Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: System Description

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual / Vehicle Interior / Door Lock / Wireless Door Lock Control System / System Description

SYSTEM DESCRIPTION

WIRELESS DOOR LOCK CONTROL SYSTEM

The wireless door lock control system can be used to lock and unlock all doors from a distance. The system is controlled by an electrical key transmitter sub-assembly which sends radio waves to the electrical key and tire pressure monitoring system receiver assembly. The certification ECU (smart key ECU assembly) performs an ID code identification process and operates the door lock control.

MULTI CHANNEL FUNCTION

The wireless door lock control system has a multi channel function. Each time the switch on the electrical key transmitter sub-assembly is pressed, the channel is switched alternately between 2 different frequencies and the signal is sent to the electrical key and tire pressure monitoring system receiver assembly.

FUNCTION OF MAIN COMPONENTS

Component

Function

Electrical key transmitter sub-assembly
  • Has the lock, unlock, back door open and panic switches.
  • Transmits weak radio waves (recognition codes and function codes) to the electrical key and tire pressure monitoring system receiver assembly.
  • Illuminates the indicator light (LED) during transmission.

Electrical key and tire pressure monitoring system receiver assembly

Receives weak radio waves from the electrical key transmitter sub-assembly and sends them to the certification ECU (smart key ECU assembly).
  • Front door courtesy light switch assembly (for LH/RH)
  • Rear door courtesy light switch assembly (for LH/RH)
  • Back door courtesy switch
  • Turns on when a door is opened and turns off when it is closed.
  • Outputs door status signals (open or closed) to the main body ECU (multiplex network body ECU).
  • Front door lock with motor assembly LH/RH
  • Rear door lock assembly LH/RH
  • Has a built-in motor that locks or unlocks the door.
  • Transmits the door lock position of each door to the main body ECU (multiplex network body ECU).

Certification ECU (Smart key ECU assembly)

Sends wireless door lock control signals in response to the code data from the electrical key and tire pressure monitoring system receiver assembly and signals from each ECU.

SYSTEM FUNCTION

The electrical key transmitter sub-assembly has lock, unlock, back door open, panic switches. Operating these switches activates each function.

The wireless door lock control system has the following functions:

HINT:

The default setting of the following functions is on. Part of these functions can be customized.

Click here

Function

Operation

All door lock

Pressing the lock switch locks all of the doors.

All door unlock

(Unlock 2 operation)

Pressing the unlock switch twice within 5 seconds unlocks all of the doors after the driver door is unlocked.

Back door open

Pressing the back door open switch of the electrical key transmitter sub-assembly for longer than approximately 0.8 seconds opens the back door.

Automatic lock

If none of the doors is opened within 60 seconds after they are unlocked by the wireless door lock control, all of the doors will lock again automatically.

Answer-back (Hazard warning light)
  • When the doors are locked by wireless operation, the hazard warning lights flash once.
  • When the doors are unlocked by wireless operation, the hazard warning lights flash twice.

Answer-back (Wireless door lock buzzer)
  • When the doors are locked by wireless operation, the wireless door lock buzzer sounds once.
  • When the doors are unlocked by wireless operation, the wireless door lock buzzer sounds twice.
  • When the back door is opened by wireless operation, the wireless door lock buzzer sounds.

Panic alarm

Pressing the panic switch of the electrical key transmitter sub-assembly for longer than approximately 0.8 seconds causes the following alarms to activate:

  • Sounds the vehicle horns and security horn.
  • Blinks the headlights, hazard warning lights and taillights.
  • Illuminates the interior lights.

While the panic alarm is operating, pressing any switch of the electrical key transmitter sub-assembly cancels the alarm operation.

Door ajar warning

The buzzer sounds for 5 seconds continuously when the lock switch is pressed when any of the doors are ajar. The buzzer stops when all of the doors are closed or the unlock switch is pressed.

Illuminated entry

When all of the doors are locked, pressing the unlock switch causes the interior lights to come on simultaneously with the unlock operation.

Self-diagnostic mode

If the electrical key and tire pressure monitoring system receiver assembly receives normal radio waves from the electrical key transmitter sub-assembly when the system is in diagnostic mode, it sounds the wireless door lock buzzer in a normal pattern that corresponds to the function of each switch.
    Precaution
    PRECAUTION PRECAUTION FOR DISCONNECTING CABLE FROM NEGATIVE BATTERY TERMINAL NOTICE: When disconnecting the cable from the negative (-) battery terminal, initialize the following systems after the cab ...

    System Diagram
    SYSTEM DIAGRAM Communication Table Sender Receiver Signal Line Certification ECU (Smart Key ECU Assembly) Main Body ECU (Multiplex Network Body ECU) Wireless door lock/unlock s ...

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    Lexus RX (RX 350L, RX450h) 2016-{YEAR} Owners Manual

    Lexus RX (RX 350L, RX450h) 2016-{YEAR} Repair Manual

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