2007 Lexus GS450h Using the audio system / LEXUS 2007 GS450H THROUGH JUNE 2006 PROD. OWNER'S MANUAL (OM30727U)

5
When trouble arises
469
5-2. Steps to take in an emergency
When the electronic key battery is discharged
Locking and unlocking the doors, unlocking the trunk and key linked functions
DoorsUsing the mechanical key in order
to per
form the following opera -
tions:
Locks all doors
Closes the windows/moon roof
(turn and hold)
Unlocks the door
Turning the key rearward unlocks
the driver's door. Turning the key
once again unlocks the other
doors.
Opens the windows/moon roof
(turn and hold)
Tr u n k
Turn the mechanical key clock-
wise to open.
If the electronic key battery is di scharged, the doors and trunk can be
opened by the mechanical key. The hybrid system can be still started by fol
-
lowing the procedure.

470
5-2. Steps to take in an emergency
Starting the hybrid system
Put the shift lever in “P” and apply the brakes.Hold the electronic k
ey close to
the power switch (within 0.4 in. [10
mm]). Make sure that the button
side of the key is facing away from
the power switch.
An alarm will sound to indicate that
the start function cannot detect the
key with the depleted battery if any
of the doors will be opened and
closed while this operation.
Press the power switch within 5 seconds after the buzzer sounds,
keeping the brake pedal depressed.
If the hybrid system still cannot be started, contact your Lexus dealer.
STEP1
STEP2
■Replacing the key battery
As this procedure is the temporary measure, it is recommended that the electronic
k
ey battery be replaced immediately. ( P. 3 9 3 )
STEP3

5
When trouble arises
471
5-2. Steps to take in an emergency
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 call your Lexus dealer, Roadside Assistance or Lexus Customer
Ser
vice.
If you have a set of jumper (or booster) cables and a second vehicle
with a 12 volt battery, you can jump start your Lexus following the steps
below.
Open the trunk using the mechanical key. ( P. 4 6 9 )
Connecting the jumper cables. If required, remove all vent pl ugs fr
om the booster battery. Lay a
cloth over the open vents on the booster batter
y. (This helps reduce
the explosion hazard, personal injuries and burns.)
Positive (+) battery terminal on your vehicle.
Positive (+) battery terminal on the second vehicle.
Negative (-) battery terminal on the second v
ehicle.
Negative (-) battery terminal or your vehicle. Start the engine of the second v
ehicle. Increase the engine
speed slightly and maintain at that le
vel for approximately 5
minutes to recharge the 12 volt battery of your vehicle.
Open and close any of the door s with the po
wer switch “OFF”.
STEP1
STEP2
STEP3
STEP4

472
5-2. Steps to take in an emergency
■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, etc.
■When the 12 volt battery is removed or discharged
The hybrid system may not start. ( P. 3 7 2 )
Also, the following systems must be initialized.
●Po w e r w i n d o w s (P. 5 3 )
●Moon roof (P. 5 6)
●Variable gear ratio steering (P. 1 5 1 )
●Tire pressure warning system (P. 3 7 7 )
●Intuitive parking assist (P. 1 5 1)
Maintain the engine speed on th e second vehicle and turn the
power switch to the “IG-ON” mo de, then start the vehicle’s
hybrid system.
Make sure the “READY” light co mes on. If the light does not
come on, contact your Lexus dealer.
Once the vehicle’s hybrid system has started, remove the
jumper cables in the exact reverse or
der in which they were
connected.
Once the hybrid system starts, have the v
ehicle checked at your Lexus
dealer as soon as possible.
STEP5
STEP6
STEP7

5
When trouble arises
473
5-2. Steps to take in an emergency
CAUTION
■Avoiding battery fires or explosions
Observe the following precautions to prevent accidentally igniting the flammable
gas that may be emitted from the battery.
●Make sure the jumper cable is connected to the correct terminal and that it is not
unintentionally in contact with any pa rt other than the intended terminal.
●Do not allow the jumper cables to come into contact with the “+” and “-” termi-
nals.
●Do not allow open flame or use matches, cigarette lighters or smoke near the
battery.
■Battery precautions
The battery contains poisonous and corrosive acidic electrolyte, while related parts
contain lead and lead compounds. Observe the following precautions when han-
dling the battery:
●When working with the battery, always wear safety glasses and take care not to
allow any battery fluids (acid) to come into contact with skin, clothing or the vehi-
cle body.
●Do not lean over the battery.
●If the battery fluid comes into contact with the skin or eyes, immediately wash the
affected area with water and seek medical attention. 
Place a wet sponge or cloth over the affected area until medical attention can be
received.
●Always wash your hands after handling the battery support, terminals, and other
battery-related parts.
●Do not allow children near the battery.

474
5-2. Steps to take in an emergency
NOTICE
■To prevent damaging the vehicle
Hybrid vehicles cannot be push-started.
■When handling jumper cables
Be careful that the jumper cables do not become tangled in the cooling fan or any
of the belts when connecting or disconnecting them.

5
When trouble arises
475
5-2. Steps to take in an emergency
If your vehicle overheats
■Electric motor (traction motor) and inverter
If the message “HYBRID SYSTEM OVERHEAT” is displayed on the
multi-information display.
■ Ga
soline engine
If the needle of the engine co olant temper
ature gauge enters the
red zone, the gasoline engine has probably overheated.
Observe the following steps: Stop the vehicle in a safe place and turn of
f the automatic air
conditioning system.
Check to see if steam is coming out from under the hood.
If you see steam: 
Stop the hybrid system and carefully lift the hood.
If you do not see steam: Leave the hybrid system running and carefully lift the hood.
Remove the engine compartment cover. ( P. 362 )
Check to see if the cooling fan is operating.
If the fan is operating: 
Wait until the engine coolant temperature gauge begins to
fall and then stop the hybrid s
ystem.
If the fan is not operating: 
Stop the hybrid system immed iately and call y
our local
Lexus dealer.
After the hybrid system has
cooled do
wn sufficiently, check
the coolant level and inspect the
radiator core (radiator) for any
leaks.
STEP1
STEP2
STEP3
STEP4
STEP5

476
5-2. Steps to take in an emergency
■Overheating
In the following situations, your vehicle may be overheating.
●The message “HYBRID SYSTEM OVERHEAT” is displayed on the multi-infor-
mation display.
●The engine coolant temperatur e gauge enters the red zone or a loss of power is
experienced.
●Steam is coming from under the hood.
CAUTION
■To prevent an accident or injury when in specting under the hood of your vehicle
●Keep hands and clothing away from the fan and engine drive belt while the hybrid
system is running.
●Do not loosen the radiator cap while the hybrid system and radiator are hot. 
Serious injury, such as burns, may resu lt from hot coolant and steam released
under pressure.
Add coolant if required.
Water can be used in an emer -
gency measure if coolant is
una
vailable. ( P. 4 8 4 )
Have the vehicle checked at your nearest Lexus dealer as soon as pos -
sible.
STEP6