Note
Before replacing the main body ECU (multiplex network body ECU), refer to Service Bulletin.
The vehicle battery supplies power to the main body ECU (multiplex network body ECU) via the door control battery. Therefore, before proceeding with troubleshooting, perform an on-vehicle inspection and confirm that the main body ECU (multiplex network body ECU) power source circuit is normal.*
*: w/o Canister Pump Module with Door Ajar Warning Buzzer Function
If the headlight ECU sub-assembly LH has been replaced, it is necessary to synchronize the vehicle information and initialize the 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 LH (for Triple Beam Headlight) | |
| Headlight unit LH (for Single Beam Headlight) | ||
| Headlight unit assembly LH (for Triple Beam Headlight) | ||
| Headlight unit assembly LH (for Single Beam Headlight) | ||
| Headlight ECU sub-assembly LH | ||
| Right low beam headlight does not illuminate | Headlight unit RH (for Triple Beam Headlight) | |
| Headlight unit RH (for Single Beam Headlight) | ||
| Headlight unit assembly RH (for Triple Beam Headlight) | ||
| Headlight unit assembly RH (for Single Beam Headlight) | ||
| 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 | Headlight unit LH (for Triple Beam Headlight) | |
| High beam headlight circuit (for Single Beam Headlight) | ||
| Headlight unit assembly LH (for Triple Beam Headlight) | ||
| Headlight ECU sub-assembly LH | ||
| Right high beam headlight does not illuminate | Headlight unit RH (for Triple Beam Headlight) | |
| High beam headlight circuit (for Single Beam Headlight) | ||
| Headlight unit assembly RH (for Triple Beam Headlight) | ||
| 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 | |
| Headlight ECU sub-assembly LH | ||
| Right low beam headlight, high beam headlight, daytime running light and clearance light do not illuminate | Power source circuit | |
| Headlight ECU sub-assembly RH |
| Symptom | Suspected Area | Link |
|---|---|---|
| Left clearance light does not illuminate | Clearance Light/Daytime running light circuit | |
| Headlight ECU sub-assembly LH | ||
| Right clearance light does not illuminate | Clearance Light/Daytime running light circuit | |
| 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 | Clearance Light/Daytime running light circuit | |
| Headlight ECU sub-assembly LH | ||
| Right daytime running light does not illuminate | Clearance Light/Daytime running light circuit | |
| Headlight ECU sub-assembly RH | ||
| Both left and right daytime running lights do not illuminate | Check customize settings | |
| Electric parking brake system | ||
| Headlight dimmer switch circuit | ||
| Main body ECU (Multiplex network body ECU) |
| Symptom | Suspected Area | Link |
|---|---|---|
| Left or right taillight and rear side marker light (rear combination light assembly) do not illuminate | Rear combination light assembly | |
| Harness or connector | - | |
| Left or right taillight (rear light assembly) does not illuminate | Rear light assembly | |
| 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 (rear combination light assembly) does not illuminate | Rear combination light assembly | |
| Harness or connector | - | |
| Left or right stop light (rear light assembly) does not illuminate | Rear light assembly | |
| Harness or connector | - | |
| Center stop light does not illuminate | Center stop light assembly | |
| Harness or connector | - | |
| All of the stop lights do not illuminate | STOP fuse | - |
| Stop light switch assembly | ||
| Semiconductor pwr integration ECU | ||
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| Both left and right cornering lights do not illuminate* | Check operating conditions | |
| Headlight ECU sub-assembly LH | ||
| Main body ECU (Multiplex network body ECU) | ||
| Left cornering light does not illuminate | Check operating conditions | |
| Cornering light circuit | ||
| Headlight ECU sub-assembly LH | ||
| Right cornering light does not illuminate | Check operating conditions | |
| Cornering light circuit | ||
| Headlight ECU sub-assembly RH |
*: w/ Reverse linked cornering light function
| 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 | |
| Harness or connector | - | |
| Both left and right rear fog lights do not illuminate (taillights are normal) | Headlight dimmer switch circuit | |
| Rear fog light circuit | ||
| Main body ECU (Multiplex network body ECU) |
| Symptom | Suspected Area | Link |
|---|---|---|
| Left or right back-up light does not illuminate | back-up light bulb | |
| Rear light assembly | ||
| Harness or connector | - | |
| Both left and right back-up lights do not illuminate | BKUP LP fuse | - |
| Park/neutral position switch assembly (for U881E Automatic Transmission) | ||
| Park/neutral position switch assembly (for U881F Automatic Transmission) | ||
| Instrument panel junction block assembly | ||
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| Left or right front turn signal light does not operate (for Turn Signal Light Bulb Type) | Meter/gauge system | |
| Front turn signal light bulb | ||
| Headlight unit | ||
| Harness or connector | - | |
| Left or right front turn signal light does not operate (for Turn Signal Light LED Type) | Meter/gauge system | |
| No. 1 headlight clearance LED unit (for Single Beam Headlight) | ||
| Headlight LED unit assembly (for Triple Beam Headlight) | ||
| Headlight unit | ||
| Harness or connector | - | |
| Left or right rear turn signal light does not operate (for Turn Signal Light Bulb Type) | Meter/gauge system | |
| Rear turn signal light bulb | ||
| Rear combination light assembly | ||
| Harness or connector | - | |
| Left or right rear turn signal light does not operate (for Turn Signal Light LED Type) | Meter/gauge system | |
| Rear combination light assembly (on-vehicle inspection) | ||
| Rear light assembly (on-vehicle inspection) | ||
| Rear combination light assembly (inspection) | ||
| Rear light assembly (inspection) | ||
| Harness or connector | - | |
| Left or right side turn signal light does not operate | Side turn signal light assembly | |
| Outer rear view mirror assembly | ||
| Outer mirror control ECU assembly | ||
| Harness or connector | - | |
| Turn signal lights do not operate in one direction | Meter/gauge system | |
| Turn signal switch circuit | ||
| All turn signal lights do not operate | Turn signal switch circuit | |
| Combination meter assembly | ||
| All turn signal lights do not flash at the correct speed | Combination meter assembly |
| Symptom | Suspected Area | Link |
|---|---|---|
| Hazard warning signal lights do not operate | Hazard warning switch circuit | |
| Combination meter assembly | ||
| Hazard warning signal switch indicator does not illuminate | Radio receiver assembly (hazard warning signal switch) | |
| Combination meter assembly | ||
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| Automatic light control system does not operate | 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 | ||
| Door courtesy switch circuit | ||
| Main body ECU (Multiplex network body ECU) |
| Symptom | Suspected Area | Link |
|---|---|---|
| All of the outside handle foot lights do not illuminate | Power door lock control system | |
| Wireless door lock control system | ||
| Entry and start system (for Entry Function) | ||
| Door unlock detection switch circuit | ||
| Outside handle foot light circuit | ||
| Main body ECU (Multiplex network body ECU) | ||
| Left or right front door outside handle foot light does not illuminate | Front door outside handle assembly | |
| Harness or connector | - | |
| Left or right rear door outside handle foot light does not illuminate | Rear door outside handle assembly | |
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| Welcome light illumination control does not operate | Wireless door lock control system | |
| Headlight dimmer 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) |