2010 Lexus IS250C engine

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When trouble arises
497
5-2. Steps to take in an emergency
10_IS250C/350C_U
If the engine will not start
If the engine will not start, even though correct starting procedures are
being followed (
→P. 142), consider each of the following points.
■The engine will not start even when the starter motor operates
normally.
One of the following may be the cause of the problem.
●There may not be sufficient fuel in the vehicle’s tank.
Refuel the vehicle.
● The engine may be flooded.
Try to restart the engine once more following correct starting
procedures. ( →P. 142)
● There may be a malfunction in the engine immobilizer system.
(→ P. 9 3 )
■ The starter motor turns over slowly, the interior lights and head-
lights are dim, or the horn does not sound or sounds at a low vol-
ume.
One of the following may be the cause of the problem.
● The battery may be discharged. ( →P. 506)
● The battery terminal connections may be loose or corroded.
■ The starter motor does not turn ov er, the interior lights and head-
lights 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 battery terminals may be disconnected.
● The battery may be discharged. ( →P. 506)
● There may be a malfunction in the steering lock system.
Contact your Lexus dealer if the problem cannot be repaired, or if
repair procedures are unknown.

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5-2. Steps to take in an emergency
10_IS250C/350C_U
Emergency start function
When the engine does not start, the following steps can be used as an
interim measure to start the engine if the “ENGINE START STOP” switch
is functioning normally.Vehicles with an automatic transmission Set the parking brake.
Put the shift lever in P.
Set the “ENGINE START STOP” switch to ACCESSORY mode.
Press and hold the “ENGINE START STOP” switch about 15 sec-
onds while depressing the brake pedal firmly.
Vehicles with a manual transmission Set the parking brake.
Put the shift lever in N.
Set the “ENGINE START STOP” switch to the ACCESSORY
mode.
Push and hold the “ENGINE START STOP” switch about 15 sec-
onds while depressing the brake pedal and clutch pedal firmly.
Even if the engine can be started using the above steps, the system may
be malfunctioning. Have the vehicle checked by your Lexus dealer.
STEP1
STEP2
STEP3
STEP4
STEP1
STEP2
STEP3
STEP4

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5-2. Steps to take in an emergency
10_IS250C/350C_U
If the shift lever cannot be shifted from P
If the shift lever cannot be shifted with your foot on the brake, there may be
a problem with the shift lock system (a system to prevent accidental opera-
tion of the shift lever). Have the vehicle inspected by your Lexus dealer
immediately.
The following steps may be used as an emergency measure to ensure that
the shift lever can be shifted.
Set the parking brake.
Turn the “ENGINE START STOP” switch to ACCESSORY
mode.
Depress the brake pedal.
Pry the cover up with a flathead
screwdriver or equivalent.
Press the shift lock override but-
ton.
The shift lever can be shifted
while the button is pressed.
STEP1
STEP2
STEP3
STEP4
STEP5

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5-2. Steps to take in an emergency
10_IS250C/350C_U
If the electronic key does not operate properly
Locking and unlocking the doors, unlocking the trunk and key linked functions
Doors
Remove the cover on the driver’s
door handle using the mechanical
key (→P. 25) in order to perform
the following operations.
Locks both side doors
Unlocks the door
Turning the key rearward unlocks
the driver's door. Turning the key
once again unlocks the passenger’s
door.
Return the cover to the original
position after use.
If communication between the electronic key and vehicle is interrupted
(→ P. 32) or the electronic key cann ot be used because the battery is
depleted, the smart access system with push-button start and wireless
remote control cannot be used. In such cases, the doors and trunk can be
opened or the engine can be started by following the procedure below.

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5-2. Steps to take in an emergency
10_IS250C/350C_U
Changing “ENGINE START STOP” switch modes and starting the engine
Automatic transmissionShift the shift lever to 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.
To change “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. 142)
To start the engine: Press the “ENGINE START STOP” switch
within 10 seconds after the buzzer sounds, keeping the brake
pedal depressed.
STEP1
STEP2
STEP3

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5-2. Steps to take in an emergency
10_IS250C/350C_UManual transmission
Shift the shift lever to N and depress the clutch pedal.
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.
To change “ENGINE START ST OP” switch modes: Within 10
seconds of the buzzer sounding, release the clutch pedal and
press the “ENGINE START STOP” switch. Modes can be
changed each time the switch is pressed.
(→ P. 142)
To start the engine: Press the “ENGINE START STOP” switch
within 10 seconds after the buzzer sounds, keeping the clutch
pedal depressed.
In the event that the engine still cannot be started, contact your Lexus
dealer.
STEP1
STEP2
STEP3

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5-2. Steps to take in an emergency
10_IS250C/350C_U
■Stopping the engine
For vehicles with an automatic transmission: Shift the shift lever to P and press the
“ENGINE START STOP” switch as you normally do when stopping the engine.
For vehicles with a manual transmission: Shift the shift lever to N position and press
the “ENGINE START STOP” 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 elec-
tronic key battery be replaced immediately when the battery depletes. (→P. 4 2 5 )

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5-2. Steps to take in an emergency
10_IS250C/350C_U
If the vehicle battery is discharged
The following procedures may be used to start the engine if the vehicle’s
battery 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.
Remove the engine compartment covers. ( →P. 394)
Connecting the jumper cables.
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 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 with the “ENGINE START
STOP” switch OFF.
STEP1
STEP2
STEP3
STEP4