check engine LEXUS RC350 2018 Service Manual

4577-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
7
When trouble arises
■SRS warning light
This warning light system monitors the airbag sensor assembly, front impact sensors, side
impact sensors (door), side impact sensors (front), side im pact sensors (rear), driver’s
seat position sensor, driver’s seat belt buckle switch, front passenger occupant classifica-
tion system, “AIR BAG ON” indicator light, “A IR BAG OFF” indicator light, front passen-
ger’s seat belt buckle switch, seat belt pretensioners, airbags, interconnecting wiring and
power sources. ( P. 41)
■Front passenger detection sensor, seat belt reminder and warning buzzer
If luggage is placed on the front passenger seat, the front passenger detection sensor
may cause the warning light to flash and the warning buzzer to sound even if a passenger
is not sitting in the seat.
■If the malfunction indicator lamp comes on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fu el tank immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The light will go off after several driving trips.
If the light does not go off even after severa l trips, contact your Lexus dealer as soon as
possible.
■Electric power steering system warning light (warning buzzer)
When the battery charge becomes insufficien t or the voltage temporarily drops, the
electric power steering system warning li ght may come on and the warning buzzer may
sound.
■When the tire pressure warning light comes on
Check the tire inflation pressu re and adjust to the appropriate level. Pushing the tire
pressure warning reset switch will not tu rn off the tire pressure warning light.
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such as natural air
leaks and tire inflation pressure changes caus ed by temperature. In this case, adjusting
the tire inflation pressure will turn off the warning light (after a few minutes).
■When a tire is replaced with the spare tire (if equipped)
The spare tire is not equipped with a tire pr essure warning valve and transmitter. If a tire
goes flat, the tire pressure warning light will not turn off even though the flat tire has been
replaced with the spare tire.
■Conditions that the tire pressure wa rning system may not function properly
 P. 417
■If the tire pressure warning light freque ntly comes on after blinking for 1 minute
If the tire pressure warning light frequently comes on after blinking for 1 minute when the
engine switch is turned to IGNITION ON mo de, have it checked by your Lexus dealer.
■Warning buzzer
In some cases, the buzzer may not be heard due to being in a noisy location or audio
sound.

4757-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
7
When trouble arises
Indicates a malfunction in the Brake Override System
A buzzer also sounds.
 Have the vehicle inspecte d by your Lexus dealer
immediately.
Indicates that engine oil level is low
This message may ap pear if the vehicle is stopped on a
slope. Move the vehicle to a level surface and check to
see if the message disappears.
 Check the level of engine oil, and add if necessary.
RC F
Indicates a malfunction in:
• The automatic headlight leveling system; or
• The Automatic High Beam system; or
• The LED headlight system
A buzzer also sounds.
 Have the vehicle inspected by your Lexus dealer.
Warning messageDetails/Actions

4787-2. Steps to take in an emergency
RC350_RC300 AWD_RC300_RC F_U(OM24748U)
Indicates a malfunction in the tire pressure warning sys-
tem
Stop the vehicle in a safe place and turn the engine
switch off then on again.
If the tire pressure warn ing indicator flashes for 1
minute then illuminates, ther e is a malfunction in the
system. Have the vehicle inspected at your Lexus
dealer.
Indicates that the tire position information cannot be rec-
ognized
 Drive for a short while an d check if the display
updates.
If the radio wave conditions improve, the display
may return to normal. If th e tire pressure is still not
displayed after driving for several minutes, stop the
vehicle in a safe place, turn the engine switch off
then on again, and start driving.
If the tire pressure is st ill not displayed even after
repeating this process seve ral times, have the vehi-
cle inspected at your Lexus dealer.
(If equipped)
Indicates a malfunction in the DRS (Dynamic Rear Steer-
ing) system
A buzzer also sounds.
 Have the vehicle inspected by your Lexus dealer.
(If equipped)
Indicates a malfunction in the active rear wing
Have the vehicle inspected by your Lexus dealer.
Indicates that the washer fluid level is low
Add washer fluid.
Warning messageDetails/Actions

4797-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
7
When trouble arises
Indicates that remaining fuel is approximately 2.6 gal.
(10 L, 2.2 Imp. gal.) or less
Refuel the vehicle.
Indicates that the outside temperature is approximately
37 F (3 C) or lower
A buzzer also sounds.
 Drive carefully, as the road may be icy.
RC350/RC300
Indicates that the TRAC (Traction Control) system has
been deactivated
Turn the TRAC on. ( P. 314)
(If equipped)
Indicates that the engine oil is scheduled to be changed.
(The indicator will not work properly unless the message
has been reset.)
 Check the engine oil, and change if necessary.
After changing the engine oil, the message should
be reset.
Indicates that all maintenance according to the driven
distance on the maintenance schedule
* should be per-
formed soon.
 Comes on approximately 4500 miles (7200 km)
after the message has been reset.
If necessary, perform maintenance. Please reset
the message after the maintenance is performed.
( P. 385)
Warning messageDetails/Actions

4807-2. Steps to take in an emergency
RC350_RC300 AWD_RC300_RC F_U(OM24748U)
(If equipped)
Indicates that the engine oil should be changed. (After
the engine oil is changed and the message has been
reset.)
Check and change the engine oil, and oil filter by
your Lexus dealer. After chan ging the engine oil, the
message should be reset. ( P. 403)
Indicates that all maintenanc e is required to correspond
to the driven distance on the maintenance schedule
*.
 Comes on approximately 5000 miles (8000 km)
after the message has been reset. (The indicator will
not work properly unless the message has been
reset.)
Perform the necessary maintenance. Please reset
the message after the maintenance is performed.
( P. 385)
Indicates that the Automatic High Beam switch is
pressed while the headlights are in low beam.
 Turn the high beam on and press the Automatic
High Beam switch again.
Indicates that, since the VSC (Vehicle Stability Control)
system was turned off, the pre-collision braking and pre-
collision brake assist are stopped (The pre-collision
warning function will be operational)
 Turn the VSC on. ( P. 315)
Indicates that the PCS (Pre -Collision System) is tempo-
rarily unavailable
 When conditions improve, the system resumes
operation. If this message is displayed continuously,
have the vehicle inspected by your Lexus dealer.
Warning messageDetails/Actions

5037-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
7
When trouble arises
●Stop the vehicle in a safe place on a hard, flat surface.
●Set the parking brake.
●Shift the shift lever to P.
●Stop the engine.
●Turn on the emergency flashers. ( P. 442)
●Check the degree of the tire damage.
A tire should only be repaired with
the emergency tire puncture repair
kit if the damage is caused by a nail
or screw passing through the tire
tread.
• Do not remove the nail or screw from the tire. Removing the
object may widen the opening
and disenable emergency repair
with the kit.
• To avoid sealant leakage, move the vehi cle until the area of the puncture, if
known, is positioned at the top of the tire.
■A flat tire that cannot be repaired with the emergenc y tire puncture repair kit
In the following cases, the tire cannot be repaired with the emergency tire puncture
repair kit. Contact your Lexus dealer.
●When the tire is damaged due to driving without sufficient air pressure
●When the tire lost air pressure due to a crack or damage in the tire sidewall
●When the tire is visibly separated from the wheel
●When the cut or damage to the tread is 0.16 in. (4 mm) long or more
●When the wheel is damaged
●When 2 or more sharp objects, such as nails or screws, have passed through the tread
on a single tire
●When there is more than one hole or cut in the damaged tire
●When the sealant has expired
Before repairing the vehicle

5097-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
7
When trouble arises
Attach the 2 stickers as shown.
Remove any dirt and moisture from the
wheel before attaching the label. If it is
impossible to attach the label, make sure
to tell your Lexus dealer when you have
them repair and replace the tire that
sealant is injected.
Check the specified tire inflation
pressure.
Tire inflation pressure is specified on the
label as shown. ( P. 548)
Start the engine. ( P. 207)
To inject the sealant and inflate the
tire, turn the compressor switch on.
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5207-2. Steps to take in an emergency
RC350_RC300 AWD_RC300_RC F_U(OM24748U)
Ensure that the shift lever is in P and depress the brake pedal.
Touch the Lexus emblem side of the
electronic key to the engine switch.
When the electronic key is detected, a
buzzer sounds and the engine switch
will turn to IGNITION ON mode.
When the smart access system with
push-button start is deactivated in cus-
tomization setting, the engine switch will
turn to ACCESSORY mode.
Firmly depress the brake pedal and check that is shown on the multi-
information display.
Press the engine switch.
In the event that the engine still cannot be started, contact your Lexus dealer.
■Stopping the engine
Shift the shift lever to P and press the engine switch as you normally do when stopping
the engine.
■Replacing the key battery
As the above procedure is a temporary measure, it is recommended that the electronic
key battery be replaced immediately when the battery is depleted. ( P. 427)
■Changing engine switch modes
Release the brake pedal and press the engine switch in step above.
The engine does not start and modes will be changed each time the switch is pressed.
(  P. 208)
■When the electronic key does not work properly
●Make sure that the smart access system wi th push-button start has not been deacti-
vated in the customization setting. If it is off, turn the function on.
(Customizable features:  P. 569)
●Check if battery-saving mode is set. If it is set, cancel the function. (P. 158)
Starting the engine
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5297-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
7
When trouble arises
Add coolant if necessary.
Water can be used in an emerge ncy if coolant is unavailable.
Start the engine and turn the air conditio ning system on to check that the radi-
ator 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, turn the air conditioning system on and off repeatedly.
(The fan may not operate in freezing temperatures.)
If the fans are not operating:
Stop the engine immediately an d contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer.
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Engine (RC350/RC300 AWD)Engine (RC300)
Engine (RC F)Intercooler (RC300)
6
7

5408-1. Specifications
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
■Oil capacity (Drain and refill [Reference*])
*: The engine oil capacity is a reference quantity to be used when changing the engine
oil. Warm up and turn off the engine, wait more than 5 minutes, and check the oil level
on the dipstick.
Fuel
Fuel typeUnleaded gasoline only
Octane Rating91 (Research Octane Number 96) or higher
Fuel tank capacity
(Reference)17.5 gal. (66.3 L, 14.6 Imp. gal.)
Lubrication system
With filterWithout filter
RC3506.0 qt. (5.7 L, 5.0 Imp. qt.)5.8 qt. (5.5 L, 4.8 Imp. qt.)
RC350 AWD/
RC300 AWD6.8 qt. (6.4 L, 5.6 Imp. qt.)6.3 qt. (6.0 L, 5.3 Imp. qt.)
RC3004.9 qt. (4.6 L, 4.0 Imp. qt.)4.5 qt. (4.3 L, 3.8 Imp. qt.)
RC F9.3 qt. (8.8 L, 7.7 Imp. qt.)8.3 qt. (7.9 L, 7.0 Imp. qt.)