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4-3. Do-it-yourself maintenance
GX460_OM_OM60J63U_(U)
■When replacing wheels
The wheels of your Lexus are equipped with tire pressure warning valves and trans-
mitters that allow the tire pressure warning system to provide advanced warning in
the event of a loss in tire inflation pressure. Whenever wheels are replaced, the tire
pressure warning valves and transmitters must be installed. ( P. 6 3 7 )
CAUTION
■When replacing wheels
●Do not use wheels that are a different size from those recommended in the
Owner’s Manual, as this may result in loss of handling control.
●Never use an inner tube in a leaking wheel which is designed for a tubeless tire.
Doing so may result in an accident, causing death or serious injury.
■When installing the wheel nuts
●Never use oil or grease on the wheel bolts or wheel nuts.
Oil and grease may cause the wheel nuts to be excessively tightened, leading to
bolt or disc wheel damage. In addition, the oil or grease can cause the wheel nuts
to loosen and the wheel may fall off, causing an accident and resulting in death or
serious injury. Remove any oil or grease from the wheel bolts or wheel nuts.
●Be sure to install the wheel nuts with the
tapered ends facing inward. Installing the
nuts with the tapered ends facing outward
can cause the wheel to break and eventu-
ally cause the wheel to come off while driv-
ing, which could lead to an accident
resulting in death or serious injury.
Ta p e r e d
portion
Page 683 of 844

When trouble arises5
683
GX460_OM_OM60J63U_(U)
5-1. Essential informationEmergency flashers............... 684
If your vehicle needs to be towed ............................ 685
If you think something is wrong ....................................... 691
Fuel pump shut off system.... 692 5-2. Steps to take in an
emergency
If a warning light turns on or a warning buzzer
sounds..................................... 693
If a warning message is displayed................................ 705
If you have a flat tire................ 726
If the engine will not start ..... 740
If the shift lever cannot be shifted from P ........................ 742
If you lose your keys ............... 743
If the electronic key does not operate properly........... 744
If the vehicle battery is discharged ............................. 746
If your vehicle overheats ...... 749
If the vehicle becomes stuck........................................ 752
If your vehicle has to be stopped in an
emergency ............................ 754
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5
When trouble arises
691
5-1. Essential information
GX460_OM_OM60J63U_(U)
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact your Lexus dealer as soon as possible.
■Visible symptoms
●Fluid leaks under the vehicle
(Water dripping from the air conditioning after use is normal.)
● Flat-looking tires or uneven tire wear
● Engine coolant temper ature gauge needle continually points
higher than normal
■ Audible symptoms
●Changes in exhaust sound
● Excessive tire squeal when cornering
● Strange noises related to the suspension system
● Pinging or other noises related to the engine
■ Operational symptoms
●Engine missing, stumbling or running roughly
● Appreciable loss of power
● Vehicle pulls heavily to one side when braking
● Vehicle pulls heavily to one side when driving on a level road
● Loss of brake effectiveness, sp ongy feeling, pedal almost touches
the floor
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5-2. Steps to take in an emergency
GX460_OM_OM60J63U_(U)
*1: Open door warning buzzer:
The open door warning buzzer sounds to alert one or more of the doors is not
fully closed (with the vehicle having reached a speed of 3 mph [5 km/h]).
( P. 7 0 9 )
*2: Driver’s and front passenger’s seat belt reminder buzzer:
The driver’s and front passenger’s seat belts reminder buzzer sounds to alert
the driver and front passenger that his/he r seat belt is not fastened. Once the
“ENGINE START STOP” switch is turned to IGNITION ON mode, the buzzer
sounds for 4 to 8 seconds. If the vehi cle reaches a speed of 12 mph (20 km/h),
the buzzer sounds intermittently for 10 seconds. Then, if the seat belt is still
unfastened, the buzzer will sound in a different tone for 20 more seconds.
Warning lightWarning light/DetailsCorrection procedure
Master warning light
A buzzer sounds and the
warning light comes on and
flashes to indicate that the
master warning system has
detected a malfunction.
P. 7 0 5
Tire pressure warning light
When the light comes on:
Low tire inflation pressure.Adjust the tire inflation pres-
sure.
When the light comes on after
blinking for 1 minute:
Malfunction in the tire pres-
sure warning system.
Have the system checked by
your Lexus dealer.
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5-2. Steps to take in an emergency
GX460_OM_OM60J63U_(U)
■When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level.
■The tire pressure warning light may turn on due to natural causes
The tire pressure warning light may turn on due to natural causes such as natural air
leaks or tire inflation pressure changes caused by temperature. In this case, adjust-
ing the tire inflation pressure will turn off the warning light (after a few minutes).
■When a tire is replaced with a spare tire
The spare tire is also equipped with the tire pressure warning valve and transmitter.
The tire pressure warning light will turn on if the tire inflation pressure of the spare
tire is low. If a tire goes flat, even though the flat tire is replaced with the spare tire,
the tire pressure warning light does not turn off. Replace the spare tire with the
repaired tire and adjust the proper tire inflation pressure. The tire pressure warning
light will turn off after a few minutes.
■If the tire pressure warning system is inoperative
The tire pressure warning system will be come inoperative in the following condi-
tions:
(When the condition becomes normal, the system will work properly.)
●If tires not equipped with tire pressure warning valves and transmitters are used.
●If the ID code on the tire pressure warning valves and transmitters is not regis-
tered in the tire pressure warning computer.
●If the tire inflation pressure is 73 psi (500 kPa, 5.1 kgf/cm2 or bar) or higher.
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5-2. Steps to take in an emergency
GX460_OM_OM60J63U_(U)
CAUTION
■If both the ABS and the brake system warning lights remain on
Stop your vehicle in a safe place immediately and contact your Lexus dealer. The
vehicle will become extremely unstable during braking, and the ABS system may
fail, which could cause an accident resulting in death or serious injury.
■When the power steering system warning light comes on
The steering wheel may become extremely heavy.
If the steering wheel becomes heavier than usual when operating, hold firmly and
operate using more force than usual.
■If the tire pressure warning light comes on
Be sure to observe the following precautions. Failure to do so could cause loss of
vehicle control and result in death or serious injury.
●Stop your vehicle in a safe place as soon as possible. Adjust the tire inflation pres-
sure immediately.
●If the tire pressure warning light comes on even after tire inflation pressure adjust-
ment, it is probable that you have a flat ti re. Check the tires. If the tire is flat,
change to the spare tire and have the flat tire repaired by the nearest Lexus
dealer.
●Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, you could
lose control of the steering wheel or the brakes.
■If a blowout or sudden air leakage should occur
The tire pressure warning system may not activate immediately.
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When trouble arises
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5-2. Steps to take in an emergency
GX460_OM_OM60J63U_(U)
CAUTION
■Maintenance of the tires
Each tire, including the spare (if provided), should be checked monthly when cold
and inflated to the inflation pressure re commended by the vehicle manufacturer on
the vehicle placard or tire inflation pressure label (tire and load information label).
(If your vehicle has tires of a different size than the size indicated on the vehicle
placard or tire inflation pressure label [tire and load information label], you should
determine the proper tire inflation pressure for those tires.)
As an added safety feature, your vehicl e has been equipped with a tire pressure
monitoring system (TPMS-tire pressure warning system) that illuminates a low tire
pressure telltale (tire pressure warning light) when one or more of your tires is sig-
nificantly under-inflated. Accordingly, when the low tire pressure telltale (tire pres-
sure warning light) illuminates, you should stop and check your tires as soon as
possible, and inflate them to the proper pressure. Driving on a significantly under-
inflated tire causes the tire to overheat an d can lead to tire failure. Under-inflation
also reduces fuel efficiency and tire tread life, and may affect the vehicle’s handling
and stopping ability.
Please note that the TPMS (tire pressure warning system) is not a substitute for
proper tire maintenance, and it is the driver’s responsibility to maintain correct tire
pressure, even if under-inflation has not reached the level to trigger illumination of
the TPMS low tire pressure telltale (tire pressure warning light).
Page 726 of 844
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5-2. Steps to take in an emergency
GX460_OM_OM60J63U_(U)
If you have a flat tire
Remove the flat tire and replace it with the spare provided.
■Before jacking up the vehicle
●Stop the vehicle on a hard, flat surface.
● Set the parking brake.
● Shift the shift lever to P.
● Vehicles with rear height cont rol air suspension: Turn off the
height control. ( P. 320)
● Stop the engine.
● Turn on the emergency flashers. ( P. 684)
■ Location of the spare tire, jack and tools
Spare tire
Jack
To o l b o x