ECU LEXUS RX450H 2019 Workshop Manual

2184-1. Before driving
RX450h_RX450hL_U
WARNING
Observe the following precautions.
Failure to do so may result in death or serious injury.
■When taking a nap in the vehicle
Always turn the hybrid system off. Otherwise, if you accidentally move the shift lever or
depress the accelerator pedal, this could cause an accident or fire due to hybrid system
overheating. Additionally, if the vehicle is parked in a poorly ventilated area, exhaust
gases may collect and enter the vehicle, lead ing to death or a serious health hazard.
■When braking
●When the brakes are wet, drive more cautiously.
Braking distance increases when the brakes are wet, and this may cause one side of
the vehicle to brake differently than the other side. Also, the parking brake may not
securely hold the vehicle.
●If the electronically controlled brake function does not operate, do not follow other
vehicles closely and avoid hills or sharp turns that require braking.
In this case, braking is still possible, bu t the brake pedal should be depressed more
firmly than usual. Also, the braking distan ce will increase. Have your brakes fixed
immediately.
●The brake system consists of 2 or more indi vidual hydraulic systems; if one of the sys-
tems fails, the other(s) will still operate. In this case, the brake pedal should be
depressed more firmly than usual and the braking distance will increase. Have your
brakes fixed immediately.
■If the vehicle becomes stuck
Do not spin the wheels excessive ly when any of the tires is up in the air, or the vehicle is
stuck in sand, mud, etc. This may damage the driveline components or propel the vehi-
cle forward or backward, causing an accident.

2224-1. Before driving
RX450h_RX450hL_U
WARNING
■Storage precautions
Observe the following precautions.
Failure to do so may prevent the pedals from being depressed properly, may block the
driver’s vision, or may result in items hittin g the driver or passengers, possibly causing
an accident.
●Stow cargo and luggage in the luggage compartment whenever possible.
●Do not stack cargo and luggage in the luggage compartment higher than the seat-
backs.
●When you fold down the rear seats, long items should not be placed directly behind
the front seats.
●Never allow anyone to ride in the luggage compartment. It is not designed for pas-
sengers. They should ride in their seats with their seat belts properly fastened.
●Do not place cargo or luggage in or on the following locations.
• At the feet of the driver
• On the front passenger or re ar seats (when stacking items)
•On the luggage cover
• On the instrument panel
•On the dashboard
●Secure all items in the occupant compartment.
■Capacity and distribution
●Do not exceed the maximum axle weight rating or the total vehicle weight rating.
●Even if the total load of occupant’s weight and the cargo load is less than the total load
capacity, do not apply the load unevenly. Improper loading may cause deterioration
of steering or braking control whic h may cause death or serious injury.
■Roof luggage carrier precautions
Observe the following precautions:
●Place the cargo so that its weight is distributed evenly between the front and rear
axles.
●If loading long or wide cargo, never exceed the vehicle overall length or width.
( P. 710)
●Before driving, make sure the cargo is secu rely fastened on the roof luggage carrier.
●Loading cargo on the roof luggage carrier will make the center of gravity of the vehi-
cle higher. Avoid high speeds, sudden star ts, sharp turns, sudden braking or abrupt
maneuvers, otherwise it may re sult in loss of control or vehicle rollover due to failure
to operate this vehicle correctly and result in death or serious injury.
●If driving for a long distance, on rough road s, or at high speeds, stop the vehicle now
and then during the trip to make sure the cargo remains in its place.
●Do not exceed 165 lb. (75 kg) cargo weight on the roof luggage carrier.
NOTICE
■When loading cargo (vehicles with a moon roof or panoramic moon roof)
Be careful not to scratch the surface of the moon roof or panoramic moon roof.

2334-1. Before driving
4
Driving
RX450h_RX450hL_U
■Matching trailer ball height to trailer coupler height
■Before towing
Check that the following conditions are met:
●Ensure that your vehicle’s tires are properly inflated. ( P. 717)
●Trailer tires are inflated according to the trailer manufacturer’s recommendation.
●All trailer lights work as required by law.
●All lights work each time you connect them.
●The trailer ball is set at the proper height for the coupler on the trailer.
●The trailer is level when it is hitched.
Do not drive if the trailer is not level, and check for improper to ngue weight, overload-
ing, worn suspension, or other possible causes.
●The trailer cargo is securely loaded.
●The rear view mirrors conform to all applicable federal, state/provincial or local regula-
tions. If they do not, install rear view mirrors appropriate for towing purposes.
■AVS (adaptive variable suspension system) (if equipped)
The suspension can be switched fo r improvement in driveability. (P. 383)
No matter which class of tow hitch
applies, for a more safe trailer hookup,
the trailer ball setup
must be the proper
height for the coupler on the trailer.
Coupler
Trailer ball
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2364-1. Before driving
RX450h_RX450hL_U
WARNING
■Hitch
Trailer hitch assemblies have different weight capacities established by the hitch manu-
facturer. Even though the vehicle may be phys ically capable of towing a higher weight,
the operator must determine the maximum weight rating of the particular hitch assem-
bly and never exceed the maximum weight rating specified for the trailer-hitch.
Exceeding the maximum weight rating set by the trailer-hitch manufacturer can cause
an accident resulting in death or serious personal injuries.
■When towing a trailer
Lexus recommends trailers with brakes that conform to any applicable federal and
state/provincial regulations.
●If the gross trailer weight exceeds unbraked TWR, trailer brakes are required. Lexus
recommends trailers with brakes that conform to all applicable federal and state/pro-
vincial regulations.
●Never tap into your vehicle’s hydraulic system, as this will lower the vehicle’s braking
effectiveness.
●Never tow a trailer without using a safety chain securely attached to both the trailer
and the vehicle. If damage occurs to the co upling unit or hitch ball, there is danger of
the trailer wandering into another lane.
NOTICE
■When installing a trailer hitch
Use only the position recommended by your Lexus dealer. Do not install the trailer
hitch on the bumper; this may cause body damage.
■Do not directly splice trailer lights
Do not directly splic e trailer lights. Directly splicin g trailer lights may damage your
vehicle’s electrical system and cause a malfunction.

2594-3. Operating the lights and wipers
4
Driving
RX450h_RX450hL_U
With the headlights on, push the
lever away from you to turn on the
high beams.
Pull the lever toward you to the center
position to turn the high beams off.
Pull the lever toward you and release
it to flash the high beams once.
You can flash the high beams with the
headlights on or off.
AFS (Adaptive Front-lighting System) secures excellent visibility at intersections
and on curves by automatically adjusting the direction of the light axis of the
headlights according to vehicle speed and the degree of the tire’s angle as con-
trolled by steering input.
AFS operates at speeds of 6 mph (10 km/h) or higher.
●When the steering wheel or turn signal lever is operated while the headlights
are on (low beam), a cornering light w ill turn on and light up the direction of
movement of the vehicle. The cornerin g lights are designed to ensure excel-
lent visibility when making a turn at an intersection.
However, when vehicle speed is approximately 22 mph (35 km/h) or higher, the cor-
nering lights will not turn on.
●When the shift lever is in R while the headlights are on (low beam), both cor-
nering lights will turn on. This is desi gned to enhance visibility when parking.
Turning on the high beam headlights
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AFS (Adaptive Front-lighting System) (if equipped)
Cornering lights (if equipped)

2664-3. Operating the lights and wipers
RX450h_RX450hL_U
(U.S.A.) or (Canada)
Turns the fog lights off
Turns the fog lights on
■Fog lights can be used when
The headlights are on in low beam.
Fog light switch
The fog lights secure excellent visibility in difficult driving conditions, such as
in rain and fog.
Operating instructions
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2754-4. Refueling
4
Driving
RX450h_RX450hL_U
WARNING
■When refueling the vehicle
Observe the following precautions while refueling the vehicle. Failure to do so may
result in death or serious injury.
●After exiting the vehicle and before opening the fuel door, touch an unpainted metal
surface to discharge any static electricity. It is important to discharge static electricity
before refueling because sparks resulting fr om static electricity can cause fuel vapors
to ignite while refueling.
●Always hold the grips on the fuel tank cap and turn it slowly to remove it.
A whooshing sound may be heard when the fu el tank cap is loosened. Wait until the
sound cannot be heard before fully removing the cap. In hot weather, pressurized fuel
may spray out of the filler neck and cause injury.
●Do not allow anyone that has not discharged static electricity from their body to come
close to an open fuel tank.
●Do not inhale vaporized fuel.
Fuel contains substances th at are harmful if inhaled.
●Do not smoke while refueling the vehicle.
Doing so may cause the fuel to ignite and cause a fire.
●Do not return to the vehicle or touch any pe rson or object that is statically charged.
This may cause static electricity to build up, resulting in a possible ignition hazard.
■When refueling
Observe the following precautions to prevent fuel overflowing from the fuel tank:
●Securely insert the fuel nozzle into the fuel filler neck.
●Stop filling the tank after the fuel nozzle automatically clicks off.
●Do not top off the fuel tank.
NOTICE
■Refueling
●Finish refueling within 30 minutes. If more than 30 minutes passes, the internal valve
closes. In this condition, fuel may overflow during the refueling process. Press the fuel
filler door opener switch again.
●Do not spill fuel during refueling.
Doing so may damage the vehicle, such as causing the emission control system to
operate abnormally or damaging fuel system components or the vehicle’s painted
surface.

2764-4. Refueling
RX450h_RX450hL_U
Press the switch to open the fuel
filler door.
The fuel filler door wi ll open within about
10 seconds of the sw itch being pressed.
Before refueling is possible, a message
will be shown on the multi-information
display in the instrument cluster to indi-
cate the progress of the fuel filler door
opener.
Open the fuel filler door until it is securely locked.
Turn the fuel tank cap slowly and
remove it, then put it into the holder
on the fuel filler door.
Opening the fuel tank cap
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2
3

3264-5. Using the driving support systems
RX450h_RX450hL_U
■Conditions under which the BSM function may not function correctly
●The BSM function may not detect vehicles correctly in the following situations:
• When the sensor is misaligned due to a stro ng impact to the sensor or its surround-
ing area
• When mud, snow, ice, a sticke r, etc. is covering the sensor or surrounding area on
the rear bumper
• When driving on a road surf ace that is wet with standing water during bad weather,
such as heavy rain, snow, or fog
• When multiple vehicles are approaching wi th only a small gap between each vehicle
• When the distance between your vehicle and a following vehicle is short
• When there is a significant difference in speed between your vehicle and the vehicle that enters the detection area
• When the difference in speed between your vehicle and another vehicle is changing
• When a vehicle enters a detection area traveling at about the same speed as your vehicle
• As your vehicle starts from a stop, a vehicle remains in the detection area
• When driving up and down cons ecutive steep inclines, such as hills, dips on the road,
etc.
• When driving on roads with sharp bends, consecutive curves, or uneven surfaces
• When vehicle lanes are wide, or when driving on the edge of a lane, and the vehicle in an adjacent lane is far away from your vehicle
• When towing a trailer (vehicles with towing package)
• When items such as a bicycle carrier are installed on the rear of the vehicle
• When there is a significant difference in height between your vehicle and the vehicle that enters the detection area
• Immediately after the BSM function is turned on
●Instances of the BSM function unnecessarily detecting a vehicle and/or object may
increase in the following situations:
• When the sensor is misaligned due to a stro ng impact to the sensor or its surround-
ing area
• When the distance between your vehicle and a guardrail, wall, etc. that enters the detection area is short
• When driving up and down cons ecutive steep inclines, such as hills, dips on the road,
etc.
• When vehicle lanes are narrow, or when driv ing on the edge of a lane, and a vehicle
traveling in a lane other than the ad jacent lanes enters the detection area
• When driving on roads with sharp bends, consecutive curves, or uneven surfaces
• When the tires are slipping or spinning
• When the distance between your vehicle and a following vehicle is short
• When a bicycle carrier or other accessory is installed to the rear of the vehicle
• When towing a trailer (vehicles with towing package)

4325-4. Using the radio
RX450h_RX450hL_U
■If the satellite radio does not operate normally
If a problem occurs with the XM tuner, a message will appear on the screen. Refer to the
table below to identify the problem, an d take the suggested corrective action.
Contact the XM Listener Care Center at 1-877-447-0011 (U.S.A.) or 1-877-438-9677
(Canada).
SAT Check Antenna
The XM antenna is not connected. Check whether the XM
antenna cable is attached securely.
There is a short-circuit in the antenna or the surrounding
antenna cable. See a Lexus certified dealer.
SAT Ch Unauthorized
You have not subscribed to XM Satellite Radio. The radio is
being updated with the latest encryption code. Contact XM
Satellite Radio for subscripti on information. When a con-
tract is canceled, you can choose “Ch000” and all free-to-
air channels.
The premium channel you selected is not authorized. Wait
for about 2 seconds until the radio returns to the previous
channel or “Ch001”. If it does not change automatically,
select another channel. To listen to the premium channel,
contact XM Satellite Radio.
SAT No SignalThe XM signal is too weak at the current location. Wait until
your vehicle reaches a location with a stronger signal.
SAT LoadingThe unit is acquiring audio or program information. Wait
until the unit has rece ived the information.
SAT Channel Off AirThe channel you selected is not broadcasting any program-
ming. Select another channel.
-----There is no song/program title or artist name/feature asso-
ciated with the channel at that time. No action is required.
SAT Chan Unavailable
The channel you selected is no longer available. Wait for
about 2 seconds until the radio returns to the previous
channel or “Ch001”. If it does not change automatically,
select another channel.