2015 LEXUS RX450h cooling

6994-3. Do-it-yourself maintenance
4
Maintenance and care
■ Engine compartment (type C fuse box) 49
BIXENON 10 A50
H-LP RH LO 15 A Right-hand headlight (low beam)51
H-LP LH LO 15 A Left-hand headlight (low beam)52
HORN 10 A Horn53
A/F 20 A Multiport fuel injection system/
sequential multiport fuel injection sys-
tem54
S-HORN 7. 5 A S-HORN
Fuse Ampere Circuit1
ABS MAIN NO. 1 10 A Brake system
2
ABS MAIN
NO. 2 10 A Brake system
3
BATT FAN 15 A Battery cooling fan
4
OIL PMP 10 A Hybrid system
5
A/C W/P 10 A Air conditioning systemFuse Ampere Circuit

5
When trouble arises
7875-2. Steps to take in an emergency
CAUTION●
Always wash your hands after handling the 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, co ntinued use may cause the 12-volt battery to
emit a malodorous gas, which may be de trimental to the health of passengers.■
When replacing the 12-volt battery
 P. 6 6 9
NOTICE■
When handling jumper cables
When connecting the jumper cables, ensure that they do not become entangled in
the cooling fans or belt.■
Avoiding accidental short-circuits
When connecting jumper cables, observe the following precautions: ●
Make sure each jumper cable is connected to the correct terminal.●
Do not allow the ends of the jumper cable used for the “+” terminals to come into
contact with any other parts or metal surfaces in the area, such as brackets or
unpainted metal.●
Do not allow the “+” and “-” terminals of the jumper cables to come into contact
with each other.■
Exclusive jump starting terminal precaution
The exclusive jump starting terminal is to be used when charging the 12-volt battery
from another vehicle in an emergency. It cannot be used to jump start another vehi-
cle.

7885-2. Steps to take in an emergency
If your vehicle overheats
Correction procedures
■ If “ENGINE OVERHEAT” is shown on the multi-information display
Stop the vehicle in a safe place and turn 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.
● “ENGINE OVERHEAT” is shown on the multi-information display:
The engine may be overheating.
● “HYBRID SYSTEM OVERHEAT” is sh own on the multi-information
display:
A hybrid system component such as the power control unit or an
electric motor (traction motor) may be overheating.
● Steam comes out from under the hood. STEP 1
STEP 2
STEP 3

5
When trouble arises
7895-2. Steps to take in an emergency
The coolant level is satisfactory if it
is between the “FULL” and “LOW”
lines on the reservoir.
Reservoir
“FULL” line
“LOW” line
Radiator cap
Add coolant if necessary. (
 P. 6 5 5 )
Water can be used in an emer-
gency 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 immedi-
ately after a cold start. Confirm that the fans are operating by checking
the fan sound and air flow. If it is diff icult to check these, turn the air con-
ditioning system on and off repeatedly.
(The fans may not operate in freezing temperatures.)STEP 4
STEP 5
STEP 6

7905-2. Steps to take in an emergency
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.
■ If “HYBRID SYSTEM OVERHEAT” is shown on the multi-informa-
tion display
Stop the vehicle in a safe place. Ensure that the opening for the oil
cooler is not blocked by dirt or any
other foreign substance. If the
opening is not blocked or if the
message does not disappear after
some time the opening has been
cleaned, proceed to STEP 2.
Stop the hybrid system and carefully lift the hood.
After the hybrid system has cooled
down, inspect the hoses and radia-
tor 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” lineSTEP 7
STEP 1
STEP 2
STEP 3
STEP 4

5
When trouble arises
7915-2. Steps to take in an emergency
Add coolant if necessary. Water can be used in an emer-
gency if coolant is unavailable.
Start the hybrid system and check for the multi-information dis-
play.
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.STEP 5
CAUTION■
To prevent an accident or injury when in specting under the hood of your vehicle●
If steam is seen coming from under the hood, do not open the hood until the
steam has subsided. The engine compartm ent may be very hot, causing serious
injuries such as burns.●
After the hybrid system has been turned off, check that the indicator on the
“POWER” switch and the “READY” indicator are off.
When the hybrid system is operating, the gasoline engine may automatically
start, or the cooling fans may suddenly operate even if the gasoline engine stops.
Do not touch or approach rotating parts such as the fans, which may lead to fin-
gers or clothing (especially a tie, a scarf or a muffler) getting caught, resulting in
serious injury.●
Do not loosen the radiator cap while the hybrid system and radiator are hot.
Serious injuries, such as burns, may re sult from hot coolant and steam released
under pressure. STEP 6

7925-2. Steps to take in an emergency
NOTICE■
When adding engine/power control unit coolant
Wait until the hybrid system has cooled down before adding engine/power control
unit coolant.
When adding coolant, do so slowly. 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 foreig n matter (such as sand or dust etc.).●
Do not use any coolant additives.

8046-1. Specifications
Cooling system
* : With towing package
Ignition systemCapacity
Gasoline engine
Power control unit 12.0 qt. (11.4 L, 10.0 Imp. qt.)
12.4 qt. (11.7 L, 10.3 Imp. qt.)*
1.9 qt. (1.8 L, 1.6 Imp. qt.)
Coolant type Use either of the following:
• “Toyota Super Long Life Coolant”
• Similar high-quality ethylene glycol-based non-sili-
cate, non-amine, non-nitrite, and non-borate cool-
ant with long-life hybrid organic acid technology
Do not use plain water alone.
Spark plug
Make
Gap DENSO FK20HR11
0.043 in. (1.1 mm)
NOTICE■
Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.