Page 698 of 792

6988-2. Steps to take in an emergency
RX450h_RX450hL_U
■Charging the 12-volt battery
The electricity stored in the 12-volt battery will discharge gradually even when the vehicle
is not in use, due to natural discharge and the draining effects of certain electrical appli-
ances. If the vehicle is left for a long time, the 12-volt battery may discharge, and the
hybrid system may be unable to start. (The 12-volt battery recharges automatically while
the hybrid system is operating.)
■When the 12-volt battery is removed or discharged
●In some cases, it may not be possible to un lock the doors using the smart access system
with push-button start when the 12-volt battery is discharged. Use the wireless remote
control or the mechanical key to lock or unlock the doors.
●The hybrid system may not start on the first attempt after the 12-volt battery has
recharged but will start normally after the second attempt. This is not a malfunction.
●The power switch mode is memorized by the vehicle. When the 12-volt battery is
reconnected, the system will retu rn to the mode it was in before the 12-volt battery was
discharged. Before disconnect ing the 12-volt battery, turn the power switch off.
If you are unsure what mode the power switch was in before the 12-volt battery dis-
charged, be especially careful when reconnecting the 12-volt battery.
●The power back door must be initialized. ( P. 150)
■When replacing the 12-volt battery
●RX450h: Use a Central Degassing type 12 -volt battery (European Regulations).
RX450hL: Use a 12-volt battery designed for this vehicle.
●RX450h: Use a 12-volt battery that the case size is same as the previous one (LN2),
20 hour rate capacity (20HR) is equivalent (60Ah) or greater, and performance rating
(CCA) is equivalent (460A) or greater.
• If the sizes differ, the 12-volt battery cannot be properly secured.
• If the 20 hour rate capacity is low, even if the time period where the vehicle is not used is a short time, the 12-volt battery may discharge and the hybrid system may
not be able to start.
Page 702 of 792

7028-2. Steps to take in an emergency
RX450h_RX450hL_U
■“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
shown on the multi-information displayStop 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 (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 cap
If 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
Page 703 of 792

7038-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL_U
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 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
Page 705 of 792

7058-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL_U
Start the hybrid system and check if “Hybrid System Overheated Reduced
Output Power” 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.
WARNING
■To prevent an accident or injury when inspecting 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 is 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 th e fans, which may lead to fingers or cloth-
ing (especially a tie, a scarf or a muffler) getting caught, resulting in serious injury.
●Do not loosen the radiator cap and the coolant reservoir caps wh ile 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 foreig n matter (such as sand or dust etc.).
●Do not use any coolant additive.
6
Page 706 of 792
7068-2. Steps to take in an emergency
RX450h_RX450hL_U
Stop the hybrid system. Shift the shift lever to P and set the parking brake.
Remove the mud, snow or sand from around the front wheels.
Place wood, stones or some other materi al under the front wheels to help pro-
vide traction.
Restart the hybrid system.
Shift the shift lever to D or R and rele ase the parking brake. Then, while exer-
cising caution, depress the accelerator pedal.
■When it is difficult to free the vehicle
If the vehicle becomes stuck
Carry out the following procedures if the tires spin or the vehicle becomes
stuck in mud, dirt or snow:
Press to turn off TRAC.
1
2
3
4
5
Page 713 of 792
7139-1. Specifications
9
Vehicle specifications
RX450h_RX450hL_U
*: The engine oil capacity is a reference quantity to be used when changing the engineoil. Warm up the engine and turn off the hybrid system, wait more than 5 minutes, and
check the oil level on the dipstick.
Hybrid battery (traction battery)
TypeNickel-Metal hydride battery
Voltage9.6 V/module
Capacity6.5 Ah (3HR)
Quantity30 modules
Overall voltage288 V
Lubrication system
Oil capacity
(Drain and refill — reference
*)
With filterVehicles with towing package
5.8 qt. (5.5 L, 4.8 Imp. qt.)
Vehicles without towing package
5.7 qt. (5.4 L, 4.8 Imp. qt.)
Without filter5.6 qt. (5.3 L, 4.7 Imp. qt.)
Page 715 of 792

7159-1. Specifications
9
Vehicle specifications
RX450h_RX450hL_U
*: The coolant capacity is a reference quantity. If replacement is necessary, contact your Lexus dealer.
Cooling system
Capacity*
Gasoline
engine
RX450h
10.7 qt. (10.1 L, 8.9 Imp. qt.)
RX450hL
13.2 qt. (12.5 L, 11 Imp. qt.)
Power control
unit2.0 qt. (1.9 L, 1.7 Imp. qt.)
Coolant type
Use either of the following: • “Toyota Super Long Life Coolant”
• Similar high-quality ethylene glycol-basednon-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)
MakeDENSO FK20HBR8
Gap0.03 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 68F (20C):
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 rates5 A max.
Page 719 of 792
7199-1. Specifications
9
Vehicle specifications
RX450h_RX450hL_U
Light bulbs
Light bulbsBulb No.WType
Exterior
Front side marker lights*15B
Front turn signal lights*17444NA28/8A
Rear turn signal lights*121A
Back-up lights92116B
Interior
Door courtesy lights*25B
Vanity lights8B
Luggage compartment light5B
A: Wedge base bulbs (amber)B: Wedge base bulbs (clear)
*1: Vehicles with single-beam headlights
*2: Vehicles without door trim ornament lights