2015 LEXUS NX300h cooling

508 7-3. Do-it-yourself maintenance
NX300h_U_OM78007U The coolant level is satisfactory if it is between the “FULL” and “LOW” lines on
the reservoir when the hybrid system is cold. ■
Engine coolant reservoir
Reservoir cap
“FULL” line
“LOW” line If the level is on or below the “LOW”
line, add coolant up to the “FULL”
line. (  P. 6 0 0 )
■
Power control unit coolant reservoir
Reservoir cap
“FULL” line
“LOW” line If the level is on or below the “LOW”
line, add coolant up to the “FULL”
line.■
Coolant selection
Only use “Toyota Super Long Life Coolant” or a similar high qu ality ethylene glycol
based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life hybrid
organic acid technology.
U.S.A.:
“Toyota Super Long Life Coolant” is a mixt ure of 50% coolant and 50% deionized water.
(Minimum temperature: -31  F [-35  C])
Canada:
“Toyota Super Long Life Coolant” is a mixt ure of 55% coolant and 45% deionized water.
(Minimum temperature: -44  F [-42  C])
For more details about coolant, contact your Lexus dealer. ■
If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine/p ower control unit coolant reservoir caps,
drain cock and water pump.
If you cannot find a leak, have your Lexus dealer test the cap and check for leaks in the
cooling system.Coolant 1
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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.

5738-2. Steps to take in an emergency
8
When trouble arises
NX300h_U_OM78007U * : 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 al ong 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. 6 0 0■
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) can not 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
on  Does not sound Indicates a condition, such as malfunc-
tion of electrical components, their
condition, or indicates the need for
maintenance
Flashes  Does not sound Indicates a situation, such as when an
operation has been performed incor-
rectly, or indicates how to perform an
operation correctlySystem
warning
light Wa r n i n g b u z z e r
* Wa r n i n g

5998-2. Steps to take in an emergency
8
When trouble arises
NX300h_U_OM78007U WA R N I N G ■
12-volt battery precautions
The 12-volt battery contains poisonous and corrosive acidic electrolyte, while related
parts contain lead and lead compounds. Ob serve the following precautions when han-
dling the 12-volt battery: ●
When working with the 12-volt battery, alwa ys wear safety glasses and take care not
to allow any battery fluids (acid) to come in to contact with skin, clothing or the vehicle
body. ●
Do not lean over the 12-volt battery. ●
In the event that battery fluid comes into contact with the skin or eyes, immediately
wash the affected area with water and seek medical attention.
Place a wet sponge or cloth over the affected area until medical attention can be
received. ●
Always wash your hands after handling the 12-volt battery support, terminals, and
other battery-related parts. ●
Do not allow children near the 12-volt battery. ■
After recharging the 12-volt battery
Have the 12-volt battery inspected at your Lexus dealer as soon as possible.
If the 12-volt battery is deteriorating, continued use may cause the 12-volt battery to
emit a malodorous gas, which may be de trimental to the health of passengers.■
When exchanging the 12-volt battery
After exchanging, securely attach the exha ust hose and exhaust hole plug to the
exhaust hole of the exchanged 12-volt battery. If not properly installed, gases (hydro-
gen) may leak into the vehicle interior, and th ere is the possible danger of the gas ignit-
ing and exploding.
NOTICE ■
When handling jumper cables
When connecting the jumper cables, ensure th at they do not become entangled in the
cooling fans or belt. ■
To prevent damaging the vehicle
The exclusive jump starting terminal is to be used when charging the 12-volt battery
from another vehicle in an emergency. It ca nnot be used to jump start another vehicle.

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
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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
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602 8-2. Steps to take in an emergency
NX300h_U_OM78007U ■
If “Hybrid System Overheated” is shown on the multi-information display
Stop the vehicle in a safe place.
Stop the hybrid system and carefully lift the hood.
After the hybrid system has cooled down, 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 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. 1
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3
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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