Lexus RX300 (MCU15). Service manual - part 68

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BODY ELECTRICAL — ACCESSORIES

145

Operation

D When a door is locked through the operation of the transmitter, it locks in the normal manner; further-

more, the sub lever becomes disengaged by the function of the double locking motor. As a result, if an
attempt is made to unlock the door by operating the inside knob, the sub lever will merely mis-swing,
without being able to unlock the door.

D The locking/unlocking function of the double locking system is normally activate by operating the trans-

mitter. However, as an emergency unlocking maneuver, only the driver’s door can be unlocked with a
key.

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Normal Lock Condition

Double Lock Condition

BODY ELECTRICAL — ACCESSORIES

Service Tip

In case of making new ignition key due to the loss of it, it is necessary to register recognition code.
Refer to see the LEXUS RX300 Repair Manual (Pub. No. RM785E).

146

JWIRELESS DOOR LOCK REMOTE CONTROL SYSTEM

1. General

The wireless door lock remote control system is a convenient system for locking and unlocking all the
doors, at a distance. This system in the RX300 has the following features:

D In this system, the wireless door control receiver performs the code identification process and the body

ECU effects the door lock control. Serial data link is provided for communication between the wireless
door control receiver and the body ECU. The body ECU outputs signals to the respective ECUs via
the BEAN. Upon receiving the signals, the ECUs operate the respective actuators. However, the control
of the back door is effected by the body ECU, which operates the actuator.

D A key-integrated, two-button (lock, unlock) type transmitter has been adopted.

D A rolling code system, in which the signal configuration changes each time when a signal is transmitted

by the transmitter, has been adopted.

D The hazard light is flashed once when locking, and the hazard light is flashed twice when unlocking,

to inform that the operation has been completed.

" System Diagram A

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Transmitter

BEAN

Key Unlock
Warning
Switch

Body
ECU

Back Door
Courtesy
Switch

Serial Data Link

Door
Control
Receiver

Back Door
Lock
Motor

Hazard
Lamp Relay

Double
Lock
ECU

Driver
Door
ECU

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BODY ELECTRICAL — ACCESSORIES

147

2. Construction

Transmitter

A key-integrated, two-button (lock, unlock) type transmitter has been adopted.
This transmitter is equipped with an LED display function to monitor the condition of the battery. Further-
more, its construction allows the key molded portion and the transmitter body to be separated completely
for improved serviceability.

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LED

LED

Transmitter
Body

Door Unlock
Switch

Door Lock Switch

Front Side

Reverse Side

Door Lock
Switch

Door Unlock
Switch

Side View

Front View

Transmitter Body

3. Function

General

The wireless door lock remote control system in the RX300 has the following functions.

Function

Outline

All Doors Lock or
Unlock Operation

Pressing the door lock switch or the door unlock switch locks or unlocks
all the doors. The hazard light is flashed once when locking, and the hazard
light is flashed twice when unlocking, to inform that the operation has
been completed.

Auto Lock Function

If none of the doors are opened within approximately 30 seconds after they
are unlocked by the wireless door lock remote control, all the doors are
locked again automatically.

Illuminated Entry
Function

When all the driver’s doors are locked, pressing the “door unlock” switch
causes the interior lights to illuminate simultaneously with the unlock op-
eration.

Transmitter Switch
Misoperation
Prevention Function

When an ignition key is in the ignition key cylinder or any of the doors is
not closed completely, the wireless door lock remote control is temporari-
ly cancelled to prevent misoperation. However, unlock can be operated
when with any door opened.

Security Function

Send an operation signal as a rolling code.

Repeat Function

If no changes occur in the lock condition when the door lock switch is
pressed once, this function causes the body ECU to output a lock signal
once again.

Transmitter Recognition
Code Registration
Function

Enables the registering (writing and storing) of 4 types of transmitter rec-
ognition code in the EEPROM that is contained in the door control receiv-
er.

BODY ELECTRICAL — ACCESSORIES

Service Tip

In case of making new ignition key due to the loss of it, it is necessary to register ID code.
Refer to see the LEXUS RX300 Repair Manual (Pub. No. RM785E).

148

Transmitter Recognition Code Registration Function

The table below shows the 4 special coded ID registration function modes through which up to 4 different
codes can be registered. The codes are electronically registered (written to and stored) in the EEPROM.
For details of the recognition code registration procedure, refer to the LEXUS RX300 Repair Manual
(Pub. No. RM785E) to register the codes correctly.

Mode

Function

Rewrite Mode

Erases all previously registered codes and registers only the newly received codes.
This mode is used whenever a transmitter or the body ECU is replaced.

Add Mode

Adds a newly received code while preserving any previously registered codes.
This mode is used when adding a new transmitter. If the number of codes exceeds
4, the oldest registered code is erased first.

Confirm Mode

Confirms how many codes are currently registered. When adding a new code, this
mode is used to check how many codes already exist.

Prohibit Mode

To delete all the registered codes and to prohibit the wireless door lock function.
This mode is used when the transmitter is lost.

JENGINE IMMOBILISER SYSTEM

The engine immobiliser system is theft deterrent system which disables the engine from starting using
the ignition key with an ID code that matched is the pre-registered code in the vehicle. This system consists
of the transponder chip, coil, amplifier, and immobiliser ECU. The immobiliser ECU is enclosed in the
engine ECU. This system adopts a transponder system which uses a transponder chip embedded in the
grip of the ignition key. When the coil located around the ignition key cylinder receives the ID code signal
transmitted by the transponder chip, the engine ECU determines whether or not the ID code matches the
code stored.

" System Diagram A

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Ignition
Key

Transponder Chip

Key
Cylinder

Engine
ECU

Spark Plug

Injector

Indicator
Light

Transponder
Key Amplifier

Transponder
Key Coil