Note
If the main body ECU (multiplex network body ECU) is replaced, refer to Service Bulletin.*
*: w/ Smart Entry and Start System
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 |
|---|---|---|
| One low beam headlight does not illuminate | H-LP LO LH fuse or H-LP LO RH fuse | - |
| Bulb | ||
| Semiconductor pwr integration ECU | ||
| Harness or connector | - | |
| Both left and right low beam headlights do not illuminate | Headlight dimmer switch circuit | |
| Low beam headlight circuit | ||
| Main body ECU (Multiplex network body ECU) | ||
| One high beam headlight does not illuminate | Bulb | |
| Semiconductor pwr integration ECU | ||
| Harness or connector | - | |
| 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) |
| Symptom | Suspected Area | Link |
|---|---|---|
| One low beam headlight does not illuminate | H-LP LO LH fuse or H-LP LO RH fuse | - |
| Light control LED ECU | ||
| Headlight unit | ||
| Semiconductor pwr integration ECU | ||
| Harness or connector | - | |
| Both left and right low beam headlights do not illuminate | Headlight dimmer switch circuit | |
| Low beam headlight circuit | ||
| Main body ECU (Multiplex network body ECU) | ||
| One high beam headlight does not illuminate | Bulb | |
| Semiconductor pwr integration ECU | ||
| Harness or connector | - | |
| Both left and right high beam headlights do not illuminate | Headlight dimmer switch circuit | |
| High beam headlight 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) |
| Symptom | Suspected Area | Link |
|---|---|---|
| One clearance light does not illuminate | Bulb (for Halogen Headlight) | |
| Bulb (for LED Headlight) | ||
| Harness or connector | - | |
| Both left and right clearance lights do not illuminate | Harness or connector | - |
| Instrument panel junction block assembly |
| Symptom | Suspected Area | Link |
|---|---|---|
| One side taillight (rear combination light assembly) do not illuminate | Bulb | |
| Rear combination light assembly | ||
| Harness or connector | - | |
| One taillight (rear light assembly) does not illuminate | Bulb | |
| Rear light assembly | ||
| Harness or connector | - | |
| All of the lights (taillights, clearance lights, and license plate lights) do not illuminate | Headlight dimmer switch circuit | |
| Taillight relay circuit | ||
| Main body ECU (Multiplex network body ECU) |
| Symptom | Suspected Area | Link |
|---|---|---|
| One license plate light does not illuminate | Bulb | |
| Harness or connector | - | |
| Both left and right license plate lights do not illuminate | Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| One side stop light does not illuminate | Bulb | |
| Rear combination light assembly | ||
| Harness or connector | - | |
| Center stop light does not illuminate | Center stop light assembly | |
| Radio setting condenser | ||
| Harness or connector | - | |
| All of the stop lights do not illuminate | STOP fuse | - |
| STOP LP relay (w/ Dynamic Radar Cruise Control System) | ||
| Stop light switch assembly | ||
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| One front fog light does not illuminate | Bulb | |
| 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 |
|---|---|---|
| One rear fog light does not illuminate | Bulb | |
| 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 |
|---|---|---|
| One back-up light does not illuminate | Bulb | |
| Harness or connector | - | |
| Both left and right back-up lights do not illuminate | BKUP LP fuse | - |
| Park/Neutral position switch assembly (for U660E Automatic Transmission) | ||
| Park/Neutral position switch assembly (for U660F Automatic Transmission) | ||
| Park/Neutral position switch assembly (for U760E Automatic Transmission) | ||
| Instrument panel junction block assembly | ||
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| One turn signal light does not operate (except side turn signal lights) | Bulb (for Front Side) (for Halogen Headlight) | |
| Bulb (for Front Side) (for LED Headlight) | ||
| Bulb (for Rear Side) | ||
| Harness or connector | - | |
| One 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 | ||
| 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 |
| 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 | ||
| Rear door courtesy switch circuit | ||
| Main body ECU (Multiplex network body ECU) |
| Symptom | Suspected Area | Link |
|---|---|---|
| Daytime running light system does not operate (both left and right daytime running lights do not illuminate) | CAN communication system | |
| Headlight dimmer switch circuit | ||
| IG signal circuit | ||
| Parking brake switch circuit | ||
| Daytime running light relay circuit | ||
| Main body ECU (Multiplex network body ECU) | ||
| One side daytime running light does not illuminate | Daytime running light assembly | |
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| Both left and right door mirror foot lights do not illuminate | CAN communication system | |
| Power door lock control system | ||
| Wireless door lock control system | ||
| Smart entry and start system (for entry function) | ||
| Door mirror foot light circuit | ||
| Door unlock detection switch circuit | ||
| Main body ECU (Multiplex network body ECU) | ||
| One door mirror foot light does not illuminate | Door mirror foot light circuit | |
| Outer mirror control ECU assembly |
| 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) |