2008 Lexus GS450h key battery

141
2-1. Driving procedures
2
When driving
GS_HV_U
May 13, 2008 3:11 pm
■When the electronic key battery is discharged
P. 4 5 4
■Conditions affecting operation
P. 3 9
■Leak detection pump
Several hours after the hybrid system is turned off, you may hear a sound coming
from underneath the luggage compartment for several minutes. This is normal
operation and does not indicate a malfunction.
CAUTION
■When starting the hybrid system
Always start the hybrid system while sitting in the driver’s seat. Do not press the
accelerator pedal while starting the hybrid system under any circumstances. 
Doing so may cause an accident resu lting in death or serious injury.
■Stopping the hybrid system in an emergency
If you want to stop the hybrid system in an emergency while driving the vehicle,
push and hold the “POWER” switch for more than 3 seconds. 
However, do not touch the “POWER” switch while driving except in an emergency.
If the hybrid system stops while the vehicle is being driven, this could lead to an
unexpected accident.
NOTICE
■To prevent 12 volt battery discharge
Do not leave the “POWER” switch in ACCESSORY or ON mode for long periods
without the hybrid system on.
■When starting the hybrid system
●Do not race the hybrid system.
●If the hybrid system becomes difficult to st art or stalls frequently, have the hybrid
system checked immediately.

160
2-3. Operating the lights and windshield wipers
GS_HV_U
May 19, 2008 9:00 pm
■Automatic light off system
The headlights and tail lights turn off 30 seconds after all doors are closed if the
“POWER” switch has been switched to ACCESSORY mode or turned OFF while
the headlights are turned on. (The lights turn off immediately if the button on the
key is pressed after all doors are locked.)
To turn the lights on again, switch to ON mode, or turn the light switch off once and
then back to the or position.
■Automatic headlight leveling system
The level of the headlights is automatica lly adjusted according to the number of
passengers and the loading condition of the vehicle to ensure that the headlights do
not interfere with other road users.
■If the indicator flashes...
It may indicate a malfunction in the system. Contact your Lexus dealer.
■Customization that can be configured at Lexus dealer
Settings (e.g. light sensor sensitivity) can be changed. 
(Customizable features P. 5 7 2 )
NOTICE
■To prevent 12 volt battery discharge
Do not leave the lights on longer than necessary when the hybrid system is off.

Maintenance and care4
401
GS_HV_U
December 12, 2007 3:30 pm
4-1. Maintenance and 
care ............................... 402
Cleaning and protecting 
the vehicle exterior............ 402
Cleaning and protecting 
the vehicle interior ............. 405 4-2. Maintenance .................. 408
Maintenance 
requirements........................ 408
General maintenance ........... 410
Emission inspection and 
maintenance (I/M) 
programs ................................ 413
4-3. Do-it-yourself 
maintenance ................. 414
Do-it-yourself service 
precautions ............................ 414
Hood ............................................ 417
Positioning a floor jack .......... 418
Engine compartment ........... 420
Tires............................................ 435
Tire inflation pressure........... 445
Wheels ...................................... 449
Air conditioning filter ............ 451
Electronic key battery.......... 454
Checking and replacing 
fuses ........................................ 456
Headlight aim ........................... 471
Light bulbs ................................. 474

454
4-3. Do-it-yourself maintenance
GS_HV_U
December 27, 2007 1:38 pm
Electronic key battery
Replace the battery with a new one if it is discharged.
■You will need the following items:
●Flathead screwdriver
● Small Phillips-head sc rewdriver
● Lithium battery (CR1632)
■ Replacing the battery
Take out the mechanical key.
Remove the cover.
Remove the depleted battery.
Insert a new battery with the “+”
terminal facing up.
STEP1
STEP2
STEP3

455
4-3. Do-it-yourself maintenance
4
Maintenance and care
GS_HV_U
December 27, 2007 1:38 pm
■If the electronic key battery is discharged
The following symptoms may occur.
●The smart access system with push-button start and wireless remote control will
not function properly.
●The operational range is reduced.
■Use a CR1632 lithium battery
●Batteries can be purchased at your Lexus dealer, jewelers, or camera stores.
●Replace only with the same or equivalent type recommended by your Lexus
dealer.
●Dispose of used batteries according to the local laws.
CAUTION
■Removed battery and other parts
Keep away from children. 
These parts are small and if swallowed by a child they can cause choking.
NOTICE
■For normal operation after replacing the battery
Observe the following precautions to prevent accidents.
●Always work with dry hands. 
Moisture may cause the battery to rust.
●Do not touch or move any other comp onents inside the electronic key.
●Do not bend the battery terminals.

When trouble arises5
481
GS_HV_U
December 12, 2007 3:30 pm
5-1. Essential information..... 482If your vehicle needs 
to be towed ........................... 482
If you think something is  wrong ..................................... 488
Event data recorder .............. 489 5-2. Steps to take in an

emergency .................... 491
If a warning light turns on or a 
warning buzzer sounds... ... 491
If a warning message is 
displayed................................ 500
If you have a flat tire (Vehicles 
with standard tires) ............... 517
If you have a flat tire (Vehicles 
with run-flat tires)................ 527
If the hybrid system will 
not start .................................. 528
If the shift lever cannot be 
shifted from “P”.................... 529
If you lose your keys .............. 530
If the electronic key does 
not operate properly........... 531
If the 12 volt battery is 
discharged ............................ 534
If your vehicle overheats ..... 538
If the vehicle becomes 
stuck......................................... 541

5
When trouble arises
515
5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
InteriorbuzzerExterior buzzerWa r n i n g m e s s a g eDetailsCorrection
procedure
Once
(Flashing)
The electronic key
battery is low.Replace the
battery.
( P. 4 5 4 )

An open door has
been closed and
the “POWER”
switch has been
turned twice to
the ACCES-
SORY mode from
OFF.
Press the
“POWER”
switch while
applying the
brakes.

(Flashing)
The steering lock
has not released
within 3 seconds
of pressing the
“POWER” switch.
The “POWER”
switch indicator
will flash green for
15 seconds.Press the
“POWER”
switch again
while turn-
ing the
steering
wheel with
the brake
pedal
depressed.

528
5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
If the hybrid system will not start
If the hybrid system will not start even though correct starting procedures
are being followed (
P. 138), consider each of the following points.
■The hybrid system will not start ev en if you are carrying the cor-
rect electronic key
One of the following may be the cause of the problem.
● The electronic key battery may be discharged. ( P. 5 3 1 )
● There may not be sufficient fuel in the vehicle’s tank. 
Add fuel to the vehicle.
● There may be a malfunction in the steering lock system.
● There may be a malfunction in the immobilizer system. 
( P. 88)
■ The interior lights and headlights are dim, or the horn does not
sound or sounds at a low volume
One of the following may be the cause of the problem.
● The 12 volt battery may be discharged. ( P. 5 3 4 )
● The 12 volt battery terminal connections may be loose or cor-
roded.
■ The interior lights and headlights do not turn on, or the horn does
not sound
One of the following may be the cause of the problem.
●One or both of the 12 volt battery terminals may be discon-
nected.
● The 12 volt battery may be discharged. ( P. 5 3 4 )
Contact your Lexus dealer if the problem cannot be repaired, or if
repair procedures are unknown.