2008 Lexus GS450h battery

433
4-3. Do-it-yourself maintenance
4
Maintenance and care
GS_HV_U
December 27, 2007 1:38 pm
CAUTION
■Emergency measures regarding electrolyte
●If electrolyte gets in your eyes
Flush your eyes with clean water for at least 15 minutes and get immediate medi-
cal attention. If possible, continue to apply water with a sponge or cloth while
traveling to the nearest medical facility.
●If electrolyte gets on your skin 
Wash the affected area thoroughly. If you feel pain or a burning sensation, seek
medical attention immediately.
●If electrolyte gets on your clothes 
It can soak through clothing on to your skin. Immediately take off the clothing and
follow the procedure above if necessary.
●If you accidentally swallow electrolyte 
Drink a large quantity of water or milk. Fo llow with milk of magnesia, beaten raw
egg or vegetable oil. Get emergency medical attention immediately.
NOTICE
■When recharging the battery
Never recharge the battery while the hybrid system is on. Also, be sure all accesso-
ries are turned off.

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.

461
4-3. Do-it-yourself maintenance
4
Maintenance and care
GS_HV_U
December 27, 2007 1:38 pm
FuseAmpereCircuit
8IG210
Multiport fuel injection system/
sequential multiport fuel injection
system, noise filter
9EFI No.210Fuel system, exhaust system
10H-LP R LWR15Headlight low beam (right)
11H-LP L LWR15Headlight low beam (left)
12D/C CUT30DOME, MPX-B
13IGCT No.37. 5Hybrid battery (traction battery)
14IGCT No.27. 5Hybrid system
15MPX-B7. 5
Power windows, door control system,
power seat, electronically controlled
brake system, combination switch,
electric tilt and telescopic steering,
gauges and meters
16DOME7. 5Interior lights, foot lights, vanity light,
gauges and meters
17ABS MAIN110Electronically controlled brake sys-
tem
18ABS MOTOR30ABS
19ABS MAIN210Electronically controlled brake sys-
tem
20F/ P M P25Fuel system
21EFI25
EFI2, multiport fuel injection system/
sequential multiport fuel injection
system
22INJ20
Multiport fuel injection system/
sequential multiport fuel injection
system

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
509
5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
Wa r n i n g m e s s a g eDetailsCorrection procedure
(If equipped, flashing)
Yo u r v e h i c l e i s n e a r i n g
the vehicle ahead (in
radar cruise mode).Slow the vehicle by apply-
ing the brakes.
The hybrid system has
overheated.Stop and check. 
( P. 5 3 8 )
The vehicle is unable to
drive over 60 mph until
the transmission warms
up.
Wait until the transmission
warms up.
(Flashing)
The hybrid battery (trac-
tion battery) is low.Stop the vehicle and shift
the shift lever to “P”.

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.