brake Lexus IS250 2012 Using the air conditioning system and defogger / LEXUS 2012 IS250,IS350 (OM53A87U) Workshop Manual

5
When trouble arises
471
5-2. Steps to take in an emergency
If a warning light turns on or a warning buzzer sounds...
Stop the vehicle immediately. Continuing to drive the vehicle may be dangerous.
The following warning indicates a possible problem in the brake system.
Immediately stop the vehi cle in a safe place and contact your Lexus
dealer.
*: Parking brake engaged warning buzzer:
 P. 4 8 4
Warning lightWarning light/Details
(U.S.A.)

(Canada)
Brake system warning light (warning buzzer)*
•Low brake fluid
• Malfunction in the brake booster system
This light also comes on when the parking brake is not
released. If the light turns off after the parking brake is fully
released the system is operating normally.
Calmly perform the following actions if any of the warning lights turn on or
flash. If a light turns on or flashes, bu t then turns off, this does not necessar-
ily indicate a malfunction in the system.

5
When trouble arises
473
5-2. Steps to take in an emergency
Follow the correction procedures.After taking the specified steps to co rrect the suspected problem, check
that the warning light turns off.
Warning lightWarning light/Details
(U.S.A.)

(Canada)
ABS warning light
Indicates a malfunction in:
•The ABS;
• The brake assist system.
Electric power steering system warning lightIndicates a malfunction in the EPS (Electric Power Steering)
system.
Slip indicatorIndicates a malfunction in:
• The VSC system;
•The TRAC system; or
• The hill-start assist control system
Warning lightWarning light/DetailsCorrection procedure
Open door warning light
(warning buzzer)
*1
Indicates that a door or the
trunk is not fully closed.
Check that all doors and the
trunk are closed.
Low fuel level warning lightRemaining fuel
(Approximately 2.9 gal. [11 L,
2.4 Imp. gal.] or less)
Refuel the vehicle.
(On the instru-ment cluster)
Driver’s seat belt reminder
light (warning buzzer)
*2
Warns the driver to fasten
his/her seat belt.Fasten the seat belt.

478
5-2. Steps to take in an emergency
CAUTION
■When the electric power steering warning light comes on
The steering wheel may become extremely heavy.
If the steering wheel becomes heavier than usual when operating, firmly hold and
operate it using more force than usual.
■If the tire pressure warning light comes on
Be sure to observe the following precautions. Failure to do so could cause loss of
vehicle control and result in death or serious injury.
●Stop your vehicle in a safe place as soon as possible. Adjust the tire inflation pres-
sure immediately.
●If the tire pressure warning light comes on even after tire inflation pressure adjust-
ment, it is probable that you have a flat ti re. Check the tires. If the tire is flat,
change to the spare tire and have the flat tire repaired by the nearest Lexus
dealer.
●Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, you could
lose control of the steering wheel or the brakes.
■If a blowout or sudden air leakage should occur
The tire pressure warning system may not activate immediately.

5
When trouble arises
485
5-2. Steps to take in an emergency
Indicates that the trunk is
not fully closed. flashes and a
buzzer sounds to indi-
cate that trunk is not fully
closed (with the vehicle
having reached a speed
of 3 mph [5 km/h]).
Close the trunk.
(Flashing)
(If equipped)
Indicates that the moon
roof is not fully closed
(with the “ENGINE
START STOP” switch
OFF and the driver’s
door opened).
Close the moon roof.
Indicates that the parking
brake is still engaged.
flashes and a
buzzer sounds to indi-
cate that the parking
brake is still engaged
(with the vehicle having
reached a speed of 3
mph [5 km/h]).
Release the parking
brake.
Indicates that the washer
fluid level is low.Add washer fluid.
Wa r n i n g m e s s a g eDetailsCorrection procedure

490
5-2. Steps to take in an emergency
Once
(Vehicles with an auto-matic transmission)
Indicates that a
door has been
opened or closed
and the “ENGINE
START STOP”
switch has been
switched twice to
ACCESSORY
mode from OFF.
Press the
“ENGINE START
STOP” switch
while applying the
brakes.
Once
(Vehicles with a manual transmission)
Indicates that a
door has been
opened or closed
and the “ENGINE
START STOP”
switch has been
switched twice to
ACCESSORY
mode from OFF.
Press the
“ENGINE START
STOP” switch
while depressing
the clutch pedal.

(Flashing)
Indicates that the
steering lock has
not released
within 3 seconds
of pressing the
“ENGINE START
STOP” switch.Press the
“ENGINE START
STOP” switch
again while turn-
ing the steering
wheel with the
brake pedal
depressed.
InteriorbuzzerExterior buzzerWa r n i n g m e s s a g eDetailsCorrection
procedure

492
5-2. Steps to take in an emergency
If you have a flat tire
Remove the flat tire and replace it with the spare provided.
■Before jacking up the vehicle
●Stop the vehicle on a hard, flat surface.
● Set the parking brake.
● Shift the shift lever to P (vehicle s with an automatic transmission)
or R (vehicles with a manual transmission).
● Stop the engine.
● Turn on the emergency flashers.
■ Location of the spare tire, jack and tools
Tool bag
(including towing eyelet) Jack
Jack handle
Spare tire
Ti g h t e nLoosen

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When trouble arises
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5-2. Steps to take in an emergency
CAUTION
■When the spare tire is attached
The vehicle speed may not be correctly detected, and the following systems may
not operate correctly:
●ABS & brake assist
●VSC
●TRAC
●EPS
●VDIM
●Navigation system (if equipped)
●Intuitive parking assist (if equipped)
●Cruise control
Also, not only can the following system not be utilized fully, it may actually negatively
effect the drive-train components:
●AWD system (if equipped)

502
5-2. Steps to take in an emergency
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 for about 15
seconds 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 ST ART STOP” switch for about 15
seconds while depressing the brak e 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

5
When trouble arises
503
5-2. Steps to take in an emergency
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

: If equipped

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When trouble arises
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5-2. Steps to take in an emergency
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. 141)
To start the engine: Press th e “ENGINE START STOP” switch
within 10 seconds after the buzz er sounds, keeping the brake
pedal depressed.
STEP1
STEP2
STEP3