not illuminate Taillight relay circuit Refer to Taillight Relay Circuit [12/2019 - 11/2023]
Harness or connector -
FRONT FOG LIGHT (W/ FRONT FOG LIGHT)

Symptom Suspected Area Link
Left or right front fog light does not illuminate Fog light assembly Refer to INSPECTION [09/2020 - ]
Harness or connector -
Both left and right front fog lights do not illuminate Headlight dimmer switch circuit Refer to Headlight Dimmer Switch Circuit [12/2019 - 11/2023]
Front fog light circuit Refer to Front Fog Light Circuit [09/2020 - 11/2023]
Main body ECU (Multiplex network body ECU) Refer to REMOVAL [10/2022 - 11/2023]
DAYTIME RUNNING LIGHT

Symptom Suspected Area Link
Left or right daytime running light does not illuminate Headlight assembly Refer to INSPECTION [09/2020 - ]
Harness or connector -
Both left and right daytime running lights do not illuminate Check customize settings* Refer to CUSTOMIZE PARAMETERS [10/2022 - 11/2023] 
Daytime running light circuit Refer to Daytime Running Light Circuit [09/2020 - 11/2023]
Headlight dimmer switch circuit Refer to Headlight Dimmer Switch Circuit [12/2019 - 11/2023]
Main body ECU (Multiplex network body ECU) Refer to REMOVAL [10/2022 - 11/2023]
  1. *: for vehicles with customize setting "DRL Function"
TAILLIGHT

Symptom Suspected Area Link
Left or right taillight (rear combination light assembly) does not illuminate Taillight LED Refer to INSPECTION [12/2019 - ]
Rear combination light cord Refer to REMOVAL [10/2022 - 11/2023]
Harness or connector -
Left or right taillight (rear light assembly) does not illuminate Rear light assembly Refer to INSPECTION [12/2019 - ]
Harness or connector -
All of the taillights, license plate lights and rear side marker lights do not illuminate Headlight dimmer switch circuit Refer to Headlight Dimmer Switch Circuit [12/2019 - 11/2023]
Taillight relay circuit Refer to Taillight Relay Circuit [12/2019 - 11/2023]
Main body ECU (Multiplex network body ECU) Refer to REMOVAL [10/2022 - 11/2023]
REAR SIDE MARKER LIGHT

Symptom Suspected Area Link
Left or right rear side marker light does not illuminate Rear combination light cord Refer to REMOVAL [10/2022 - 11/2023]
LICENSE PLATE LIGHT

Symptom Suspected Area Link
Left or right license plate light does not illuminate License plate light bulb Refer to REPLACEMENT [12/2019 - ]
Harness or connector -
License plate light assembly Refer to REMOVAL [12/2019 - ]
Both left and right license plate lights do not illuminate Taillight relay circuit Refer to Taillight Relay Circuit [12/2019 - 11/2023]
Harness or connector -
STOP LIGHT

Symptom Suspected Area Link
Left or right stop light does not illuminate Stop light LED Refer to INSPECTION [12/2019 - ]
Rear combination light cord Refer to REMOVAL [10/2022 - 11/2023]
Harness or connector -
All of the stop lights do not illuminate STOP fuse -
Stop light switch assembly Refer to ON-VEHICLE INSPECTION [12/2019 - ]
Harness or connector -
HIGH MOUNTED STOP LIGHT

Symptom Suspected Area Link
High mounted stop light does not illuminate Center stop light assembly Refer to INSPECTION [12/2019 - ]
Harness or connector -
BACK-UP LIGHT

Symptom Suspected Area Link
Left or right back-up light does not illuminate Back-up light bulb Refer to REPLACEMENT [12/2019 - ]
Harness or connector -
Both left and right back-up lights do not illuminate*1 Back-up light circuit Refer to Back-up Light Circuit [12/2019 - 11/2023]
Both left and right back-up lights do not illuminate*2 BKUP LP fuse -
ECU-ACC fuse -
Park/neutral position switch assembly Refer to INSPECTION [10/2022 - ]
Instrument panel junction block assembly Refer to REMOVAL [10/2022 - 11/2023]
Harness or connector -
  1. *1: for HV Model
  2. *2: for Gasoline Model
TURN SIGNAL LIGHT

Symptom Suspected Area Link
Left or right front turn signal light does not operate Front turn signal light bulb Refer to REPLACEMENT [12/2019 - ]
Harness or connector -
Left or right rear turn signal light does not operate Rear turn signal light bulb Refer to REPLACEMENT [12/2019 - ]
Rear combination light cord Refer to REMOVAL [10/2022 - 11/2023]
Harness or connector -
Left or right side turn signal light does not operate Side turn signal light assembly Refer to INSPECTION [12/2019 - ]
Outer rear view mirror assembly Refer to REMOVAL [12/2019 - 11/2023]
Outer mirror control ECU assembly*1 Refer to REMOVAL [12/2019 - ]
Harness or connector -
Turn signal lights do not operate in one direction Turn signal switch circuit Refer to Turn Signal Switch Circuit [12/2019 - ]
Meter/gauge system*2 Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2022 - ]
Meter/gauge system*3 Refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ]
All turn signal lights do not operate Turn signal switch circuit Refer to Turn Signal Switch Circuit [12/2019 - ]
Combination meter assembly Refer to REMOVAL [12/2019 - ]
All turn signal lights do not flash at the correct speed Combination meter assembly Refer to REMOVAL [12/2019 - ]
  1. *1: w/ Memory
  2. *2: for 12.3 Inch Display
  3. *3: except 12.3 Inch Display
HAZARD WARNING SIGNAL LIGHT

Symptom Suspected Area Link
Hazard warning signal lights do not operate Hazard warning switch circuit Refer to Hazard Warning Switch Circuit [10/2022 - ]
Combination meter assembly Refer to REMOVAL [12/2019 - ]
DOOR MIRROR FOOT LIGHT (W/ DOOR MIRROR FOOT LIGHT)

Symptom Suspected Area Link
Left or right door mirror foot light does not illuminate Door mirror foot light circuit Refer to Door Mirror Foot Light Circuit [12/2019 - 11/2023]
Outer mirror control ECU assembly Refer to REMOVAL [12/2019 - ]
Both left and right door mirror foot lights do not illuminate Check customize settings Refer to CUSTOMIZE PARAMETERS [10/2022 - 11/2023] 
Power door lock control system Refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - 11/2023]
Wireless door lock control system Refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - 11/2023]
Smart key system (for entry function) Refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - 11/2023]
Door unlock detection switch circuit Refer to Door Unlock Detection Switch Circuit [12/2019 - 11/2023]
Main body ECU (Multiplex network body ECU) Refer to REMOVAL [10/2022 - 11/2023]
AUTOMATIC LIGHT CONTROL SYSTEM

Symptom Suspected Area Link
Automatic light control system does not operate Headlight dimmer switch circuit Refer to Headlight Dimmer Switch Circuit [12/2019 - 11/2023]
Main body ECU (Multiplex network body ECU) Refer to REMOVAL [10/2022 - 11/2023]
LIGHT AUTO TURN-OFF SYSTEM

Symptom Suspected Area Link
Light auto turn-off system does not operate Headlight dimmer switch circuit Refer to Headlight Dimmer Switch Circuit [12/2019 - 11/2023]
IG signal circuit Refer to IG Signal Circuit [12/2019 - 11/2023]
Front door courtesy switch circuit Refer to Front Door Courtesy Switch Circuit [12/2019 - 11/2023]
Rear door courtesy switch circuit Refer to Rear Door Courtesy Switch Circuit [12/2019 - 11/2023]
Back door courtesy switch circuit Refer to Back Door Courtesy Switch Circuit [12/2019 - 11/2023]
Main body ECU (Multiplex network body ECU) Refer to REMOVAL [10/2022 - 11/2023]
REMOTE OPERATION FUNCTION (W/ TELEMATICS SYSTEM)

Symptom Suspected Area Link
Lights do not operate using remote operation function (Lighting system is normal) Telematics system Refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ]
WIPER-LINKED LOW BEAM HEADLIGHT CONTROL SYSTEM

Symptom Suspected Area Link
Wiper-linked low beam headlight control system does not operate Check customize settings Refer to CUSTOMIZE PARAMETERS [10/2022 - 11/2023] 
Main body ECU (Multiplex network body ECU) Refer to REMOVAL [10/2022 - 11/2023]
WELCOME LIGHT ILLUMINATION CONTROL

Symptom Suspected Area Link
Welcome light illumination control does not operate Check customize settings Refer to CUSTOMIZE PARAMETERS [10/2022 - 11/2023] 
Main body ECU (Multiplex network body ECU) Refer to REMOVAL [10/2022 - 11/2023]
AUTOMATIC HIGH BEAM SYSTEM

Symptom Suspected Area Link
Automatic high beam system does not operate or automatic high beam indicator does not illuminate (low beam headlights and high beam headlights are normal) Front radar sensor system Refer to Automatic High Beam System does not Operate or Operation Indicator does not Illuminate [10/2022 - 11/2023]
Check Data List (Front Recognition Camera High Temperature 2)
Check automatic high beam indicator light
Check Data List (Auto H Beam STS0)
Perform Active Test (Multi Display All (White))
Auto high beam switch
Harness or connector
Combination meter assembly
Forward recognition camera
Main body ECU (Multiplex network body ECU)
Auto high beam switch indicator does not come ON Refer to "Automatic High Beam Switch Indicator does not Come ON" Refer to Automatic High Beam Switch Indicator does not Come ON [12/2019 - 11/2023]
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