Page 533 of 676
5336-3. Do-it-yourself maintenance
6
Maintenance and care
LS600h/LS600hL_EE(OM50G20E)
Remove the battery cover bolts
and remove the battery cover.
Remove the depleted battery.
Insert a new battery with the “+” termi-
nal facing up.
■Use a CR1632 lithium battery
●Batteries can be purchased at any authorized Lexus dealer or repairer, or another
duly qualified and equipped professional, local electrical appliance shops or cam-
era stores.
●Replace only with the same or equivalent type recommended by the manufacturer.
●Dispose of used batteries according to local laws.
■When the card key battery needs to be replaced (if equipped)
The battery for the card key is available only at Lexus dealers. Your Lexus dealer can
replace the battery for you.
■If the electronic key battery is depleted
The following symptoms may occur:
●The smart entry & start system and wireless remote control will not function prop-
erly.
●The operational range will be reduced.
3
4
Page 545 of 676

545
7When trouble arises
LS600h/LS600hL_EE(OM50G20E)
7-1. Essential information
Emergency flashers ..................546
If your vehicle has
to be stopped
in an emergency ...................... 547
7-2. Steps to take
in an emergency
If your vehicle needs
to be towed ............................... 548
If you think something
is wrong .......................................554
If a warning light turns
on or a warning buzzer
sounds......................................... 555
If a warning message
is displayed.................................563
If you have a flat tire
(vehicles with
a spare tire)................................ 567
If you have a flat tire
(vehicles without
a spare tire)................................ 578
If the hybrid system
will not start................................ 597
If the parking brake
cannot be released................. 599
If the electronic key does
not operate properly .............603
If the 12-volt battery
is discharged............................. 607
If your vehicle overheats ............ 611
If the vehicle becomes
stuck ...............................................616
Page 597 of 676

5977-2. Steps to take in an emergency
7
When trouble arises
LS600h/LS600hL_EE(OM50G20E)
One of the following may be the cause of the problem:
●The electronic key may not be functioning properly. (P. 605)
●There may not be sufficient fuel in the vehicle’s tank.
Refuel the vehicle.
●There may be a malfunction in the immobilizer system. ( P. 96)
●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 system. ( P. 598)
One of the following may be the cause of the problem:
●The 12-volt battery may be discharged. ( P. 607)
●The 12-volt battery terminal connections may be loose or corroded.
If the hybrid system will not start
Reasons for the hybrid system not starting vary depending on the situa-
tion. Check the following and perf orm the appropriate procedure:
The hybrid system will not start even though the correct starting
procedure is being followed. ( P. 247)
The interior lights and headlights are dim, or the horn does not
sound or sounds at a low volume.
Page 603 of 676
6037-2. Steps to take in an emergency
7
When trouble arises
LS600h/LS600hL_EE(OM50G20E)
Use the mechanical key built in to the electronic keys to operate the
doors. ( P. 141)
Vehicles with an alarm: An alarm will sound if the alarm is set when the trunk or
doors are unlocked. ( P. 103)
■Doors
Remove the cover on the
driver’s door handle.
If the electronic key does not operate properly
If communication between the electronic key and vehicle is inter-
rupted ( P. 159) or the electronic key cannot be used because the
battery is depleted, the smart entry & start system and wireless remote
control cannot be used. In such cases, the doors and trunk can be
opened and the hybrid system can be started by following the proce-
dure below.
Locking and unlocking the doors, unlocking the trunk and key
linked functions
1
Page 605 of 676

6057-2. Steps to take in an emergency
7
When trouble arises
LS600h/LS600hL_EE(OM50G20E)
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.
If any of the doors is opened or closed
after the key was touched to the
switch to start the vehicle, an alarm
will sound to indicate that the start
function cannot detect the key.
Press the power switch within 10 seconds of the buzzer sounding,
keeping the brake pedal depressed.
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 switch as you normally do when stop-
ping the hybrid system.
■Replacing the key battery
As the above procedure is a temporary measure, it is recommended that the elec-
tronic key battery be replaced immediately when the battery is depleted. ( P. 532)
■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
Within 10 seconds of the buzzer sounding, release the brake pedal and press the
power switch.
The hybrid system does not start and modes will be changed each time the switch is
pressed. ( P. 248)
Starting the hybrid system
1
2
3
Page 607 of 676
6077-2. Steps to take in an emergency
7
When trouble arises
LS600h/LS600hL_EE(OM50G20E)
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 sit-
uation, the alarm may activate and
doors locked. (P. 105)
Open the trunk lid and remove the 12-volt battery cover. ( P. 502)
In the event that the trunk opener cannot be used, use the mechanical key to open
the trunk. ( P. 603)
If the 12-volt battery is discharged
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
Page 609 of 676

6097-2. Steps to take in an emergency
7
When trouble arises
LS600h/LS600hL_EE(OM50G20E)
■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 components when the vehicle is running at a
low speed for an extended period, such as in heavy traffic.
■When the 12-volt battery is removed or discharged
The hybrid system may not start. ( P. 504)
■Charging the 12-volt battery
The electricity stored in the 12-volt battery will discharge gradually even when the
vehicle is not in use, due to natural discharge and the draining effects of certain elec-
trical appliances. If the vehicle is left for a long time, the 12-volt battery may dis-
charge, and the hybrid system may be unable to start. (The 12-volt battery recharges
automatically while the hybrid system is operating.)
■When recharging or replacing the 12-volt battery
In some cases, it may not be possible to unlock the doors using the smart entry &
start system when the 12-volt battery is discharged. Use the wireless remote control
or the mechanical key to lock or unlock the doors.
■If the 12-volt battery is discharged
The information stored in the computer will be deleted.
If the 12-volt battery is discharged, have the vehicle inspected by your Lexus dealer.
Page 648 of 676

648
LS600h/LS600hL_EE(OM50G20E)
What to do if... (Troubleshooting)
What to do if... (Troubleshooting)
●If you lose your mechanical keys, new genuine mechanical keys
can be made by any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional. ( P. 143)
●If you lose your electronic keys, the risk of vehicle theft
increases significantly. Contact any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional
immediately. ( P. 148)
●Is the electronic key battery weak or depleted? (P. 532)
●Is the power switch in ON mode?
When locking the doors, turn the power switch off. ( P. 248)
●Is the electronic key left inside the vehicle?
When locking the doors, make sure that you have the elec-
tronic key on your person.
●The function may not operate properly due to the condition of
the radio wave. ( P. 159)
If you have a problem, check the following before contacting any
authorized Lexus dealer or repairer, or another duly qualified and
equipped professional.
The doors cannot be locked, unlocked, opened or closed
You lose your keys
The doors cannot be locked or unlocked