Check LEXUS RX400H 2008 Repair Manual

352
4-3. Do-it-yourself maintenance
RX400h_U
Checking and replacing fuses
If any of the electrical components do not operate, a fuse may have blown.
If this happens, check and replace the fuses as necessary.
Turn the engine switch to the LOCK position.
Remove the engine compartment cover. ( →P. 317)
Open the fuse box cover.
Engine compartment
Push the tabs in and lift the lid
off.STEP1
STEP2
STEP3

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4-3. Do-it-yourself maintenance
4
Maintenance and care
RX400h_U
Driver's side instrument panelRemove the lid.
After a system failure, see “Fuse layout and amperage ratings”
(→ P. 355) for details about which fuse to check.
Remove the fuse with the pull-
out tool.
STEP4
STEP5

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4-3. Do-it-yourself maintenance
RX400h_U
Check if the fuse has blown.Type A
Normal fuse
Blown fuse
Replace it with one of an appro-
priate amperage rating. The
amperage rating can be found
on the fuse box lid.
Type B and C
Type B
Type C
Normal fuse
Blown fuse
Replace it with one of an appro-
priate amperage rating. The
amperage rating can be found
on the fuse box lid.
STEP6

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4-3. Do-it-yourself maintenance
RX400h_U
Headlight aim (vehicles with discharge headlights)
■Vertical movement adjusting screw and bolt
Adjustment screw
Adjustment bolt
■ Before checking the headlight aim
Make sure the vehicle has a full tank of gas and the area around
the headlight is not deformed.
Park the vehicle on level ground.
Sit in the driver’s seat.
Bounce the vehicle several times.
■ Adjusting the headlight aim
Turn the screw in either direc-
tion using a Phillips-head screw-
driver.
Remember the turning direction
and the number of turns in mind.
Turn the bolt the same number
of turns and in the same direc-
tion as step 1 using a Phillips-
head screwdriver.
If the error is over the value
specified above, take the vehicle
to your Lexus dealer to adjust
the headlight aim.
STEP1
STEP2
STEP3
STEP4
STEP1
STEP2

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4-3. Do-it-yourself maintenance
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Maintenance and care
RX400h_U
Light bulbs
You may replace the following bulbs yourself. For more information about
replacing other light bulbs, contact your Lexus dealer.
■Prepare a replacement light bulb.
Check the wattage of the light bulb being replaced. ( →P. 441)
■ Remove the engine compartment cover.
→ P. 317
■ Turn the power back door main switch OFF.
→ P. 4 5
■ Front bulb locations
Parking light Front turn
signal light
Front side
marker light
Headlight
low beam
(halogen bulb)
Headlight
high beam
(halogen bulb)

5
When trouble arises
391
5-2. Steps to take in an emergency
RX400h_U
Follow the correction procedures.After taking the specified steps to co rrect the suspected problem, check
that the warning light turns off.
Warning lightWarning light/DetailsCorrection procedure
Open door warning light
(warning buzzer)
Indicates that one or more of
the doors is not fully closed.
Close the indicated doors.
Low fuel level warning lightRemaining fuel
(Approximately 2.6 gal.
[9.8L, 2.2 Imp.gal.] or less)
Refuel the vehicle.
Driver’s seat belt reminder
light (warning buzzer)*1
Warns the driver to fasten
his/her seat belt.Fasten the seat belt.
Front passenger’s seat belt
reminder light (warning
buzzer)*
2
Warns the front passenger to
fasten his/her seat belt.
Fasten the seat belt.

5
When trouble arises
393
5-2. Steps to take in an emergency
RX400h_U
■Key reminder buzzer
The buzzer indicates that the key has not been removed from the engine switch
(with the engine switch in the ACC or LOCK position and the driver’s door
opened).
■If the malfunction indicator lamp comes on while driving
First check the following:
●Is your vehicle low on gas?
If it is, refuel the vehicle immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The lamp will go off after taking several driving trips.
If the light does not go off even after several trips, contact your Lexus dealer as soon
as possible.
■Front passenger detection sensor and passenger seat belt reminder
●If luggage is placed on the front passenger seat, the front passenger detection
sensor may cause the warning light to flash, even if a passenger is not sitting in the
seat.
●If a cushion is placed on the seat, the sensor may not detect a passenger, and the
warning light may not operate properly.
■Changing the engine oil (U.S.A. only)
Make sure to reset the oil change system. ( →P. 3 2 1 )
■When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level. Pushing the tire
pressure warning reset switch does not turn off the tire pressure warning light.
■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).

394
5-2. Steps to take in an emergency
RX400h_U
■When a tires 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 disabled in the following conditions:
(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 pressure warning select switch is set to a different tire setting.
●If the tire inflation pressure is 73 psi (500 kPa, 5.1 kgf/cm2 or bar) or higher.
The tire pressure warning system may be disabled in the following conditions:
(When the condition becomes normal, the system will work properly.)
●If electronic devices or facilities using similar radio wave frequencies are nearby.
●If a radio set at similar frequencies is in use in the vehicle.
●If a window tint that affects the radio wave signals is installed.
●If there is a lot of snow or ice on the vehicle, in particular around the wheels or
wheel housings.
●If non-genuine Lexus wheels are used. (Even if you use Lexus wheels, the tire
pressure warning system may not work properly with some types of tires.)
●If tire chains are used.
●If the spare tire is in a location subject to poor radio wave signal reception.
●If a large metallic object which can interfere with signal reception is put in the
trunk.
■If the tire pressure warning light comes on after blinking for 1 minute frequently
If the tire pressure warning light comes on after blinking for 1 minute frequently
when the engine switch is turned to ON position, have it checked by your Lexus
dealer.

5
When trouble arises
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5-2. Steps to take in an emergency
RX400h_U
CAUTION
■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 tire. 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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5-2. Steps to take in an emergency
RX400h_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 recommended 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 vehicle 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 and 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).
Your vehicle has also been equipped with a TPMS (tire pressure warning system)
malfunction indicator to indicate when the system is not operating properly. The
TPMS (tire pressure warning system) malfunction indicator is combined with the
low tire pressure telltale (tire pressure warning light). When the system detects a
malfunction, the telltale will flash for approximately one minute and then remain
continuously illuminated. This sequence will continue upon subsequent vehicle
start-ups as long as the malfunction exists. When the malfunction indicator is illumi-
nated, the system may not be able to detect or signal low tire pressure as intended.
TPMS (tire pressure warning system) malfunctions may occur for a variety of rea-
sons, including the installation of replacement or alternate tires or wheels on the
vehicle that prevent the TPMS (tire pressure warning system) from functioning
properly. Always check the TPMS (tire pressure warning system) malfunction tell-
tale after replacing one or more tires or wheels on your vehicle to ensure that the
replacement or alternate tires and wheels allow the TPMS (tire pressure warning
system) to continue to function properly.