engine coolant LEXUS NX300h 2015 User Guide

5097-3. Do-it-yourself maintenance
7
Maintenance and care
NX300h_U_OM78007U Check the radiator and condenser and clear away any foreign objects.
If either of the above parts is extremely dirty or you are not sure of their condi-
tion, have your vehicle inspected by your Lexus dealer. WA R N I N G ■
When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps.
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing serious injuries, such as burns.
NOTICE ■
When adding coolant
Coolant is neither plain water nor straight antifreeze. The correct mixture of water and
antifreeze must be used to provide proper lubrication, corrosion protection and cool-
ing. Be sure to read the antifreeze or coolant label. ■
If you spill coolant
Be sure to wash it off with water to prevent it from damaging parts or paint.
Radiator and condenser WA R N I N G ■
When the hybrid system is hot
Do not touch the radiator or condenser as they may be hot and cause serious injuries,
such as burns. ■
When the electric cooling fans are operating
Do not touch the engine compartment.
With the power switch in ON mode, the electric cooling fans may automatically start to
run if the air conditioning is on and/or the coolant temperature is high. Be sure the
power switch is off when working near the electric cooling fans or radiator grille.

564 8-2. Steps to take in an emergency
NX300h_U_OM78007UIf you think something is wrong ●
Fluid leaks under the vehicle
(Water dripping from the air co nditioning after use is normal.)●
Flat-looking tires or uneven tire wear ●
Engine coolant temperature gauge needle continually points higher than nor-
mal ●
Changes in exhaust sound ●
Excessive tire squeal when cornering ●
Strange noises related to the suspension system ●
Pinging or other noises related to the hybrid system ●
Engine misfire or misses, st umbling 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, spongy f eeling, pedal almost touches the floorIf you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact your Lexus dealer as soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms

565
8
When trouble arises 8-2. Steps to take in an emergency
NX300h_U_OM78007UIf a warning light turns on or a warning buzzer
sounds Calmly perform the following actions if any of the warning lights comes on or
flashes. If a light comes on or flashes, bu t then goes off, this does not necessar-
ily indicate a malfunction in the system. However, if this continues to occur,
have the vehicle inspected by your Lexus dealer.
Warning light and warning buzzer list Warning light Warning light/Details/Actions(U.S.A.)
(Canada)
Brake system warning light
Indicates that:
• The brake fluid level is low; or
• The brake system is malfunctioning
 Immediately stop the vehicle in a safe place and contact your
Lexus dealer. Continuing to drive the vehicle may be dangerous.
* 1
Charging system warning light
Indicates a malfunction in the vehicle’s charging system
 Immediately stop the vehicle in a safe place and contact your
Lexus dealer. Continuing to drive the vehicle may be dangerous.
* 1
Low engine oil pressure warning light (warning buzzer)
Indicates that the engine oil pressure is too low
 Immediately stop the vehicle in a safe place and contact your
Lexus dealer. Continuing to drive the vehicle may be dangerous.
* 1
High coolant temperature warning light (warning buzzer)
Indicates that the engine is overheating
 Immediately stop the vehicle in a safe place. Continuing to drive
the vehicle may be dangerous.
Handling method (  P. 600)
Brake system warning light
Indicates a malfunction in:
• The regenerative braking system;
• The electronically controlled brake system; or
• The electric parking brake
 Have the vehicle inspected by your Lexus dealer immediately. (U.S.A.)
(Canada)
Malfunction indicator lamp
Indicates a malfunction in:
• The hybrid system;
• The electronic engine control system;
• The electronic throttle control system; or
• The emission control system
 Have the vehicle inspected by your Lexus dealer immediately.

574 8-2. Steps to take in an emergency
NX300h_U_OM78007U ■
If “Depress Brake When Vehicle Is Stopped Hybrid System May Overheat” is shown
Message is displayed when the accelerator pedal is depressed to maintain the vehicle
position when stopped on a upward slope, etc.
If this continues, the hybrid system may overheat.
Release the accelerator pedal and depress the brake pedal. ■
If “Oil Maintenance Required Soon” is shown
Indicates that the engine oil is scheduled to be changed. (The indicator will not work
properly unless the oil maintenance data has been reset.)
Check the engine oil, and change if necessar y. After changing the engine oil, the oil
change system should be reset. (  P. 5 0 6 )■
If “Oil Maintenance Required” is shown
Indicates that the engine oil should be changed. (After the engine oil is changed and the
oil maintenance data has been reset.)
Check and change the engine oil, and oil filt er by your Lexus dealer. After changing the
engine oil, the oil change system should be reset. (  P. 5 0 6 )■
If “See Owner’s Manual” is shown ●
If the following messages are shown, following the instru ctions, accordingly.
• “Engine Coolant Temp High” (  P. 6 0 0 )●
If the following messages are sh own, there may be a malfunction.
Immediately have the vehicle inspected by your Lexus dealer.
• “Hybrid System Malfunction”
•“Check Engine”
• “Hybrid Battery System Malfunction”
• “Accelerator System Malfunction”
• “Braking Power Low”
• “Smart Access System Malfunction” ●
If the following messages are sh own, there may be a malfunction.
Immediately stop the vehicle in a safe place and contact your Lexus dealer. Continuing
to drive the vehicle may be dangerous.
•“Low Oil Pressure”
• “Charging System Malfunction” ■
Warning buzzer
 P. 5 6 9
NOTICE ■
“High Power Consumption Partial Limit On AC/Heater Operation” is frequently
shown
There is a possible malfunction relating to the charging system or the 12-volt battery
may be deteriorating. Have the vehicle inspected by your Lexus dealer.

600 8-2. Steps to take in an emergency
NX300h_U_OM78007UIf 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
1
2

6018-2. Steps to take in an emergency
8
When trouble arises
NX300h_U_OM78007U 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. 4
1
2
3
5
6
7
8

6038-2. Steps to take in an emergency
8
When trouble arises
NX300h_U_OM78007U Start the hybrid system and check if “Hybrid System Overheated” 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. WA R N I N G ■
To prevent an accident or injury when in specting under the hood of your vehicle
Observe the following precautions.
Failure to do so may result in serious injury such as burns. ●
If steam is seen coming from under the h ood, do not open the hood until the steam
has subsided. The engine compartment may be very hot. ●
After the hybrid system has been turned off, check that the “READY” indicator are
off.
When the hybrid system is operating, the gasoline engine may au tomatically start, or
the cooling fan may suddenly operate even if the gasoline engine stops. Do not touch
or approach rotating parts such as the fa n, which may lead to fingers or clothing
(especially a tie, a scarf or a muffler) ge tting caught, resulting in serious injury.●
Do not loosen the coolant reservoir cap while the hybrid system and radiator are hot.
High temperature steam or coolant could spray out.
NOTICE ■
When adding engine/power control unit coolant
Add coolant slowly after the hybrid system has cooled down sufficiently. Adding cool
coolant to a hot hybrid system too quickly can cause damage to the hybrid system. ■
To prevent damage to the cooling system
Observe the following precautions: ●
Avoid contaminating the coolant with foreign matter (such as sand or dust etc.). ●
Do not use any coolant additive. 6

6139-1. Specifications
9
Vehicle specifications
NX300h_U_OM78007U * : The coolant capacity is the quantity of reference.
If replacement is necessary, contact your Lexus dealer.Cooling system Capacity
* Gasoline
engine 
Vehicles without towing package
7.7 qt. (7.3 L, 6.4 Imp.qt.) 
Vehicles with towing package
7.1 qt. (6.7 L, 5.9 Imp.qt.)
Po w e r
control unit 3.3 qt. (3.1 L, 2.7 Imp.qt.)
Coolant type Use either of the following:
• “Toyota Super Long Life Coolant”
• Similar high-quality ethylene glycol-based
non-silicate, non-amine, non-nitrite, and non-
borate coolant with long-life hybrid organic
acid technology
Do not use plain water alone.
Ignition system (spark plug) Make DENSO FK16HR-A8
Gap 0.03 in. (0.8 mm)
NOTICE ■
Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.
Electrical system 12-volt battery
Open voltage at 68  F (20  C): 12.6 V or higher: Fully charged
12.2 — 12.4 V: Half charged
12.0 V or lower: Discharged
(Voltage is checked 20 minutes after the hybrid
system and all lights are turned off.)
Charging rates 5 A max.

6279-1. Specifications
9
Vehicle specifications
NX300h_U_OM78007U Glossary 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 not been driven more than 1
mile or 1.5 km un der that condition
Maximum inflation pres-
sure The maximum cold inflated pressure 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 excess of those standard items
which may be replaced) of transmission, power steer-
ing, power brakes, power wi ndows, power seats, radio
and heater, to the extent that these items are available as
factory-installed equipment (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 occupa nts 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

667Alphabetical index
NX300h_U_OM78007U If you have a flat tire ..........................575
If you lose your keys ................ 120, 122
If you think something is
wrong .................................................. 564
If your vehicle becomes
stuck ..................................................... 604
If your vehicle has to
be stopped in an
emergency.........................................557
If your vehicle needs to be
towed................................................... 558
If your vehicle overheats ............... 600
Energy monitor ..........................................111
Engine
Accessory mode................................202
Compartment..................................... 502
Engine switch ........................................ 201
Hood ....................................................... 500
How to start the hybrid
system ................................................... 201
Identification number ........................ 610
If your vehicle has to be
stopped in an emergency ..........557
Ignition switch
(power switch).................................. 201
Overheating ........................................ 600
Power switch......................................... 201 Engine compartment cover............. 503
Engine coolant
Capacity...................................................613
Checking .............................................. 508
Preparing and checking
before winter .................................... 326
Warning light .......................................565
Engine coolant temperature
gauge ......................................................... 97
Engine oil
Capacity.................................................... 611
Checking ...............................................504
Warning light .......................................565
Engine oil maintenance data ........... 506
Engine switch ........................................... 201
EPS (Electronic Power Steering)
Function ..................................................305
Warning light .......................................566
EV indicator ............................................... 79
EV drive mode ...................................... 206
Event data recorder (EDR).....................11