Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: How To Proceed With Troubleshooting

HINT:

• Use these procedures to troubleshoot the smart access system with push-button start (for Entry Function).
• *: Use the Techstream.

HINT:

• In troubleshooting, confirm that the problem symptoms have been accurately identified. Preconceptions should be discarded in order to make an accurate judgment. To clearly understand what the problem symptoms are, it is extremely important to ask the customer about the problem and the conditions at the time the malfunction occurred.
• Gather as much information as possible for reference. Past problems that seem unrelated may also help in some cases.
• The following 5 items are important points for problem analysis:

  What?	Vehicle model, system name
  When?	Date, time, occurrence frequency, whether the problem occurred recently or has been occurring for a long time
  Where?	Whether the problem occurs at a specific location
  Under what conditions?	Whether the doors were locked or unlocked, whether the engine switch was on, whether the engine was running
  How did it happen?	Problem symptoms*

  • *: Be sure to ask the customer in detail about the following points concerning the vehicle operating conditions, environment and problem, and then check for DTCs.
    1. If the entry lock/unlock function does not operate for all doors.
    2. If the entry lock function does not operate.
    3. If the entry unlock function does not operate.
    4. If both the entry lock and unlock functions do not operate.
    5. If the wireless lock and unlock functions do not operate.
    6. If there is no power even when the engine switch is pressed (engine switch does not turn on (ACC)).
    7. If the engine does not start with the push-button start function.
    8. If the outside warning buzzers do not sound.
    9. If an engine start was attempted by holding the electrical key transmitter sub-assembly near the engine switch and then pressing the engine switch.
    10. If the interior warning buzzers do not sound.
    11. If the steering does not unlock.
    12. Any other details concerning the problem.
  • If it is suspected that wave interference is likely, be sure to ask the customer in detail about the following points concerning the vehicle operating conditions, environment and problem.
    1. Specific locations where the system does not operate (such as near TV towers, large video displays, wireless garage door opener systems, wireless security cameras, home security systems, etc.).
    2. Specific times when the system does not operate: If the symptoms occurred immediately after purchase or only recently. If the symptoms occurred when the electrical key transmitter sub-assembly was near the vehicle (electrical key antenna).
    3. If the system does not operate only when near specific vehicles (there may be wave interference from the wireless systems of other vehicles).
    4. If the system operates intermittently.
    5. If the electrical key transmitter sub-assembly is bundled together with other items.
    6. If the electrical key transmitter sub-assembly is carried together with other electronic devices, such as cell phones, personal computers, portable music players, other electrical key transmitter sub-assemblies, etc. (keep the electrical key transmitter sub-assembly at least 0.1 m (0.328 ft.) away from such items).
    7. Where the electrical key transmitter sub-assembly is being kept when not in use: If the electrical key transmitter sub-assembly is being placed within 1 m (3.28 ft.) of items such as TVs, DVD recorders, induction cookers, rice cookers, dishwashers, modems, cell phones, personal computers, microwave ovens, desk or floor lamps, cordless telephones, etc.
    8. If there are electronic devices that transmit radio waves placed in the vehicle.
    9. When the transmitter battery was last replaced. The transmitter battery can be checked roughly using the "Key Low Battery" item in the Data List.

       Click here

    10. If the steering does not unlock.
    11. If the customer installed any optional components (theft deterrent devices, wireless fog lights, etc.) to the vehicle.

System Description

Operation Check

Other materials:

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual > Rear Power Seat Control System(for Third Row): Park / Neutral Position Switch Circuit
DESCRIPTION Each fold seat control ECU receives the driving condition signal and engine switch signal from the main body ECU (multiplex network body ECU) to determine the driving state of the vehicle and enable or disable the fold and return functions. WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE ...

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual > Lighting System (w/ Automatic Headlight Beam Level Control System): Variation Code not Written (B2451)
DESCRIPTION The No. 1 headlight ECU sub-assembly LH stores this DTC if the vehicle specifications have not been stored. DTC No. Detection Item DTC Detection Condition Trouble Area DTC Output from B2451 Variation Code not Written The engine switch is on (IG). Vehicle speci ...