Problem Symptoms Table [11/2021 - 03/2023]
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2025 Lexus NX 350, 2025 Lexus NX 250, 2024 Lexus NX 350, 2024 Lexus NX 250, and 2023 Lexus NX 350. However, it is still accessible from the selected car via links, so may be relevant.
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 and relays related to the system before inspecting the suspected areas below.
- If the problem occurs in certain locations or times of day, the possibility of wave interference is high.
- If a malfunction occurred after optional components were installed by the dealer, check if there is wave interference from the components.
SMART ACCESS SYSTEM WITH PUSH-BUTTON START (FOR START FUNCTION)
| Symptom | Suspected Area | Link |
|---|---|---|
| Power source mode does not change to ON or ACC | Smart access system with push-button start (for Entry Function) | Refer to Power Source Mode does not Change to ON (IG and ACC) [11/2021 - ] |
| Affected by wave interference | ||
| Transmitter battery | ||
| Electrical key transmitter sub-assembly | ||
| No. 1 indoor electrical key antenna assembly (front floor) | ||
| No. 2 indoor electrical key antenna assembly (rear floor) | ||
| No. 3 indoor electrical key antenna assembly (inside luggage compartment) | ||
| Engine switch | ||
| Wire harness or connector | ||
| Power distribution box assembly | ||
| Certification ECU (Smart key ECU assembly) | ||
| Power source mode does not change to ON | Wire harness or connector | Refer to Power Source Mode does not Change to ON (IG) [11/2021 - ] |
| Relay | ||
| Power distribution box assembly | ||
| Certification ECU (Smart key ECU assembly) | ||
| Power source mode does not change to ACC | Wire harness or connector | Refer to Power Source Mode does not Change to ON (ACC) [11/2021 - ] |
| Relay | ||
| Power distribution box assembly | ||
| Certification ECU (Smart key ECU assembly) | ||
| Only +BA power source mode does not operate correctly. | Smart access system with push-button start (for Entry Function) | Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2021 - 03/2023] |
| Wireless door lock control system | Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2021 - ] | |
| E-latch system | Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2021 - ] | |
| Power distribution box assembly | Refer to REMOVAL [11/2021 - ] | |
| Engine does not start | SFI system | Refer to Engine does not Start [11/2021 - 03/2023] |
| Steering lock function | ||
| Immobiliser function | ||
| Wire harness or connector | ||
| Relay | ||
| Electrical key transmitter sub-assembly | ||
| Stop light switch assembly | ||
| Certification ECU (Smart key ECU assembly) | ||
| New key cannot be registered | LIN communication system | Refer to New Key cannot be Registered [11/2021 - 03/2023] |
| Meter / gauge system | ||
| Reregistration | ||
| Electrical key transmitter sub-assembly | ||
| Steering lock ECU (steering lock actuator with ECU assembly) | ||
| ID code box (Immobiliser code ECU) | ||
| Certification ECU (Smart key ECU assembly) | ||
| Additional key cannot be registered | Smart access system with push-button start (for Start Function) | Refer to Additional Key cannot be Registered [11/2021 - 03/2023] |
| Steering lock function | ||
| Electrical key transmitter sub-assembly | ||
| ID code box (Immobiliser code ECU) | ||
| Certification ECU (Smart key ECU assembly) | ||
| New key registration warning message is not displayed | E-latch system | Refer to New Key Registration Warning Message is not Displayed [11/2021 - ] |
| Meter / gauge system | ||
| Certification ECU (Smart key ECU assembly) | ||
| Unable to unlock steering wheel (Engine cannot start) | Wire harness or connector | Refer to Unable to Unlock Steering Wheel (Engine cannot Start) [11/2021 - 03/2023] |
| Steering lock ECU (steering lock actuator with ECU assembly) | ||
| ID code box (Immobiliser code ECU) | ||
| Certification ECU (Smart key ECU assembly) | ||
| Steering lock does not lock | E-latch system | Refer to Steering Lock does not Lock [11/2021 - 03/2023] |
| Wire harness or connector | ||
| Steering lock ECU (steering lock actuator with ECU assembly) | ||
| ID code box (Immobiliser code ECU) | ||
| Certification ECU (Smart key ECU assembly) | ||
| Security indicator light does not blink | Wire harness or connector | Refer to Security Indicator Light Does not Blink [11/2021 - ] |
| Security indicator light (theft warning indicator light assembly) | ||
| Main body ECU (Multiplex network body ECU) | ||
| Certification ECU (Smart key ECU assembly) | ||
| Immobiliser system does not operate properly | Communication ID registration was defective | Refer to Immobiliser System does not Operate Properly [11/2021 - ] |
| SFI system | ||
| Wire harness or connector | ||
| ID code box (Immobiliser code ECU) | ||
| ECM | ||
| System malfunction message is displayed on the multi-information display | Smart access system with push-button start (for Entry Function) | Refer to System Malfunction Message is Displayed on the Multi-information Display [11/2021 - 03/2023] |
| Smart access system with push-button start (for Start Function) | ||
| Steering lock ECU (steering lock actuator with ECU assembly) | ||
| Certification ECU (Smart key ECU assembly) | ||
| Electronically controlled brake system |