2018 LEXUS RX450h engine

660 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85UIf 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, but then goes off, this does not necessar-
ily indicate a malfunction in the system . However, if this continues to occur,
have the vehicle inspecte d 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.
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. (If equipped)
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. (U.S.A.)
(Canada)
Malfunction indicator lamp
Indicates a malfunction in:
• The hybrid system;
• The electronic engine control system; or
• The electronic throttle control system
→ Have the vehicle inspected by your Lexus dealer immediately.
SRS warning light
Indicates a malfunction in:
• The SRS airbag system;
• The front passenger occupant classification system; or
• The seat belt pretensioner system
→ Have the vehicle inspected by your Lexus dealer immediately.

668 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85U* : A buzzer sounds the first time a message is shown on the multi-information display.
●
If the following messages are shown, 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.
• “Braking Power Low Stop in a Safe Place See Owner’s Manual”
• “Oil Pressure Low Stop in a Safe Place See Owner’s Manual”
• “Charging System Malfunction See Owner’s Manual” ●
If the following messages are shown, 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”
• “Access System with Elec. Key Malfunction See Owner’s Manual” ●
If “Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
displayed, following the instructions, accordingly. ( → P. 702)Flashes ⎯ Sounds Indicates a situation, such as when
damage to the vehicle or danger may
result
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 correctly
If a message instructing to refer to the Owner’s Manual is displayed System
warning
light Warning buzzer
* Warning

670 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85U■
If “Shift Is in N Release Accele rator Before Shifting” is shown
Message is displayed when the accele rator pedal has been depressed and
the shift lever is in N. Release the accelerator pedal and shift the shift lever to
D or R. ■
If “Depress Brake when Vehicle Is Stopped Hybrid System May Overheat”
is shown
Message is displayed when the accelerato r 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 “Power Turned Off to Save Battery” is displayed
This message is displayed when the power was cut off due to the automatic
power off function.
The next time the hybrid system is star ted, increase the engine speed slightly
and maintain it at that speed for appr oximately 5 minutes to recharge the 12-
volt battery. ■
If “A New Key has been Registered Contact Your Dealer for Details” is dis-
played
This message will be displayed each time the driver's door is opened when the
doors are unlocked from the outside fo r approximately one week after a new
electronic key has been registered.
If this message is displayed but you ha ve not had a new electronic key regis-
tered, ask your Lexus dealer to check if an unknown electronic key (other than
those in your possession) has been registered. ■
When “Headlight System Malfunctio n Visit Your Dealer” is displayed
The following systems may be malfunct ioning. Have the vehicle inspected by
your Lexus dealer immediately. ●
The LED headlight system ●
The automatic headlight leveling system ●
Automatic High Beam ●
AFS (Adaptive Front-lighting System) (if equipped)

6718-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85U■
If “Forward Camera System Unavailable” or “Forward Camera System
Unavailable Clean Windshield” is displayed
The following systems may be suspended until the problem shown in the mes-
sage is resolved. ( → P. 296)●
PCS (Pre-Collision System) ●
LKA (Lane-Keeping Assist) ●
Dynamic radar cruise control with full-speed range ●
Automatic High Beam■
If “Oil Maintenance Required Soon” is shown
Indicates that the engine oil is scheduled to be changed.
Check the engine oil, and change if necessary. After changing the engine oil,
the message should be reset. ( → P. 600)■
If “Oil Maintenance Required” is shown
Indicates that the engine oil should be changed.
Check and change the engine oil, and o il filter by your Lexus dealer. After
changing the engine oil, the message should be reset. ( → P. 600)■
If “Maintenance Required Soon” is displayed (U.S.A. only)
Indicates that all maintenance according to the driven distance on the mainte-
nance schedule
* should be performed soon.
Comes on approximately 4500 miles (7200 km) after the message has been
reset.
If necessary, perform maintenance. Plea se reset the message after the main-
tenance is performed. ( → P. 588)
* : Refer to the separate “Scheduled Mainte nance” or “Owner’s Manual Supplement”
for the maintenance interval applicable to your vehicle.

688 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85UWARNING ■
When using the compact spare tire ●
Remember that the compact spare tire provid ed is specifically designed for use with
your vehicle. Do not use your comp act spare tire on another vehicle.●
Do not use more than one comp act spare tire simultaneously.●
Replace the compact spare tire with a standard tire as soon as possible.●
Avoid sudden acceleration, abrupt steering, sudden braking and shifting operations
that cause sudden engine braking. ■
When the compact spare tire is attached
The vehicle speed may not be correctly detected, and the following systems may not
operate correctly:
Also, not only can the following system not be utilized fully, but it may even negatively
affect the drive-train components:
•E-Four ■
Speed limit when using the compact spare tire
Do not drive at speeds in excess of 50 mph (80 km/h) when a compact spare tire is
installed on the vehicle.
The compact spare tire is not designed for driving at high speeds. Failure to observe
this precaution may lead to an accid ent causing death or serious injury.■
After using the tools and jack
Before driving, make sure all the tools and jack are securely in place in their storage
location to reduce the possibilit y of personal injury during a collision or sudden brak-
ing.• ABS & Brake assist
•VSC
•TRAC
•EPS
• Trailer Sway Control
•VDIM
• Adaptive Variable Suspension System
(if equipped)
• Dynamic radar cruise control with full-
speed range
• PCS (Pre-Collision System)
• LKA (Lane-Keeping Assist) • Automatic High Beam
• AFS (Adaptive Front-lighting System)
(if equipped)
• Tire pressure warning system
• Intuitive parking assist (if equipped)
• Intelligent Clearance Sonar (ICS) (if
equipped)
• Lexus parking assist monitor (if
equipped)
• Panoramic view monitor (if equipped)
• BSM (Blind Spot Monitor) (if
equipped)
• Navigation system (if equipped)

696 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85URemove the engine cover.
Connect the jumper cables accordin g to the following procedure:
Connect a positive jumper cable clamp to the exclusive jump starting ter-
minal on your vehicle.
Connect the clamp on the other end of the positive cable to the positive (+)
battery terminal on the second vehicle.
Connect a negative cable clamp to the negative (-) battery terminal on the
second vehicle.
Connect the clamp at the other end of th e negative cable to a solid, station-
ary, unpainted meta llic point away from the excl usive jump starting terminal
and any moving parts, as shown in the illustration. 4
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4

6978-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85UStart the engine of the second vehicle. Increase the engine speed slightly and
maintain at that level for approximatel y 5 minutes to recharge the 12-volt bat-
tery of your vehicle.
Open and close any of the doors of yo ur vehicle with the power switch off.
Maintain the engine speed of the seco nd vehicle and start the hybrid system
of your vehicle by turning th e power switch to ON mode.
Make sure the “READY” indicator comes on. If the indicator light does not
come on, contact your Lexus dealer.
Once the hybrid system has started, remove the jumper cables in the exact
reverse order from which they were connected.
Close the exclusive jump starting termin al cover, and reinstall the fuse box
cover to its original position.
Once the hybrid system starts, have th e vehicle inspected at your Lexus dealer
as soon as possible. ■
Starting the hybrid system when the 12-volt battery is discharged
The hybrid system cannot be started by push-starting. ■
To prevent 12-volt battery discharge ●
Turn off the headlights and the audio system while the hybrid system is off. ●
Turn off any unnecessary electrical componen ts when the vehicle is running at a low
speed for an extended period , such as in heavy traffic.■
When removing the battery terminals
When the battery terminals are removed, the information stored in the ECU is cleared.
Before removing the battery termin als, contact your Lexus dealer.6
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702 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85U■
“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” 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 (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 capIf 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
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