Page 489 of 573

4888-2. Steps to take in an emergency
IS350/250_U (OM53758U)
■Doors
Use the mechanical key (P. 99) in
order to perform the following oper-
ations:
Locks all the doors
Closes the windows and moon
roof (turn and hold)
*
Unlocks the door
Turning the key rearward unlocks the
driver’s door. Turning the key once
again within 5 seconds unlocks the
other doors.
Opens the windows and moon roof (turn and hold)*
*
: This setting must be customized at your Lexus dealer.
■Tr u n k
Turn the mechanical key clockwise
to open.
If the electronic key does not operate properly
If communication between the electronic key and vehicle is interrupted ( P.
116) or the electronic key cannot be used because the battery is depleted, the
smart access system with push-button start and wireless remote control can-
not be used. In such cases, the doors and trunk can be opened and the engine
can be started by following the procedure below.
Locking and unlocking the doors, un locking the trunk and key linked
functions
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Page 490 of 573

4898-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53758U)
Ensure that the shift lever is in P and depress the brake pedal.
Touch the Lexus emblem side of the
electronic key to the engine switch.
When the electronic key is detected, a
buzzer sounds and the engine switch
will turn to IGNITION ON mode.
When the smart access system with
push-button start is deactivated in cus-
tomization setting, the engine switch will
turn to ACCESSORY mode.
Firmly depress the brake pedal and check that is shown on the multi-
information display.
Press the engine switch.
In the event that the engine still cannot be started, contact your Lexus dealer.
■Stopping the engine
Shift the shift lever to P and press the engine switch as you normally do when stopping
the engine.
■Replacing the key battery
As the above procedure is a temporary measure, it is recommended that the electronic
key battery be replaced immediatel y when the battery is depleted. (P. 4 2 7 )
■Changing engine switch modes
Release the brake pedal and press the engine switch in step above.
The engine does not start and modes will be changed each time the switch is pressed.
( P. 1 6 0 )
■When the electronic key does not work properly
●Make sure that the smart access system wi th push-button start has not been deacti-
vated in the custom ization setting. If it is off, turn the function on.
(Customizable features P. 5 2 5 )
●Check if battery-saving mo de is set. If it is set, cancel the function. ( P. 115)
Starting the engine
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Page 491 of 573
4908-2. Steps to take in an emergency
IS350/250_U (OM53758U)
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.
Open the hood ( P. 3 9 9 )
Remove the engine cover.
IS250
Raise the front of the engine cover to
detach it from the clips and then pull
the cover to detach it from the
brackets on the rear bar.
IS350
Raise the rear of the engine cover to
remove the rear clip, and then raise
the front of the engine cover to
remove the two front clips.
If the vehicle battery is discharged
The following procedures may be used to start the engine if the vehicle’s bat-
tery is discharged.
You can also call your Lexus dealer or a qualified repair shop.
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Page 492 of 573

4918-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53758U)
Connect the jumper cables according to the following procedure:Connect a positive jumper cable clamp to the positive (+) battery terminal
on your vehicle.
Connect the clamp on the other end of the positive cable to the positive (+)
battery terminal on the second vehicle.
Connect a negative cable clamp to the negative (-) battery terminal on the
second vehicle.
Connect the clamp at the other end of the negative cable to a solid, station-
ary, unpainted metallic point away from the battery and any moving parts,
as shown in the illustration.
Start the engine of the second vehicle. Increase the engine speed slightly and
maintain at that level for approximately 5 minutes to recharge the battery of
your vehicle.
Open and close any of the doors of your vehicle with the engine switch off.
Maintain the engine speed of the second vehicle and start the engine of your
vehicle by turning the engine switch to IGNITION ON mode.
Once the vehicle’s engine has started, remove the jumper cables in the exact
reverse order from which they were connected.
Once the engine starts, have the vehicle inspected at your Lexus dealer as soon
as possible.3
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Page 493 of 573

4928-2. Steps to take in an emergency
IS350/250_U (OM53758U)
■Starting the engine when the battery is discharged
The engine cannot be started by push-starting.
■To prevent battery discharge
●Turn off the headlights and the audio system while the engine 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.
■Charging the battery
The electricity stored in the battery will discharge gradually even when the vehicle is not
in use, due to natural discharge and the draining effects of certain electrical appliances. If
the vehicle is left for a long time, the battery may discharge, and the engine may be
unable to start. (The battery recharges automatically during driving.)
■When recharging or replacing the battery
●Make sure that the key is not inside the vehicle when recharging or replacing the bat-
tery. The key may be locked in the vehicle if the alarm is activated. ( P. 7 2 )
●In some cases, it may not be possible to unlock the doors using the smart access system
with push-button start when the battery is discharged. Use the wireless remote control
or the mechanical key to lock or unlock the doors.
●The engine may not start on the first attempt after the battery has recharged but will
start normally after the second attempt. This is not a malfunction.
●The engine switch mode is memorized by the vehicle. When the battery is recon-
nected, the system will return to the mode it was in before the battery was discharged.
Before disconnecting the battery, turn the engine switch off.
If you are unsure what mode the engine switch was in before the battery discharged, be
especially careful when reconnecting the battery.
Page 494 of 573

4938-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53758U)
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 each jumper cable is connected to the correct terminal and that it is not
unintentionally in contact with any other than the intended terminal.
●Do not allow the other end of the jumper cable connected to the “+” terminal to come
into contact with any other parts or metal surfaces in the area, such as brackets or
unpainted metal.
●Do not allow the + and - clamps of the jump er cables to come into contact with each
other.
●Do not smoke, use matches, cigarette lighters or allow open flame near the battery.
■Battery precautions
The battery contains poisonous and corrosive acidic electrolyte, while related parts
contain lead and lead comp ounds. Observe the following precautions when handling
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 vehicle body.
●Do not lean over the battery.
●In the event that 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 bat-
tery-related parts.
●Do not allow children near the battery.
NOTICE
■When handling jumper cables
When connecting the jumper cables, ensure th at they do not become entangled in the
cooling fans or engine drive belt.
Page 495 of 573
4948-2. Steps to take in an emergency
IS350/250_U (OM53758U)
●The needle of the engine coolant temperature gauge (P. 81) enters the red
zone or a loss of engine power is experienced. (For example, the vehicle
speed does not increase.)
●Steam comes out from under the hood.
Stop the vehicle in a safe place and tu rn off the air conditioning system, and
then stop the engine.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the engine has cooled down
sufficiently, inspect the hoses and
radiator core (radiator) for any
leaks.
Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact your Lexus
dealer.
If your vehicle overheats
The following may indicate that your vehicle is overheating.
Correction procedures
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Page 496 of 573
4958-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53758U)
The coolant level is satisfactory if it is
between the “FULL” and “LOW”
lines on the reservoir.Reservoir
“FULL”
“LOW”
Add coolant if necessary.
Water can be used in an emergency if
coolant is unavailable.
Start the engine and turn the air conditioning system on to check that the radi-
ator cooling fan operates and to check for coolant leaks from the radiator or
hoses.
The fan operates when the air conditioning system is turned on immediately after a
cold start. Confirm that the fan is operating by checking the fan sound and air flow. If it
is difficult to check these, turn the air conditioning system on and off repeatedly.
(The fan may not operate in freezing temperatures.)
If the fan is not operating:
Stop the engine immediately and contact your Lexus dealer.
If the fan is operating:
Have the vehicle inspected at the nearest Lexus dealer.
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