Page 511 of 620

5117-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
■Warning message in radar cruise mode (if equipped)
In the following cases, the warning message may not be displayed even if vehicle-to-vehi-
cle distance decreases:
●When your vehicle and the vehicle ahead are traveling at the same speed or the vehicle
ahead is traveling more quickly than your vehicle
●When the vehicle ahead is traveling at a very low speed
●Immediately after cruise control speed is set
●At the instant the accelerator pedal is depressed
■Open door warning message
The open door warning message continues to display until a door or the trunk is fully
closed, even if the power switch is turned off. However, approximately 20 minutes after a
door or the trunk is not fully closed, the 12-volt battery-saving function operates and the
display turns off even though a door or the trunk is not fully closed.
■Warning buzzer
In some cases, the buzzer may not be heard because of noisy place or an audio sound.
Page 515 of 620

5157-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
Power was turned off due to the
automatic power off function.
→Next time when starting the
hybrid system, operate the
hybrid system for approximately
5 minutes to recharge the 12-
volt battery.
OnceThe electronic key has a low battery.
→Replace the electronic key bat-
tery. ( →P. 4 5 1 )
Once
The driver’s door was opened and
closed with the power switch turned
off and then the power switch was
put in ACCESSORY mode twice
without the hybrid system being
started.
→ Press the power switch while
depressing the brake pedal.
During an hybrid system starting
procedure in the event that the elec-
tronic key was not functioning prop-
erly ( →P. 5 4 9 ) , t h e p o w e r s w i t c h
was touched with the electronic key.
→ Press the power switch within 10
seconds of the buzzer sounding.
Once
The steering lock could not be
released within 3 seconds of the
power switch being pressed.
→Press the power switch while
depressing the brake pedal and
moving the steering wheel left
and right.
Interior
buzzerExteriorbuzzerWarning messageDetails/Actions
(Flashes)
Page 543 of 620

543
7
7-2. Steps to take in an emergency
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
If the hybrid system will not start
One of the following may be the cause of the problem:
●The electronic key may not be functioning properly. (
→P. 549)
●There may not be sufficient fuel in the vehicle’s tank.
Refuel the vehicle.
●There may be a malfunction in the immobilizer system. ( →P. 8 4 )
●There may be a malfunction in the steering lock system.
●The hybrid system may be malfunctioning due to an electrical problem such
as electronic key battery depletion or a blown fuse. However, depending on
the type of malfunction, an interim measure is available to start the hybrid sys-
tem. ( →P. 544)
One of the following may be the cause of the problem:
●The 12-volt battery may be discharged. ( →P. 5 5 1 )
●The 12-volt battery terminal connections may be loose or corroded.
(→ P. 4 2 8 )
One of the following may be the cause of the problem:
●The 12-volt battery may be discharged. ( →P. 5 5 1 )
●One or both of the 12-volt battery terminals may be disconnected. ( →P. 4 2 8 )
Contact any authorized Lexus dealer or repairer, or another duly qualified and
equipped professional if the problem cannot be repaired, or if repair procedures are
unknown.
Reasons for the hybrid system not starting vary depending on the situation.
Check the following and perform the appropriate procedure:
The hybrid system will not start even though the correct starting proce-
dure is being followed. ( →P. 217)
The interior lights and headlights are dim, or the horn does not sound or
sounds at a low volume.
The interior lights and he adlights do not turn on, or the horn does not
sound.
Page 546 of 620

5467-2. Steps to take in an emergency
GS450h_300h_OM_OM30F00E_(EE)
If the parking brake cannot be released
●Shift the shift lever to P.
●Turn the power switch off.
●Check that the parking brake indicator is off.
●Chock the tires.
Take out the parking brake release
tool and the screwdriver from the
trunk. ( →P. 5 1 8 , 5 2 9 )
Fit the parking brake release tool into
the screwdriver handle.
Vehicles with spare tire: Take out the spare tire. ( →P. 5 2 0 )
Vehicles without spare tire: Remove the center auxiliary box. ( →P. 5 3 1 )
In the event that the 12-volt battery is discharged or switch operation does not
release the parking brake, the parking brake can be released manually using
the procedure below. This procedure should be performed only if necessary,
such as in an emergency.
If the switch cannot be operated even when the 12-volt battery is normal, the
parking brake system may be malfunct ioning. Have the vehicle inspected by
any authorized Lexus dealer or repairer, or another duly qualified and
equipped profession al immediately.
Before releasing the parking brake manually
Releasing the parking brake manually
1
2
Page 548 of 620
5487-2. Steps to take in an emergency
GS450h_300h_OM_OM30F00E_(EE)
If the electronic key does not operate properly
■Doors
Use the mechanical key ( →P. 1 3 5 )
in order to perform the following
operations:
Locks all the doors
Closes the windows and moon
roof (turn and hold)
*
Unlocks all the doors
Opens the windows and moon
roof (turn and hold)
*
*
: This setting must be customized at any authorized Lexus dealer or repairer, or another duly qualified and equipped professional.
■Tr u n k
Turn the mechanical key clockwise
to open.
If communication between the electronic key and vehicle is interrupted
(→ P. 155) or the electronic key cann ot be used because the battery is
depleted, the smart entry & start system and wireless remote control can-
not be used. In such cases, the d oors and trunk can be opened and the
hybrid system can be started by following the procedure below.
Locking and unlocking the doors, unlocking the trunk and key linked
functions
1
2
3
4
Page 549 of 620

5497-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
Ensure that the shift lever is in P and depress the brake pedal.
Touch the Lexus emblem side of the
electronic key to the power switch.
When the electronic key is detected, a
buzzer sounds and the power switch will
turn to ON mode.
When the smart entry & start system is
deactivated in customization setting, the
power switch will turn to ACCESSORY
mode.
Firmly depress the brake pedal and check that is shown on the multi-
information display.
Press the power switch.
In the event that the hybrid system still cannot be started, contact any authorized
Lexus dealer or repairer, or another duly qualified and equipped professional.
■Stopping the hybrid system
Shift the shift lever to P and press the power sw itch as you normally do when stopping the
hybrid system.
■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. 4 5 1 )
■Alarm (if equipped)
Using the mechanical key to lock the doors will not set the alarm system.
If a door is unlocked using the mechanical key when the alarm system is set, the alarm
may be triggered.
■Changing power switch modes
Release the brake pedal and press the power switch in step above.
The hybrid system does not start and modes will be changed each time the switch is
pressed.( →P. 2 1 8 )
■When the electronic key does not work properly
●Make sure that the smart entry & start syst em has not been deactivated in the customi-
zation setting. If it is off, turn the function on.
(Customizable features: →P. 5 8 1 )
●Check if battery-saving mode is set. If it is set, cancel the function. (→P. 1 5 4 )
Starting the hybrid system
1
2
3
4
3
Page 551 of 620
551
7
7-2. Steps to take in an emergency
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
If the 12-volt battery is discharged
If you have a set of jumper (or booster) cables and a second vehicle with a 12-volt
battery, you can jump start your vehicle by following the steps below.
Confirm that the electronic key is
being carried.
When connecting the jumper (or
booster) cables, depending on the situa-
tion, the alarm may activate and doors
locked. ( →P. 9 2 )
Open the hood ( →P. 4 1 7 ) , r e m o v e
the engine compartment covers
( → P. 421) and open the fuse box
cover.
Remove all of the clips.
Push the tabs on either side to
detach the lock and lift the lid off
while pulling the lock plate.
Open the exclusive jump starting
terminal cover.
The following procedures may be used to start the hybrid system if the 12-volt
battery is discharged.
You can also call any authorized Lexus dealer or repairer, or another duly
qualified and equipped professional.
1
2
1
2
3
Page 553 of 620

5537-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
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 the negative cable to a solid, station-
ary, unpainted metallic point away from the exclusive jump starting terminal
and any moving parts, as shown in the illustration.
Start the engine of the second vehicle. Increase the engine speed slightly and
maintain at that level for approximately 5 minutes to recharge the 12-volt bat-
tery of your vehicle.
Open and close any of the doors of your vehicle with the power switch off.
Maintain the engine speed of the second vehicle and start the hybrid system
of your vehicle by turning the power switch to ON mode.
Make sure the “READY” indicator come s on. If the indicator does not come
on, contact any authorized Lexus dealer or repairer, or another duly qualified
and equipped professional.
Once the hybrid system has started, remove the jumper cables in the exact
reverse order from which they were connected.
Once the hybrid system starts, have the vehicle inspected at any authorized
Lexus dealer or repairer, or another duly qualified and equipped professional as
soon as possible.1
2
3
4
6
7
8
9
10