2008 Lexus GS350 engine

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When trouble arises
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5-2. Steps to take in an emergency
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May 13, 2008 5:14 pm
Tr u n kTurn the mechanical key clock-
wise to open.
Changing “ENGINE START STOP” switch modes and starting the
engine
Put the shift lever in “P” and apply the brakes. Touch the Lexus emblem side of
the electronic key to the
“ENGINE START STOP” switch.
An alarm will sound to indicate that
the start function cannot detect the
electronic key that is touched to
the “ENGINE START STOP”
switch if any of the doors is opened
and closed while the key is touched
to the switch.
STEP1
STEP2

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5-2. Steps to take in an emergency
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May 13, 2008 5:14 pm
To change the “ENGINE START STOP” switch modes: Within 10
seconds of the buzzer sounding , release the brake pedal and
press the “ENGINE START STOP” switch. Modes can be
changed each time the switch is pressed. (
P. 122)
To start the engine: Press the “ENGINE START STOP” switch
within 10 seconds after the buzz er sounds, keeping the brake
pedal depressed.
If the “ENGINE START STOP” switch still cannot be operated, contact
your Lexus dealer.
■Stopping the engine
Shift the shift lever to “P” and press th e “ENGINE START STOP” switch as you nor-
mally do when stopping the engine.
■Replacing the key battery
As the above procedure is the temporary measure, it is recommended that the
electronic key battery be replaced i mmediately when the battery depletes.
(  P. 440)
STEP3

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5-2. Steps to take in an emergency
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May 13, 2008 5:14 pm
If the 12 volt battery is discharged
The following procedures may be used to start the engine if the 12 volt bat-
tery is discharged. 
You can call your Lexus dealer or qualified repair shop.
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 door using the mechani cal key, then open the hood.
GS350: Remove the engine compartment covers.
Connecting the jumper cables.
GS460
STEP1
STEP2

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5-2. Steps to take in an emergency
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GS350
Positive (+) battery terminal on your vehicle.
Positive (+) battery terminal on the second vehicle.
Negative (-) battery terminal on the second vehicle.
Connect the jumper cable to ground on your vehicle as shown. 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 battery of your vehicle.
Open and close any of the do ors with the “ENGINE START
STOP” switch is OFF.
STEP3
STEP4

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5-2. Steps to take in an emergency
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May 13, 2008 5:14 pm
■Starting the engine when the 12 volt battery is discharged
The engine cannot be started by push-starting.
■To prevent 12 volt battery discharge
●Turn off the headlights and the audio system while the engine is turned off.
●Turn off any unnecessary electrical compon ents 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 following systems must be initialized.
●Tire pressure warning system (P. 4 2 2 )
●Intuitive parking assist (P. 5 0 7 )
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.
Maintain the engine speed on th e second vehicle and turn the
“ENGINE START STOP” switch to the IGNITION ON mode,
then start the vehicle’s engine.
Once the vehicle’s engine ha s started, remove the jumper
cables in the exact reverse ord er in which they were con-
nected.
Once the engine starts, have the ve hicle checked at your Lexus dealer
as soon as possible.STEP5
STEP6

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5-2. Steps to take in an emergency
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May 13, 2008 5:14 pm
If your vehicle overheats
If your engine overheats:
Stop the vehicle in a safe place and turn off the air conditioning
system.
Check to see if steam is coming out from under the hood.
If you see steam: 
Stop the engine and car efully lift the hood.
If you do not see steam: Leave the engine running and carefully lift the hood.
Remove the engine compartment cover. ( P. 4 0 8 )
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 engine.
If the fan is not operating: 
Stop the engine immediately and call your local Lexus
dealer.
After the engine has cooled
down sufficiently, check the
coolant level and inspect the
radiator core (radiator) for any
leaks.STEP1
STEP2
STEP3
STEP4
STEP5

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5-2. Steps to take in an emergency
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May 13, 2008 5:14 pm
■Overheating
In the following situations, your vehicle may be overheating.
●The engine coolant temperature 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
engine is running.
●Do not loosen the radiator cap while the engine and radiator are hot. 
Serious injury, such as burns, may resu lt from hot coolant and steam released
under pressure.
Add coolant if necessary.
Water can be used in an emer-
gency measure if coolant is
unavailable. ( P. 5 4 6 )
Have the vehicle checked at your nearest Lexus dealer as soon as pos-
sible.
STEP6

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NOTICE
■When adding coolant
Wait until the engine has cooled down before adding coolant.
When adding coolant, do so slowly. Adding cool coolant to a hot engine too quickly
can cause damage to the engine.