2004 Lexus GX470 ECU

IMPORTANT INFORMATION ABOUT YOUR LEXUS
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IMPORTANT INFORMATION
ABOUT YOUR LEXUS
Occupant restraint systems
Lexus encourages you and your family to take the time to read
Section 1-6 of this Owner's Manual carefully. In terms of
helping you understand how you can receive the maximum
benefit of the occupant restraint systems this vehicle provides,
Section 1-6 of this Owner's Manual is the most important
Section for you and your family to read.
Section 1-6 describes the function and operation concerning
seats, seat belts, SRS airbags and child restraint systems of
this vehicle and some potential hazards you should be aware
of. These systems work together along with the overall
structure of this vehicle in order to provide occupant restraint
in the event of a crash. The effect of each system is enhanced
when it is used properly and together with other systems. No
single occupant restraint system can, by itself, provide you or
your family with the equal level of restraint which these
systems can provide when used together. That is why it is
important for you and your family to understand the purpose
and proper use of each of these systems and how they relate
to each other.The purpose of all occupant restraint systems is to help reduce
the possibility of death or serious injury in the event of a
collision. None of these systems, either individually or
together, can ensure that there is no injury in the event of
collision. However, the more you know about these systems
and how to use them properly, the greater your chances
become of surviving an accident without death or serious
injury.
Seat belts provide the primary restraint to all occupants of the
vehicle, and every occupant of the vehicle should wear seat
belts properly at all times. Children should always be secured
in child restraint systems that are appropriate for their age and
size. SRS (Supplemental Restraint System) airbags are, as
their names imply, designed to work with, and be supplemental
to, seat belts and are not substitutes for them. SRS airbags
can be very effective in reducing the risk of head and chest
injuries by preventing contact of the head and chest with
interior portions of the vehicle.
In order to be effective, the SRS airbags must deploy with
tremendous speed. The rapid deployment of the SRS airbags
makes the SRS airbags themselves potential sources of injury
if an occupant is too close to an airbag, or if an object or some
part of his or her body has been placed between the occupant
and the airbag at the time of deployment. This is just one
example of how the instructions in Section 1-6 of this Owner's
Manual will help ensure proper use of the occupant restraint
systems, and increase the safety they can provide to you and
your family in the event of an accident.
Lexus recommends you to read the provisions in Section 1-6
carefully and refer to them from time to time during your time
of ownership of this vehicle.

For detailed information, refer to the description given in each Section.
PICTORIAL INDEX
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Page
1Automatic transmission second start
indicator light 373. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2Unengaged Parkº warning light 61. . . . . . . . . . . . . . .
3Automatic transmission fluid temperature
warning light 62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4Low washer fluid warning light 65. . . . . . . . . . . . . . . . .
5Automatic transmission indicator lights 365. . . . . .
6Driver's seat belt reminder light 58. . . . . . . . . . . . . . . .
7Turn signal indicator light 31. . . . . . . . . . . . . . . . . . . . .
8Brake system warning light 57. . . . . . . . . . . . . . . . . . . .
9Headlight high beam indicator light 31. . . . . . . . . . . .
10ABSº warning light 60. . . . . . . . . . . . . . . . . . . . . . . . . .
11Open door warning light 61. . . . . . . . . . . . . . . . . . . . . . .
12Tachometer 54. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13Headlight indicator light 29. . . . . . . . . . . . . . . . . . . . . . .
14Cruise control indicator light 377. . . . . . . . . . . . . . . .
15Engine oil replacement reminder light 64. . . . . . . . . .
16Engine coolant temperature gauge 52. . . . . . . . . . . . . Page
17Discharge warning light 63. . . . . . . . . . . . . . . . . . . . . . .
18Low engine oil pressure warning light 64. . . . . . . . . .
19Malfunction indicator lamp 59. . . . . . . . . . . . . . . . . . . .
20Slip indicator light 389, 391, 394, 396. . . . . . . . . . . . .
21Vehicle stability control system off
indicator light 391. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22Center differential lock indicator light 373. . . . . . . .
23VSC TRACº warning light 63. . . . . . . . . . . . . . . . . . . . .
24Downhill assist control system
indicator light 393. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25Rear height control indicator lights 386. . . . . . . . . . .
26Security indicator light 14, 26. . . . . . . . . . . . . . . . . . . .
27SRS warning light 59. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28Trip meter reset knob 55. . . . . . . . . . . . . . . . . . . . . . . . .
29Odometer and trip meter 55. . . . . . . . . . . . . . . . . . . . . .
30Low fuel level warning light 65. . . . . . . . . . . . . . . . . . . .
31Fuel gauge 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

KEYS AND DOORS
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Flat key
As a transponder chip is built in its key case, you can start
the engine with this key.
The flat key works in every lock.
A transponder chip for the engine immobilizer system has been
placed in the key case of the flat key. This chip is required for
the system to function correctly, so be careful not to lose this
key. If you make your own duplicate key, you will not be able
to cancel the system or start the engine.
Insert your key plate in its key case as shown. We recommend
that you always carry this with you for emergency use. Do not
leave it in your vehicle.
Starting the engine using a flat key
1. Remove the key plate from the key case.
2. Insert the key plate into the ignition switch. The indicator
light keeps flashing.
3. Bring the key case closer to the ignition switch within 10
seconds as indicated by the arrow head. The indicator light
goes out. This means the engine immobilizer system is
automatically canceled. (For details, see Engine immobilizer
systemº on page 14.) You can put the key case away then. You
cannot cancel the engine immobilizer system if 10 seconds
have past after you inserted the key plate. You need to remove
the key plate from the ignition switch and try it again from the
step 2.
4. Start the engine within 60 seconds after the security
indicator light goes out. You cannot start the engine if 60
seconds have passed after the security indicator went off. You
need to remove the key plate from the ignition switch and try
it again from the step 2.

This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
(1) This device may not cause harmful interference,
and (2) this device must accept any interference
received, including interference that may cause
undesired operation.
KEYS AND DOORS
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ENGINE IMMOBILIZER SYSTEM
The engine immobilizer system is a theft prevention
system. When you insert the key in the ignition switch, the
transponder chip in the key's head transmits an electronic
code to the vehicle. The engine will start only when the
electronic code in the chip corresponds to the registered
ID code for the vehicle.
The system is automatically set when the key is removed from
the ignition switch. At this time, the security indicator light
flashes. When you insert the key in the ignition switch, the
security indicator light goes out and the system is canceled
automatically, which enables the engine to start.
The transponder chip of the flat key is in its key case. You can
cancel the engine immobilizer system using the flat key. (For
details, see Flat keyº on page 9.)For your Lexus dealer to make you a new key with built-in
transponder chip, your dealer will need your key number and
master key. However, there is a limit to the number of
additional keys your Lexus dealer can make for you.
If you make your own duplicate key, you will not be able to
cancel the system or start the engine.
CAUTION
Changes or modifications not expressly approved by
the party responsible for compliance could void the
user's authority to operate the equipment.

KEYS AND DOORS
16The wireless remote control key is an electronic
component. Observe the following instructions in order
not to cause damage to the key.
Do not leave the wireless remote control key on places
where the temperature becomes high such as on the
dashboard.
Do not disassemble it.
Avoid knocking it hard against other objects or dropping it.
Avoid putting it in water.
Locking/Unlocking the doors
When you push the LOCKº button on the key briefly, all
the side doors and back door can be locked from outside
the vehicle.
At this time, you can hear one beep* and the turn signal lights
flash.** However, when you push the LOCKº button with any
door not closed securely, the buzzer sounds for 10 seconds.***
To stop the buzzer, close all the side doors and back door
securely or push the UNLOCKº button. If the key is in the
ignition switch, locking cannot be done.
Make sure all the doors are locked when you leave the vehicle.
Push the LOCKº button once again. If they were already
locked, the turn signal lights will flash.
NOTE:
* The beep volume can be changed.
** The turn signal lights can be set not to flash.
*** The buzzer can be set not to sound if a door is not closed
securely.
Ask your Lexus dealer for details.
When you push the UNLOCKº button, the driver's door
is unlocked. Pushing that button once again within 3
seconds from the first push, all other side doors and back
door are also unlocked.*
NOTE:
* The 2-step unlocking function can be changed.
Ask your Lexus dealer for details.
At this time, you can hear two beeps* and the turn signal lights
flash twice.** Together with the activation of unlocking, the
personal lights and center interior light come on for 15 seconds
if the personal light switch and center interior light switch is in
the DOORº position and the running board lights come on for
15 seconds.*** However, this function does not work when the
ignition key is in the ONº position. For further information, see
Illuminated entry systemº on page 78.
You have 30 seconds to open a door after using the wireless
remote unlock feature.**** If a door is not opened by then, all
the doors will be automatically locked again.
Even if the LOCKº or UNLOCKº button is kept pressed in, the
locking or unlocking operation is not repeated. Release the
button and then push again.
NOTE:
* The beep volume can be changed.
** The turn signal lights can be set not to flash.
*** The personal lights, center interior light and running
board lights can be set not to come on or the duration of
lighting can be changed.
**** The time before automatic re-locking can be changed.
Ask your Lexus dealer for details.

KEYS AND DOORS
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NOTICE

Make sure the positive side and negative side of the
battery are faced correctly.

Do not replace the battery with wet hands. Water may
cause unexpected rust.

Do not touch or move any components in the
transmitter, or it may interfere with proper operation.

Be careful not to bend the electrode of the battery
insertion and that dust or oils do not adhere to the
inside of the module.

Take care not to lose the screws and O-ring.
5. Install the lid with the 2 screws.
NOTICE
Take care not to damage or bend the O-ring when
installing.
6. Install the module into the key frame and secure the cover
with the screw.
7. When pushing any switch on the wireless key, make sure
the indicator light comes on.SIDE DOORS
Locking with key

KEYS AND DOORS
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Security indicator light
Setting the system
1. Turn the ignition key to the LOCKº position and
remove it.
The engine immobilizer system causes the indicator light to
flash.
2. Close and lock all the doors and hood using an ignition
key or wireless remote control.
If you lock them with wireless remote control, the turn signals
flash once.
The flashing indicator light will remain on when all the doors
and hood are closed and locked.
3. After 30 seconds, the indicator starts flashing and the
system is set.
Cancelling the system
When you unlock any door using an ignition key or
wireless remote control, the system is cancelled.
If you unlock any door with wireless remote control, the turn
signals flash twice.
Activating the system
The alarm sounds for 60 seconds if any of the following are
operated:
Unlocking any door without using an ignition key or wireless
remote control.
Opening the hood and any doors forcibly.
Reconnecting the battery.
If the battery becomes discharged due to the vehicle being
unused for a long time, etc., when the battery is recharged or
replaced, the system will give the alarm. If this happens,
immediately unlock any of the doors with the key or the
wireless remote control, and the alarm will stop.
If any door is unlocked and the ignition key is not in the ignition
switch during the alarm sounding, its door is automatically
locked.
To stop the alarm: Use either of the following methods.
Unlock the door using an ignition key or wireless remote
control.
Turn the ignition switch on.

GAUGES, METERS AND SERVICE REMINDER INDICATORS
59
(d) SRS Warning Light
The indicator comes on when the ignition key is turned to
the ONº position. It goes off after about 6 seconds. This
means the SRS airbags and front seat belt pretensioners
are operating properly.
This warning light system monitors the airbag sensor
assembly, front airbag sensors, side and curtain shield airbag
sensor assemblies, curtain shield airbag sensor assemblies,
driver's seat position sensor, driver's seat belt buckle switch,
front seat belt pretensioner assemblies, inflators, warning light,
interconnecting wiring and power sources.
If either of the following conditions occurs, this indicates a
malfunction somewhere in the parts monitored by the warning
light system. Contact your Lexus dealer as soon as possible
to service the vehicle.
When the ignition key is turned to the ONº position, the light
does not come on, remains on or flashes.
The light comes on or starts flashing while driving.
If the light stays on, it indicates that the driver and front
passenger airbags have a problem. If the light flashes, the side
and curtain shield airbags and/or seat belt pretensioners have
a problem.
(e) Malfunction Indicator Lamp
This lamp comes on when the ignition key is turned to the
ONº position and goes off after the engine starts. This
means that the warning light system is operating properly.
If the lamp remains on, or the lamp comes on while driving,
first check the followings.
Empty fuel tank
If the fuel tank is empty, refuel immediately.
Loose fuel tank cap
If the fuel tank cap is loose, securely tighten it.
These cases are temporary malfunctions. The malfunction
indicator lamp will go off after taking several driving trips.
If the lamp will not go off even after the several trips, contact
your Lexus dealer as soon as possible.
If the fuel tank is not empty or the fuel tank cap is not
loose...
There is a problem somewhere in the engine, emission
control system, electronic throttle control system, automatic
transmission electrical system or warning light system itself.
Contact your Lexus dealer as soon as possible to service the
vehicle.
If the engine speed does not increase with the accelerator
pedal depressed down, there may be a problem somewhere
in your electronic throttle control system.