air condition LEXUS RX450h 2018 Workshop Manual

616 7-3. Do-it-yourself maintenance
RX450h_RX450hL _U_OM48F85U■
Situations in which the tire pressure warning system may not operate properly ●
In the following cases, the tire pressure warning system may not operate properly.
• If non-genuine Lexus wheels are used.
• A tire has been replaced with a tire that is not an OE (Original Equipment) tire.
• A tire has been replaced with a tire that is not of the specified size.
• Tire chains, etc. are equipped.
• If a window tint that affects th e radio wave signals is installed.
• If there is a lot of snow or ice on the vehi cle, particularly around the wheels or wheel
housings.
• If the tire inflation pressure is extr emely higher than the specified level.
• If wheel without the tire pressure warning valve and transmitter is used.
• If the ID code on the tire pressure warning valves and transmitters is not registered
in the tire pressure warning computer. ●
Performance may be affected in the following situations.
• Near a TV tower, electric power plant, gas station, radio station, large display, air-
port or other facility that generates st rong radio waves or electrical noise.
• When carrying a portable radio, cellular phone, cordless phon e or other wireless
communication device.
If tire position information is not correctl y displayed due to the radio wave conditions,
the display may be corrected by driving and changing the radio wave conditions. ●
When the vehicle is parked, the time taken for the warning to start or go off could be
extended. ●
When tire inflation pressure declines rapidly for example when a tire has burst, the
warning may not function. ■
The initialization operation ●
Make sure to carry out initialization afte r adjusting the tire inflation pressure.
Also, make sure the tires are cold before carryi ng out initialization or tire inflation pres-
sure adjustment. ●
If you have accidentally turned the power switch off during in itialization, it is not neces-
sary to press the reset switch again as initialization will re start automatically when the
power switch has been turned to ON mode for the next time. ●
If you accidentally press the re set switch when initialization is not necessary, adjust the
tire inflation pressure to the specified leve l when the tires are co ld, and conduct initial-
ization again. ●
While the position of each tire is being de termined and the inflation pressures are not
being displayed on the multi-info rmation display, if the inflat ion pressure of a tire drops,
the tire pressure warning light will come on.

6197-3. Do-it-yourself maintenance
7
Maintenance and care
RX450h_RX450hL _U_OM48F85UWARNING ■
When inspecting or replacing tires
Observe the following precautions to prevent accidents.
Failure to do so may cause damage to parts of the drive train as well as dangerous han-
dling characteristics, which may lead to an accident resu lting in death or serious injury.●
Do not mix tires of different makes, models or tread patterns.
Also, do not mix tires of remarkably different treadwear. ●
Do not use tire sizes other than those recommended by Lexus. ●
Do not mix differently constructed tires (radial, bias-belted or bias-ply tires). ●
Do not mix summer, all season and snow tires. ●
Do not use tires that have be en used on another vehicle.
Do not use tires if you do not know how they were used previously. ●
Do not tow if your vehicle has a compact spare tire installed. ■
When initializing the tire pressure warning system
Do not initializing tire inflatio n pressure without first adjusting the tire inflation pressure
to the specified level. Otherwise, the tire pressure warning light may not come on even
if the tire inflation pressure is low, or it may come on when the tire inflation pressure is
actually normal.
NOTICE ■
Repairing or replacing tires, wheels, tire pressure warning valv es, transmitters and
tire valve caps ●
When removing or fitting the wheels, tires or the tire pressure warning valves and
transmitters, contact your Lexus dealer as the tire pressure warning valves and trans-
mitters may be damaged if not handled correctly. ●
Make sure to install the tire valve caps. If the tire valve caps ar e not installed, water
could enter the tire pressure warning valves and the tire pressure warning valves
could be bound. ●
When replacing tire valve caps, do not use tire valve caps other than those specified.
The cap may become stuck. ■
To avoid damage to the tire pressu re warning valves and transmitters
When a tire is repaired with liquid sealants, the tire pressure warning valve and trans-
mitter may not operate properly. If a liquid sealant is used, contact your Lexus dealer or
other qualified service shop as soon as possi ble. Make sure to replace the tire pressure
warning valve and transmitter when replacing the tire. ( → P. 612)■
Driving on rough roads
Take particular care when driving on roads with loose surfaces or potholes.
These conditions may cause lo sses in tire inflation pre ssure, reducing the cushioning
ability of the tires. In addition, driving on rough roads may cause damage to the tires
themselves, as well as the vehicle’s wheels and body. ■
If tire inflation pressure of ea ch tire becomes low while driving
Do not continue driving, or your tires and/or wheels may be ruined.

622 7-3. Do-it-yourself maintenance
RX450h_RX450hL _U_OM48F85U■
Instructions for checking tire inflation pressure
When checking tire in flation pressure, ob serve the following:●
Check only when the tires are cold.
If your vehicle has been parked for at least 3 hours or has not been driven for more than
1 mile or 1.5 km, you will get an accurate cold tire inflation pressure reading. ●
Always use a tire pressure gauge.
It is difficult to judge if a tire is properly inflated based only on its appearance. ●
It is normal for the tire inflat ion pressure to be higher after driving as heat is generated
in the tire. Do not reduce tire inflation pressure after driving.●
Never exceed the vehicle capacity weight.
Passengers and luggage weight should be placed so that the vehicle is balanced.
WARNING ■
Proper inflation is critical to save tire performance
Keep your tires properly inflated.
If the tires are not properly inflated, the following conditions may occur which could
lead to an accident resultin g in death or serious injury:●
Excessive wear ●
Uneven wear ●
Poor handling ●
Possibility of blowouts resu lting from overheated tires●
Air leaking from between tire and wheel ●
Wheel deformation and/or tire damage ●
Greater possibility of tire damage while driving (due to road hazards, expansion
joints, sharp edges on the road, etc.)
NOTICE ■
When inspecting and adjust ing tire inflation pressure
Be sure to put the tire valve caps back on.
If a valve cap is not installed, dirt or moisture may get into the valve and cause an air
leak, resulting in decreased tire inflation pressure.

6257-3. Do-it-yourself maintenance
7
Maintenance and care
RX450h_RX450hL _U_OM48F85UTurn the power switch off.
Open the glove box. Slide off the
damper.
Push in the glove box on the vehi-
cle's outer side to disconnect the
claws. Then pull out the glove box
and disconnect the lower claws.
Remove the cover.Air conditioning filter The air conditioning filter must be ch anged regularly to maintain air condi-
tioning efficiency.
Removal method 1
2
3
4

626 7-3. Do-it-yourself maintenance
RX450h_RX450hL _U_OM48F85URemove the filter cover.
Unlock the filter cover.
Move the filter cover in the direc-
tion of the arrow, and then pull it
out of the claws.
Remove the filter case. There may be foreign objects on top of
the air conditioning filter.
Remove the air conditioning filter
from the filter case and replace it
with a new one. The “ ↑ UP” marks shown on the filter
and the filter case sh ould be pointing up.
■
Checking interval
Inspect and replace the air cond itioning filter according to the maintenance schedule. In
dusty areas or areas with heavy traffic fl ow, early replacement may be required. (For
scheduled maintenance informat ion, please refer to the “Owner’s Manual Supplement”
or “Scheduled Maintenance”.) ■
If air flow from the vents decreases dramatically
The filter may be clogged. Check the filter and replace if necessary. ■
Air conditioning filter with deodorizing function
When fragrances are placed in your vehicle, the deodorizing effect may become signifi-
cantly weakened in a short period.
When an air conditioning odor comes out cont inuously, replace the air conditioning filter.5
1
2
6
7

6277-3. Do-it-yourself maintenance
7
Maintenance and care
RX450h_RX450hL _U_OM48F85UNOTICE ■
When using the air conditioning system
Make sure that a filter is always installed.
Using the air conditioning system without a filter may cause damage to the system.■
To prevent damage to the filter cover
When moving the filter cover in the direction of
arrow to release the fitting, pay attention not to
apply excessive force to the claws. Otherwise,
the claws may be damaged.

6658-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85U■
The tire pressure warning light ma y come on due to natural causes
The tire pressure warning light may come on due to natural causes such as natural air
leaks and tire inflation pressure changes caus ed by temperature. In this case, adjusting
the tire inflation pressure will turn off the warning light (aft er a few minutes).■
When a tire is replaced with a spare tire
The compact spare tire is not equipped with a tire pressure warning valve and transmit-
ter. If a tire goes flat, the tire pressure warning light will not turn off even though the flat
tire has been replaced with the spare tire. Replace the spare tire with the repaired tire
and adjust the tire inflation pressure. The tire pressure warnin g light will go off after a few
minutes. ■
Conditions that the tire pressure wa rning system may not function properly
→ P. 616 ■
Warning buzzer
In some cases, the buzzer ma y not be heard due to being in a noisy location or audio
sound. ■
Customization
Some functions can be customized. ( → P. 736)
WARNING ■
If both the ABS and the brake sy stem warning lights remain on
Stop your vehicle in a safe place immediat ely and contact your Lexus dealer. The vehi-
cle will become extremely unstable during br aking, and the ABS system may fail, which
could cause an accident resultin g in death or serious injury.■
When the electric power steering system warning light comes on
When the light comes on yellow, the assist to the power steering is restricted. When the
light comes on red, the assist to the power steering is lost and ha ndling operations of
the steering wheel become extremely heavy. When steering wheel operations are
heavier than usual, grip the steering wheel firmly and operate it using more force than
usual. ■
If the tire pressure warning light comes on
Be sure to observe the following precaution s. Failure to do so could cause a 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 pressure
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 a tire is flat, change it
with 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.

702 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85U■
“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
shown on the multi-information display
Stop the vehicle in a safe place and tu rn off the air conditioning system, and
then stop the hybrid system.
If you see steam: Carefully lift the hood after the steam subsides.
If you do not see steam: Carefully lift the hood.
After the hybrid system has
cooled down sufficiently, inspect
the hoses and radiator core (radi-
ator) for any leaks.
Radiator
Cooling fans If a large amount of coolant leaks,
immediately contact your Lexus
dealer.
The coolant level is satisfactory if
it is between the “FULL” and
“LOW” lines on the reservoir.
Reservoir
“FULL” line
“LOW” line
Radiator capIf your vehicle overheats The following may indicate that your vehicle is overheating. ●
The needle of the engine coolant temperature gauge ( → P. 96) enters the
red zone, or a loss of hybrid system power is experienced. (For example, the
vehicle speed does not increase.) ●
“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” or
“Hybrid System Overheated Reduced Output Power” is shown on the
multi-information display. ●
Steam comes out from under the hood.
Correction procedures 1
2
3
1
2
4
1
2
3
4

7038-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85UAdd coolant if necessary. Water can be used in an emergency
if coolant is unavailable.
Start the hybrid system and turn the air conditioning system on to check
that the radiator cooling fans operate and to check for coolant leaks from
the radiator or hoses. The fans operate when the air conditioning system is turned on immediately after a
cold start. Confirm that the fans are operating by checking the fan sound and air
flow. If it is difficult to check these, tu rn the air conditioning system on and off
repeatedly. (The fans may not operate in freezing temperatures.)
If the fans are not operating:
Stop the hybrid system immediately and contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer.
Check if “Engine Coolant Temp High Stop in a Safe Place See Owner’s
Manual” is shown on the multi-information display.
If the message does not disappear:
Stop the hybrid system and contact your Lexus dealer.
If the message is not displayed:
Have the vehicle inspected at the nearest Lexus dealer. 5
6
7
8

730 9-1. Specifications
RX450h_RX450hL _U_OM48F85UGlossary of tire terminology Tire related term Meaning
Cold tire inflation pressure Tire pressure when the vehicle has been parked for
three hours or more, or has no t been driven more than 1
mile or 1.5 km un der that condition
Maximum inflation pres-
sure The maximum cold inflated pr essure to which a tire may
be inflated, shown on the sidewall of the tire
Recommended inflation
pressure Cold tire inflation pressure recommended by a manu-
facturer
Accessory weight The combined weight (in exce ss of those standard items
which may be replaced) of hybrid transmission, power
steering, power brakes, power windows, power seats,
radio and heater, to the extent that these items are avail-
able as factory-installed eq uipment (whether installed
or not)
Curb weight The weight of a motor vehicle with standard equipment,
including the maximum capacity of fuel, oil and coolant,
and if so equipped, air co nditioning and additional
weight optional engine
Maximum loaded vehicle
weight The sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity weight
(d) Production options weight
Normal occupant weight 150 lb. (68 kg) times the numb er of occupants specified
in the second column of Table 1
* that follows
Occupant distribution Distribution of occupants in a vehicle as specified in the
third column of Table 1
* below