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.
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.
| Symptom | Suspected Area | Link |
|---|---|---|
| Left low beam headlight does not illuminate | Headlight unit assembly LH | |
| Headlight unit LH | ||
| No. 1 Headlight ECU sub-assembly LH | ||
| Right low beam headlight does not illuminate | Headlight unit assembly RH | |
| Headlight unit RH | ||
| No. 1 Headlight ECU sub-assembly RH | ||
| Both left and right low beam headlights do not illuminate | Headlight dimmer switch circuit | |
| Main body ECU (Multiplex network body ECU) | ||
| Left high beam headlight does not illuminate | High beam headlight circuit | |
| Headlight unit assembly LH | ||
| No. 1 Headlight ECU sub-assembly LH | ||
| Right high beam headlight does not illuminate | High beam headlight circuit | |
| Headlight unit assembly RH | ||
| No. 1 Headlight ECU sub-assembly RH | ||
| Both left and right high beam headlights do not illuminate | Headlight dimmer switch circuit | |
| Main body ECU (Multiplex network body ECU) | ||
| High Flash (passing function) does not operate (high beam headlights are normal) | Headlight dimmer switch circuit | |
| Main body ECU (Multiplex network body ECU) | ||
| Left low beam headlight, high beam headlight, daytime running light and clearance light do not illuminate | Power source circuit | |
| No. 1 Headlight ECU sub-assembly LH | ||
| Right low beam headlight, high beam headlight, daytime running light and clearance light do not illuminate | Power source circuit | |
| No. 1 Headlight ECU sub-assembly RH |
| Symptom | Suspected Area | Link |
|---|---|---|
| Left clearance light does not illuminate | Clearance Light circuit | |
| No. 1 Headlight ECU sub-assembly LH | ||
| Right clearance light does not illuminate | Clearance Light circuit | |
| No. 1 Headlight ECU sub-assembly RH | ||
| Both left and right clearance lights do not illuminate | Headlight dimmer switch circuit | |
| Main body ECU (Multiplex network body ECU) |
| Symptom | Suspected Area | Link |
|---|---|---|
| Left daytime running light does not illuminate | Daytime running light circuit | |
| Fog light assembly LH | ||
| No. 1 Headlight ECU sub-assembly LH | ||
| Right daytime running light does not illuminate | Daytime running light circuit | |
| Fog light assembly RH | ||
| No. 1 Headlight ECU sub-assembly RH | ||
| Both left and right daytime running lights do not illuminate | Headlight dimmer switch circuit | |
| Main body ECU (Multiplex network body ECU) |
| Symptom | Suspected Area | Link |
|---|---|---|
| Left or right taillight (rear combination light assembly) do not illuminate | Rear combination light assembly | |
| Rear combination light socket and wire sub-assembly | ||
| Rear combination light lens and body | ||
| Harness or connector | - | |
| Left or right taillight (rear light assembly) does not illuminate | Rear light assembly | |
| Rear light lens and body | ||
| Harness or connector | - | |
| All of the taillights, license plate lights and rear side marker lights do not illuminate | Headlight dimmer switch circuit | |
| Taillight relay circuit | ||
| Main body ECU (Multiplex network body ECU) |
| Symptom | Suspected Area | Link |
|---|---|---|
| Left or right license plate light does not illuminate | License plate light assembly | |
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| Left or right stop light does not illuminate | Rear light assembly | |
| Rear combination light LED | ||
| Harness or connector | - | |
| Center stop light does not illuminate | Center stop light SET | |
| Harness or connector | - | |
| All of the stop lights do not illuminate | STOP fuse | - |
| Stop light switch assembly | ||
| Instrument panel junction block assembly | ||
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| Left or right front fog light does not illuminate | Fog light assembly | |
| Harness or connector | - | |
| Both left and right front fog lights do not illuminate (taillights are normal) | Headlight dimmer switch circuit | |
| Front fog light circuit | ||
| Main body ECU (Multiplex network body ECU) |
| Symptom | Suspected Area | Link |
|---|---|---|
| Left or right rear fog light does not illuminate | Rear light assembly | |
| Rear fog light LED | ||
| Rear light lens and body | ||
| Harness or connector | - | |
| Both left and right rear fog lights do not illuminate (taillights are normal) | Headlight dimmer switch circuit | |
| Main body ECU (Multiplex network body ECU) |
| Symptom | Suspected Area | Link |
|---|---|---|
| Left or right back-up light does not illuminate | Rear combination light assembly | |
| Back-up light circuit | ||
| Back-up light bulb | ||
| Rear combination light socket and wire sub-assembly | ||
| Harness or connector | - | |
| Both left and right back-up lights do not illuminate | Back-up light circuit | |
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| Left or right front turn signal light does not operate | Front turn signal light bulb | |
| Harness or connector | - | |
| Left or right rear turn signal light does not operate | Rear turn signal light bulb | |
| Rear combination light assembly | ||
| Rear combination light socket and wire sub-assembly | ||
| Harness or connector | - | |
| Left or right side turn signal light does not operate | Side turn signal light assembly | |
| Outer rear view mirror assembly | ||
| Harness or connector | - | |
| Turn signal lights do not operate in one direction | Turn signal switch circuit | |
| Meter/gauge system | ||
| All turn signal lights do not operate | Turn signal switch circuit | |
| Combination meter assembly (Meter circuit plate) | ||
| All turn signal lights do not flash at the correct speed | Combination meter assembly (Meter circuit plate) |
| Symptom | Suspected Area | Link |
|---|---|---|
| Hazard warning signal lights do not operate | Hazard warning switch circuit | |
| Combination meter assembly (Meter circuit plate) | ||
| Hazard warning signal switch indicator does not illuminate | Hazard warning signal switch assembly | |
| Combination meter assembly (Meter circuit plate) | ||
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| Automatic light control system does not operate | Check DTCs | |
| Headlight dimmer switch circuit | ||
| Main body ECU (Multiplex network body ECU) |
| Symptom | Suspected Area | Link |
|---|---|---|
| Light auto turn-off system does not operate | Headlight dimmer switch circuit | |
| IG signal circuit | ||
| Front door courtesy switch circuit | ||
| Main body ECU (Multiplex network body ECU) |
| Symptom | Suspected Area | Link |
|---|---|---|
| Follow me home system does not operate | IG signal circuit | |
| Headlight dimmer switch circuit | ||
| Main body ECU (Multiplex network body ECU) |