Page 524 of 680

5247-3. Do-it-yourself maintenance
NX300h_OM_USA_OM78082U
NOTICE
■Repairing or replacing tires, wheels, tire pressure warning valves, 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 are 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 se alant is used, contact your Lexus dealer or
other qualified service shop as soon as possible. After use of liquid sealant, make sure
to replace the tire pressure warning valve and transmitter when repairing or replacing
the tire. ( P. 5 1 7 , 5 2 9 )
■Driving on rough roads
Take particular care when driving on roads with loose surfaces or potholes.
These conditions may cause losses in tire inflation pressure, 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.
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5277-3. Do-it-yourself maintenance
7
Maintenance and care
NX300h_OM_USA_OM78082U
■Instructions for checking tire inflation pressure
When checking tire inflation pressure, observe 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 inflation 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.
WA R N I N G
■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 resulting in death or serious injury:
●Excessive wear
●Uneven wear
●Poor handling
●Possibility of blowouts result ing 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 in 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.
Page 530 of 680
5307-3. Do-it-yourself maintenance
NX300h_OM_USA_OM78082U
Air conditioning filter
Turn 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 filter cover.
The air conditioning filter must be changed regularly to maintain air condi-
tioning efficiency.
Removal method
1
2
3
4
Page 531 of 680
5317-3. Do-it-yourself maintenance
7
Maintenance and care
NX300h_OM_USA_OM78082U
Remove the air conditioning filter
and replace it with a new one.
The “UP” marks shown on the filter
should be pointing up.
■Checking interval
Inspect and replace the air conditioning filt er according to the maintenance schedule. In
dusty areas or areas with heavy traffic flow, 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.
5
NOTICE
■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.
Page 569 of 680

5698-2. Steps to take in an emergency
8
When trouble arises
NX300h_OM_USA_OM78082U
■When the tire pressure warning light comes on
Inspect the appearance of the tire to check that the tire is not punctured.
If the tire is punctured: P. 5 7 5
If the tire is not punctured:
Carry out the following procedure after the tire temperature has lowered sufficiently.
●Check the tire inflation pressure and adjust to the appropriate level.
●If the warning light does not go out even after several minutes, check that the tire infla-
tion pressure is at the specified level and carry out initialization. ( P. 5 1 8 )
The warning light may come on again if the above operations are conducted without first
allowing the tire temperature to lower sufficiently.
■The tire pressure warning light may 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 caused by temperature. In this case, adjusting
the tire inflation pressure will turn off the warning light (after a few minutes).
■When a tire is replaced with a spare tire
Vehicles with a compact spare tire: The comp act spare tire is not equipped with a tire
pressure warning valve and transmitter. If a tire goes flat, the tire pressure warning light
will not turn off even though the flat tire ha s been replaced with the spare tire. Replace
the spare tire with the repaired tire and adjust the tire inflation pressure. The tire pressure
warning light will go off after a few minutes.
Vehicles with a full-size spare tire: The spare tire is also equipped with a tire pressure
warning valve and transmitter. The tire pressure warning light will turn on if the tire infla-
tion pressure of the spare tire is low. 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
warning light will go off after a few minutes.
■Conditions that the tire pressure warning system may not function properly
P. 5 2 1
■If the tire pressure warning light frequently comes on after blinking for 1 minute
If the tire pressure warning light frequently comes on after blinking for 1 minute when the
power switch is turned to ON mode, ha ve it checked by your Lexus dealer.
■Warning buzzer
In some cases, the buzzer may not be heard due to being in a noisy location or audio
sound.
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5738-2. Steps to take in an emergency
8
When trouble arises
NX300h_OM_USA_OM78082U
*: A buzzer sounds the first time a message is shown on the multi-information display.
■System warning lights
The master warning light does not come on or flash in the following cases. Instead, a sep-
arate system warning light will come on along with a message shown on the multi-infor-
mation display.
●Malfunction of the ABS
The ABS warning light comes on. ( P. 566)
●Malfunction of th e charging system
The charging system warning light comes on. ( P. 565)
■If “Hybrid System Overheated Reduced Output Power” is shown
This message may be displayed when driv ing under severe operating conditions.
(For example, when drivin g up a long steep hill.)
Handling method: P. 5 9 9
■If “Cooling Performance of The Hybrid Battery Is Low” is shown
The filter may be clogged, or the air intake vents or ducts may be blocked. Have the vehi-
cle inspected by your Lexus dealer.
■If “Hybrid Battery Low Shift Out of N to Recharge” is shown
Message is displayed when the remaining charge for the hybrid battery (traction battery)
is low.
As the hybrid battery (traction battery) cannot be charged when the shift lever is in N,
when stopped for long periods of time shift the shift lever to P.
■If “Hybrid Battery Low Hybrid System St opped Shift to P and Restart” is shown
Message is displayed when the remaining charge for the hybrid battery (traction battery)
is low, because vehicle has been sh ifted N for a long period of time.
When operating the vehicle, restart the hybrid system.
■If “Shift to P Before Exiting Vehicle” is shown
Message is displayed when the driver’s door is opened without turning the power switch
to OFF with the shift lever in any position other than P.
Shift the shift lever to P.
■If “Shift Is in N Release Accele rator Before Shifting” is shown
Message is displayed when the accelerator pe dal has been depressed and the shift lever
is in N. Release the accelerator peda l and shift the shift lever to D or R.
Comes
onDoes not sound
Indicates a condition, such as malfunc-
tion of electrical components, their
condition, or indicates the need for
maintenance
FlashesDoes not sound
Indicates a situation, such as when an
operation has been performed incor-
rectly, or indicates how to perform an
operation correctly
System
warning
lightWa r n i n g b u z z e r*Wa r n i n g
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599
8
When trouble arises
8-2. Steps to take in an emergency
NX300h_OM_USA_OM78082U
If your vehicle overheats
■“Engine Coolant Temp High” 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 (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact your Lexus
dealer.
The following may indicate that your vehicle is overheating.
●The needle of the engine coolant temperature gauge ( P. 97) enters the
red zone, or a loss of hybrid system po wer is experienced. (For example, the
vehicle speed does not increase.)
●“Engine Coolant Temp High” or “Hybrid System Overheated” is shown on
the multi-information display.
●Steam comes out from under the hood.
Correction procedures
1
2
3
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2
Page 600 of 680

6008-2. Steps to take in an emergency
NX300h_OM_USA_OM78082U
The coolant level is satisfactory if it is between the “FULL” and “LOW” lines
on the reservoir.Reservoir
“FULL” line
“LOW” line
Add 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 op erating 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” 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.
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