ECU Lexus IS250 2015 TIPS FOR THE NAVIGATION SYSTEM / LEXUS 2015 IS250/350 (OM53C50U) Repair Manual

3906-4. Using the other interior features
IS350/250_U (OM53C50U)
“SOS” button
LED light indicators
Microphone
LEXUS Enform Safety Connect 
: If equipped
Safety Connect is a subscription-based telematics service that uses Global
Positioning System (GPS) data and embe dded cellular technology to provide
safety and security features to subscribers. Safety Connect is supported by
Lexus’ designated response center, wh ich operates 24 hours per day, 7 days
per week.
Safety Connect service is available by su bscription on select, telematics hard-
ware-equipped vehicles.
By using the Safety Connect service, yo u are agreeing to be bound by the
Telematics Subscription Service Agreement and its Terms and Conditions, as
in effect and amended from time to time, a current copy of which is available
at Lexus.com. All use of the Safety Connect service is subject to such then-
applicable Terms and Conditions.
System components
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4067-2. Maintenance
IS350/250_U (OM53C50U)
Vehicle interior
ItemsCheck points
Accelerator pedal• The accelerator pedal should move smoothly (with- out uneven pedal effort or catching).
Automatic transmission
“Park” mechanism• When parked on a slope and the shift lever is in P, isthe vehicle securely stopped?
Brake pedal
• Does the brake pedal move smoothly?
• Does the brake pedal have appropriate clearance
from the floor? ( P. 5 1 8 )
• Does the brake pedal have the correct amount of
free play? ( P. 5 1 8 )
Brakes
• The vehicle should not pull to one side when the
brakes are applied.
• The brakes should work effectively.
• The brake pedal should not feel spongy.
• The brake pedal should not get too close to the floor when the brakes are applied.
Head restraints• Do the head restraints move smoothly and lock
securely?
Indicators/buzzers• Do the indicators and buzzers function properly?
Lights• Do all the lights come on?
Parking brake
• Moves smoothly?
• When parked on a slope and the parking brake is on,is the vehicle securely stopped?
Seat belts•Do the seat belt s operate smoothly?
• The seat belts should not be damaged.
Seats• Do the seat controls operate properly?
Steering wheel
• Does the steering wheel rotate smoothly?
• Does the steering wheel have the correct amount of free play?
• There should not be an y strange sounds coming
from the steering wheel.

4537-3. Do-it-yourself maintenance
7
Maintenance and care
IS350/250_U (OM53C50U)
CAUTION
■Replacing light bulbs
●Turn off the lights. Do not attempt to replace the bulb immediately after turning off the
lights.
The bulbs become very hot and may cause burns.
●Do not touch the glass portion of the light bulb with bare hands. When it is unavoid-
able to hold the glass portion, use and hold with a clean dry cloth to avoid getting
moisture and oils on the bulb.
Also, if the bulb is scratched or dropped, it may blow out or crack.
●Fully install light bulbs and any parts used to secure them. Failure to do so may result
in heat damage, fire, or water entering the headlight unit. This may damage the head-
lights or cause condensation to build up on the lens.
■Discharge headlights (if equipped)
●Contact your Lexus dealer before replacing the discharge headlights (including light
bulbs).
●Do not touch the discharge headlight’s high voltage socket when the headlights are
turned on.
An extremely high voltage of 30000 V will be discharged and could result in death
or serious injury by electric shock.
●Do not attempt to take apart or repair the headlight bulbs, connectors, power supply
circuits, or related components.
Doing so could result in electric shock and death or serious injury.
■To prevent damage or fire
●Make sure bulbs are fully seated and locked.
●Check the wattage of the bulb before installin g to prevent heat damage.
●Vehicles with discharge headlights:
While the headlights are turned on, and for a
short time after they have been turned off,
metal components at the rear of the headlight
assembly will be extremely hot. To prevent
burns, do not touch these metal components
until you are certain they have cooled down.
Metal components

4578-1. Essential information
8
When trouble arises
IS350/250_U (OM53C50U)
Steadily step on the brake pedal with both feet and firmly depress it.
Do not pump the brake pedal repeatedly as this will increase the effort required to
slow the vehicle.
Shift the shift lever to N.
If the shift lever is shifted to N
After slowing down, stop the vehicle in a safe place by the road.
Stop the engine.
If the shift lever cannot be shifted to N
Keep depressing the brake pedal with both feet to reduce vehicle speed as
much as possible.
To stop the engine, press and hold
the engine switch for 2 consecutive
seconds or more, or press it briefly 3
times or more in succession.
Stop the vehicle in a safe place by the road.
If your vehicle has to be stopped in an emergency
Only in an emergency, such as if it becomes impossible to stop the vehicle in
the normal way, stop the vehicle using the following procedure:
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2
3
4
3
Press and hold for 2 seconds or more
or press briefly 3 times or more
4
CAUTION
■If the engine has to be turned off while driving
Power assist for the brakes and steering wheel will be lost, making the brake pedal
harder to depress and the steering wheel heavier to turn. Decelerate as much as possi-
ble before turning off the engine.
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4608-2. Steps to take in an emergency
IS350/250_U (OM53C50U)
If your Lexus is transported by a flatbed
truck, it should be tied down at the
locations shown in the illustration.
If you use chains or cables to tie down
your vehicle, the angles shaded in black
must be 45.
Do not overly tighten the tie downs or
the vehicle may be damaged.
If a tow truck is not available in an emergency, your vehicle may be temporarily
towed using a cable or chain secured to the emergency towing eyelet. This
should only be attempted on hard surfaced roads for 50 miles (80 km) at low
speeds.
A driver must be in the vehicle to steer and operate the brakes. The vehicle’s
wheels, drive train, axles, steering an d brakes must be in good condition.
Using a flatbed truck
Emergency towing

4618-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53C50U)
Take out the towing eyelet. (P. 4 8 7 )
Remove the eyelet cover using a flat-
head screwdriver.
To protect the bodywork, place a rag
between the screwdriver and the vehi-
cle body as shown in the illustration.
Insert the towing eyelet into the hole
and tighten partially by hand.
Tighten down the towing eyelet
securely using a wheel nut wrench
or hard metal bar.
Securely attach a cable or chain to the towing eyelet.
Take care not to damage the vehicle body.
Enter the vehicle being towed and start the engine.
If the engine does not start, turn th e engine switch to IGNITION ON mode.
Shift the shift lever to N and release the parking brake.
When the shift lever cannot be shifted: P. 4 9 8
Emergency towing procedure
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4638-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53C50U)
CAUTION
■While towing
●When towing using a cables or chains, avoid sudden starts, etc. which place excessive
stress on the towing eyelets, cables or chains. The towing eyelets, cables or chains
may become damaged, broken debris ma y hit people and cause serious damage.
●Do not turn the engine switch off.
There is a possibility that the steering wheel is locked and cannot be operated.
■Installing towing eyelet to the vehicle
Make sure that towing eyelet is installed securely.
If not securely installed, towing ey elet may come loose during towing.
NOTICE
■To prevent damage to the vehicle when towing using a wheel-lift type truck (2WD
models)
●Do not tow the vehicle from the rear when the engine switch is off. The steering lock
mechanism is not strong enough to hold the front wheels straight.
●When raising the vehicle from the rear, en sure adequate ground clearance for towing
at the opposite end of the raised vehicle. Without adequate clearance, the vehicle
could be damaged while being towed from the rear.
■To prevent damage to the vehicle when towing using a wheel-lift type truck (AWD
models)
When raising the vehicle, ensure adequate ground clearance for towing at the oppo-
site end of the raised vehicle. Without adequate clearance, the vehicle could be dam-
aged while being towed.
■To prevent body damage when to wing with a sling-type truck
Do not tow with a sling-type truck, either from the front or rear.

4698-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53C50U)
■SRS warning light
This warning light system monitors the airbag sensor assembly, front impact sensors, side
impact sensors (front door), side impact sensors (front), side impact sensors (rear),
driver’s seat position sensor, driver’s seat belt buckle switch, front passenger occupant
classification system, “AIR BAG ON” indica tor light, “AIR BAG OFF” indicator light,
front passenger’s seat belt buckle switch, seat belt pretensioner assemblies, airbags,
interconnecting wiring and power sources. ( P. 3 8 )
■Front passenger detection sensor, seat belt reminder and warning buzzer
If luggage is placed on the front passenger seat, the front passenger detection sensor
may cause the warning light to flash and the wa rning buzzer to sound even if a passenger
is not sitting in the seat.
■If the malfunction indicator lamp comes on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fuel tank immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The light will go off after several driving trips.
If the light does not go off even after severa l trips, contact your Lexus dealer as soon as
possible.
■Electric power steering system warning light (warning buzzer)
When the battery charge becomes insufficie nt of the voltage temporarily drops, the
electric power steering system warning light may come on and the warning buzzer may
sound.
■When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level. Pushing the tire
pressure warning reset switch will not tu rn off the tire pressure warning light.
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such as natural air
leaks and tire inflation pressure changes caused by temperature. In this case, adjusting
the tire inflation pressure will turn off the warning light (after a few minutes).
■When a tire is replaced with the spare tire
The compact spare tire is not equipped with a tire pressure warning valve and transmit-
ter. If a tire goes flat, the tire pressure warning light will not turn off even though the flat
tire has been replaced with the spare tire.
■Conditions that the tire pressure warning system may not function properly
P. 4 2 8
■If the tire pressure warning light frequently comes on after blinking for 1 minute
If the tire pressure warning light frequently comes on after blinking for 1 minute when the
engine switch is turned to IGNITION ON mo de, have it checked by your Lexus dealer.
■Warning buzzer
In some cases, the buzzer may not be heard due to being in a noisy location or audio
sound.

4848-2. Steps to take in an emergency
IS350/250_U (OM53C50U)
Once
• When the doors were unlockedwith the mechanical key and then
the engine switch was pressed,
the electronic key could not be
detected in the vehicle.
• The electronic key could not be detected in the vehicle even after
the engine switch was pressed
two consecutive times.
 Touch the electronic key to the
engine switch while depressing
the brake pedal.
Once
During an engine starting proce-
dure in the event that the electronic
key was not functioning properly
( P. 500), the engine switch was
touched with the electronic key.
 Press the engine switch within
10 seconds of the buzzer sound-
ing.

Indicates that:
• With the engine switch off, the
doors were unlocked and then the
driver's door was opened and
closed
• The engine switch was turned to ACCESSORY mode without
starting the engine
• The shift lever was shifted to P or N from another shift position with
the engine switch in IGNITION
ON mode.
 Press the engine switch while
depressing the brake pedal.
Once
The engine switch has been turned
off with the shift lever in a position
other than P or N.
Shift the shift lever to P.
Once
After the engine switch has been
turned off with the shift lever in a
position other than P, the shift lever
has been shifted to P.
Turn the engine switch off.
Interior
buzzerExteriorbuzzerWa r n i n g m e s s a g eDetails/Actions
(Flashes)
(Flashes)
(Flashes)

4908-2. Steps to take in an emergency
IS350/250_U (OM53C50U)
Remove the luggage mat.
Remove the spacer and tool tray.
Loosen the center fastener that
secures the spare tire.
If the center fastener cannot be turned
by hand, use the wheel nut wrench that
is stored in the trunk. (To secure the tire,
tighten the center fastener by hand. Do
not use the wrench or other tools.)
Taking out the spare tire
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CAUTION
■When storing the spare tire
Be careful not to catch fingers or other body parts between the spare tire and the body
of the vehicle.