warning light LEXUS GS300H 2019 Repair Manual

427 6-3. Do-it-yourself maintenance
6
Maintenance and care
GS450h_300h_OM_OM30F92E_(EE)
WARNING
■When inspecting or replacing tires
Observe the following precautions to prevent accidents. Failure to do so may cause damage to parts of the drive train as well as dangerous han-
dling characteristics, which may lead to an acc ident resulting in death or serious injury.
●Do not mix tires of different makes, models or tread patterns. Also, do not mix tires of remarkably different treadwear.
●Do not use tire sizes other than those recommended by Lexus.
●Do not mix differently constructed tires (radial, bias-belted or bias-ply tires).
●Do not mix summer, all season and snow tires.
●Do not use tires that have been used on another vehicle.Do not use tires if you do not know how they were used previously.
●Vehicles with compact spare tire: Do not tow if your vehicle has a compact spare tire
installed.
●Vehicles with emergency tire puncture repair kit: Do not tow anything if a tire that has been repaired using the emergency tire punc ture repair kit is installed. The load on
the tire may cause unexpected damage to the tire.
■When initializing the tire pressure warning system (vehicles with the tire pressure warning system)
Do not initialize tire inflation pressure withou t first adjusting the tire inflation pressure to the specified level. Otherwise, the tire pre ssure warning light may not come on even if the tire inflation pressure is low, or it may come on when the tire inflation pressure is
actually normal.
■Caution regarding interference with electronic devices (vehicles with the tire pres- sure warning system featuring a tire inflation pressure display function)
●Users of any electrical medical device other than implantable cardiac pacemakers,cardiac resynchronization therapy-pacemakers or implantable cardioverter defi-
brillators should consult the manufacturer of the device for information about its operation under the influence of radio waves.Radio waves could have unexpected effects on the operation of such medical
devices.
●People with implantable cardiac pacemakers, cardiac resynchronization therapy-pacemak-
ers or implantable cardioverter defibrillators should not come within 450 mm (17.7 in.) ofthe tire pressure warning system initiators.
The radio waves may affect the operation of such devices.

441 6-3. Do-it-yourself maintenance
6
Maintenance and care
GS450h_300h_OM_OM30F92E_(EE)
■After a fuse is replaced
●If the lights do not turn on even after the fuse has been replaced, a bulb may need replacement. ( P. 442)
●If the replaced fuse blows again, have the vehicle inspected by any authorized Lexus
retailer or Lexus authorized repa irer, or any reliable repairer.
■If there is an overload in a circuit
The fuses are designed to blow, protecting the wiring harness from damage.
■When replacing light bulbs
Lexus recommends that you us e genuine Lexus products designed for this vehicle. Because certain bulbs are connected to circuits designed to prevent overload, non-gen-
uine parts or parts not designed for this vehicle may be unusable.
WARNING
■To prevent system breakdowns and vehicle fire
Observe the following precautions. Failure to do so may cause damage to the vehicle, and possibly a fire or injury.
●Never use a fuse of a higher amperage rating than that indicated, or use any otherobject in place of a fuse.
●Always use a genuine Lexus fuse or equivalent.
Never replace a fuse with a wire, even as a temporary fix.
●Do not modify the fuses or fuse boxes.
NOTICE
■Before replacing fuses
Have the cause of electrical overload determined and repaired by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer as soon as possible.

4506-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30F92E_(EE)
WARNING
■Replacing light bulbs
●Turn off the lights. Do not attempt to replace the bulb immediately after turning off the lights.
The bulbs become very hot and may cause burns.
●Do not touch the glass portion of the light bulb with bare hands. When it is unavoid- able to hold the glass portion, use and hold with a clean dry cloth to avoid getting
moisture and oils on the bulb. Also, if the bulb is scratched or dropped, it may blow out or crack.
●Fully install light bulbs and any parts used to secure them. Failure to do so may result
in heat damage, fire, or wate r entering the headlight unit. This may damage the head- lights or cause condensation to build up on the lens.
■To prevent damage or fire
●Make sure bulbs are fully seated and locked.
●Check the wattage of the bulb before installing to prevent heat damage.
NOTICE
■When replacing the outer foot lights
If the front window is stopping you from conducting the replace operation properly, open the window on the side you are working on to allow you enough space to work.
Continuing the operation without giving yourself enough space to work could lead you to scratch the vehicle.

451
7When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
7-1. Essential information
Emergency flashers ..................452
If your vehicle has to be
stopped in an
emergency.................................453
7-2. Steps to take in an
emergency
If your vehicle needs
to be towed................................ 454
If you think something
is wrong....................................... 459
If a warning light turns on
or a warning buzzer
sounds..........................................460
If a warning message
is displayed ................................ 466
If you have a flat tire
(vehicles with spare tire) ......498
If you have a flat tire
(vehicles without spare
tire)................................................509
If the hybrid system
will not start................................ 523
If the parking brake
cannot be released................. 525
If the electronic key does
not operate properly ............. 527
If the 12-volt battery is
discharged .................................530
If your vehicle overheats .........535
If the vehicle becomes
stuck ............................................. 542

4607-2. Steps to take in an emergency
GS450h_300h_OM_OM30F92E_(EE)
If 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 inspected by any authorized Lexus retailer or Lexus autho-
rized repairer, or any reliable repairer.
Warning light and warning buzzer list
Warning lightWarning light/Details/Actions
Brake system warning light (warning buzzer)
•Low brake fluid • Malfunction in the electronically controlled brake system Immediately stop the vehicle in a safe place and contact any
authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer. Continuing to drive the vehicle may be dan-gerous.
(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 any authorized Lexus retailer or Lexus authorized repairer, or any
reliable repairer.
Malfunction indicator lamp Indicates a malfunction in:• The hybrid system;
• The emission control system (if equipped); • The electronic engine control system; • The electronic throttle control system; or
• The electronic hybrid transmission control system (if equipped)  Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer immediately.
SRS warning light
Indicates a malfunction in: • The SRS airbag system; or• The seat belt pretensioner system
 Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer immediately.

4617-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
ABS warning light Indicates a malfunction in:•The ABS; or
• The brake assist system  Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer immediately.
Electric power steering system warning light (warning buzzer)
Indicates a malfunction in the EPS (Electric Power Steering) sys- tem Have the vehicle inspected by any authorized Lexus retailer or
Lexus authorized repairer, or any reliable repairer immediately.
(Flashes) (If equipped)
PCS (Pre-Crash Safety system) warning light
●When the warning light flashes (and a buzzer sounds):
Indicates a malfunction in the PCS (Pre-Crash Safety system)  Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer immedi-
ately.
●When the warning light flashes (and a buzzer does not sound):
Indicates that the PCS (Pre-Crash Safety system) is temporarily unavailable, possibly due to either of the following:• An area around the radar sensor or camera sensor being dirty
or covered with condensation, ice, stickers, etc.  Clear the dirt, condensation, ice, stickers, etc. ( P. 264, 285)
• Radar sensor or camera sensor operational conditions (such as temperature etc.) being not met Driving is possible in this case. The PCS (Pre-Crash Safety
system) will be enabled if the operational conditions (such as temperature etc.) are met again.
●When the warning light is illuminated:Either the VSC (Vehicle Stability Control) system or PCS (Pre-Crash Safety system) is disabled or both are disabled.
 To enable the PCS (Pre-Crash Safety system), enable both the VSC system and PCS (Pre-Crash Safety system). ( P. 281, 327)
Slip indicator
Indicates a malfunction in: • The VSC system;• The TRC system; or
• The hill-start assist control system  Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer immediately.
The light will flash when the VSC, TRC or ABS system is operating.
Warning lightWarning light/Details/Actions

4627-2. Steps to take in an emergency
GS450h_300h_OM_OM30F92E_(EE)
(Flashes) (If equipped)
“AFS OFF” indicatorIndicates a malfunction in the adaptive front-lighting system Have the vehicle inspected by any authorized Lexus retailer or
Lexus authorized repairer, or any reliable repairer immediately.
(Flashes)
Brake hold operated indicator Indicates a malfunction in the brake hold system Have the vehicle inspected by any authorized Lexus retailer or
Lexus authorized repairer, or any reliable repairer immediately.
(Flashes)
Parking brake indicator Indicates a malfunction in the parking brake system Have the vehicle inspected by any authorized Lexus retailer or
Lexus authorized repairer, or any reliable repairer immediately.
Brake system warning light Indicates a malfunction in:• The electronically controlled brake system;
• The regenerative braking system; or • The parking brake system Have the vehicle inspected by any authorized Lexus retailer or
Lexus authorized repairer, or any reliable repairer immediately.
Low fuel level warning light Indicates remaining fuel is approximately 9.9 L (2.6 gal.,2.2 Imp.gal.) or less
 Refuel the vehicle.
Seat belt reminder light (warning buzzer)*
Warns the driver and/or front passenger to fasten their seat belts  Fasten the seat belt. If the front passenger’s seat is occupied, the front passenger’s
seat belt also needs to be fa stened to make the warning light (warning buzzer) off.
Master warning lightA buzzer sounds and the warning light comes on and flashes to
indicate that the master warnin g system has detected a malfunc- tion. P. 466
Warning lightWarning light/Details/Actions

4637-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
*: Driver’s and front passenger’s seat belt buzzer:
The driver’s and front passenger’s seat belt buzzer sounds to alert the driver and front passenger that his or her seat belt is not fastened. The buzzer sounds intermittently for
30 seconds after the vehicle reaches a speed of 20 km/h (12 mph). Then, if the seat belt is still unfastened , the buzzer will sound in a different tone for 90 more seconds.
■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 passen-
ger is not sitting in the seat.
●If a cushion is placed on the seat, the sensor may not detect a passenger, and the warn- ing light may not operate properly.
■If the malfunction indicator lamp comes on while driving
The malfunction indicator lamp will come on if the fuel tank becomes completely empty. If the fuel tank is empty, refuel the vehicle immediately. The malfunction indicator lamp
will go off after several trips.
If the malfunction indicator la mp does not go off, contact any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer as soon as possible.
■Electric power steering system warning light (warning buzzer)
When the 12-volt battery charge becomes insufficient or the voltage temporarily drops, the electric power steering system warning light may come on and the warning buzzer
may sound.
(If equipped)
Tire pressure warning light When the light comes on:Low tire inflation pressure such as
• Natural causes ( P. 464) • Flat tire ( P. 498, 509)  Adjust the tire inflation pressure to the specified level.
The light will turn off after a few minutes. In case the light does not turn off even if the tire inflation pressure is adjusted, have thesystem checked by any authorized Lexus retailer or Lexus
authorized repairer, or any reliable repairer. When the light comes on after blinking for 1 minute:Malfunction in the tire pressure warning system
 Have the system checked by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer.
(If equipped)
LKA warning lightThe warning light comes on and a warning message is displayed to
indicate that the LKA (Lane-Keepin g Assist) system is not available temporarily or has detected a malfunction. P. 478
Warning lightWarning light/Details/Actions

4647-2. Steps to take in an emergency
GS450h_300h_OM_OM30F92E_(EE)
■When the tire pressure warning light comes on (if equipped)
Carry out the following procedure after the tire temperature has lowered sufficiently.
●Check the tire inflation pressure and adjust to the appropriate level.
●If the warning light does not go out even afte r several minutes, check that the tire infla- tion pressure is at the specifie d level and carry out initialization.
The warning light may come on again if the above operations are conducted without first
allowing the tire temperature to lower sufficiently.
■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 caused 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 a spare tire
The compact spare tire is not equipped with a tire pressure warning valve and transmit- ter. If a tire goes flat, the tire pressure warning light will not turn off even though the flattire has been replaced with the spare tire.
■Conditions that the tire pressure warning system may not function properly
 P. 420
■If the tire pressure warning light frequently comes on after blinking for 1 minute
If the tire pressure warning light frequently comes on after blinking for 1 minute when the power switch is turned to ON mode, have it checked by any authorized Lexus retailer orLexus authorized repairer, or any reliable repairer.
■Warning buzzer
In some cases, the buzzer may not be heard because of noisy place or an audio sound.

4657-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
WARNING
■If both the ABS and the brake system warning lights remain on
Stop your vehicle in a safe place immediately and contact any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer. The vehicle will become
extremely unstable during braking, and the ABS system may fail, which could cause an accident resulting in death or serious injury.
■When the electric power steering system warning light comes on
The steering wheel may become extremely heavy. If the steering wheel becomes heavier than us ual when operating, hold firmly and oper- ate using more force than usual.
■If the tire pressure warning light comes on
Be sure to observe the following precautions. Failure to do so could cause a loss of vehicle control and result in death or serious injury.
●Stop your vehicle in a safe place as soon as possible. Adjust the tire inflation pressureimmediately.
●If the tire pressure warning light comes on even after tire inflation pressure adjust-
ment, it is probable that you have a flat tire. Check the tires. If a tire is flat, change it with the spare tire and have the flat tire repaired by the nearest any authorized Lexusretailer or Lexus authorized repa irer, or any reliable repairer.
●Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, you could lose control of the steering wheel or the brakes.
■If a blowout or sudden air leakage should occur
The tire pressure warning syst em may not activate immediately.
NOTICE
■To ensure the tire pressure warning system operates properly
Do not install tires with different specifications or makers, as the tire pressure warning system may not operate properly.