Lexus NX: Problem Symptoms Table
PROBLEM SYMPTOMS TABLE
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.
- Inspect the fuses related to this system before inspecting the suspected areas below.
- Recognition code registration is necessary when replacing the main body ECU (multiplex network body ECU).
- If the main body ECU (multiplex network body ECU) is replaced, refer to Registration.
| Symptom | Suspected Area | Link |
|---|---|---|
| Illuminated entry system does not operate. | CAN communication system | |
| Smart access system with push-button start (for Entry Function) | | |
| DOME fuse | - | |
| Interior light circuit | | |
| Door unlock detection switch circuit | | |
| Door courtesy switch circuit | | |
| Back door courtesy switch circuit | | |
| IG signal circuit | | |
| ACC signal circuit | | |
| Interior light auto cut circuit | | |
| Harness or connector | - | |
| Main body ECU (Multiplex network body ECU) | |
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| Symptom | Suspected Area | Link |
|---|---|---|
| Map light assembly does not illuminate. | Map light assembly | |
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| Spot light assembly does not illuminate. | Map light assembly | |
| Spot light assembly | | |
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| No. 1 luggage compartment light assembly does not illuminate. | No. 1 luggage compartment light assembly LH | |
| No. 1 luggage compartment light assembly RH | | |
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| Glove box light assembly does not illuminate. | Glove box light bulb | |
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| Vanity light assembly does not illuminate. | Vanity light bulb | |
| Visor assembly | | |
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| Power switch illumination does not illuminate. | CAN communication system | |
| Headlight dimmer switch assembly | | |
| Power switch illumination circuit | | |
| Certification ECU (Smart key ECU assembly) | | |
| Main body ECU (Multiplex network body ECU) | |
| Symptom | Suspected Area | Link |
|---|---|---|
| Console box illumination light does not illuminate. | Console box illumination light assembly | |
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| Battery saving function (basic function) does not operate. | Door courtesy switch circuit | |
| Back door courtesy switch circuit | | |
| IG signal circuit | | |
| Harness or connector | - | |
| Main body ECU (Multiplex network body ECU) | | |
| Battery saving function (interior light auto cut function) does not operate. | Interior light auto cut circuit | |
| Main body ECU (Multiplex network body ECU) | |
| Symptom | Suspected Area | Link |
|---|---|---|
| One of the door outside handles does not illuminate. | Exterior illumination circuit | |
| Main body ECU (Multiplex network body ECU) | | |
| All of the door outside handles do not illuminate. | Main body ECU (Multiplex network body ECU) | |
| Harness or connector | - |
| Symptom | Suspected Area | Link |
|---|---|---|
| No. 1 interior illumination light assembly LH does not illuminate. | No. 1 interior illumination light assembly LH | |
| Harness or connector | - | |
| Instrument panel junction block assembly | | |
| No. 1 interior illumination light assembly RH does not illuminate. | No. 1 interior illumination light assembly RH | |
| Harness or connector | - | |
| Instrument panel junction block assembly | | |
| All footwell light does not illuminate. | Footwell light circuit | |
| Main body ECU (Multiplex network body ECU) | |
| Symptom | Suspected Area | Link |
|---|---|---|
| No instrument panel illumination lights come on (taillights operate normally). | PANEL fuse | - |
| Harness or connector | - |
READ NEXT:
Terminals Of Ecu
TERMINALS OF ECU CHECK INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY, MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) *1 Main Body ECU (Multiplex Network Body ECU) - - (a) Remove the main body ECU
Data List / Active Test
DATA LIST / ACTIVE TEST DATA LIST NOTICE: In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a pa
IG Signal Circuit
DESCRIPTION This circuit detects whether the power switch is on (IG) or off, and sends this information to the main body ECU (multiplex network body ECU). WIRING DIAGRAM CAUTION / NOTICE / HINT NOTI
SEE MORE:
Parts Location
PARTS LOCATION ILLUSTRATION *1 INNER REAR VIEW MIRROR ASSEMBLY *2 OUTER REAR VIEW MIRROR ASSEMBLY LH *3 OUTER REAR VIEW MIRROR ASSEMBLY RH *4 OUTER MIRROR LH *5 OUTER MIRROR RH *6 OUTER MIRROR CONTROL ECU ASSEMBLY LH *7 OUTER MIRROR CONTROL ECU ASSEMBLY RH *8
Diagnosis System
DIAGNOSIS SYSTEM DESCRIPTION When troubleshooting OBD II (On-Board Diagnostics) vehicles, the Techstream (complying with SAE J1978) must be connected to the DLC3 (Data Link Connector 3) of the vehicle. Various data in the vehicle's ECM (Engine Control Module) can be then read. OBD II regulations re
