2012 Lexus GS250 engine overheat

2264-2. Driving procedures
GS350/250_EE (OM30C36E)The parking brake is set or released automatically according to shift
lever operation.
Turns automatic mode on/off
When the shift lever is moved
out of P, the parking brake will
be released.
When the shift lever is moved
into P, the parking brake will
be set.
Operate the shift lever with the
brake pedal depressed.
Parking brake operation
When the engine switch is not in IGNITION ON mode, the parking brake
cannot be released using the parking brake switch.
When the engine switch is not in IGNITION ON mode, automatic mode
(automatic brake setting and releasing) is not available.
If the parking brake is operated repeatedly over a short period of time, the
system may restrict operation to prevent overheating. If this happens,
refrain from operating the parking brake. Normal operation will return after
about 1 minute.
Parking brake operation sound
When the parking brake operates, a motor sound (whirring sound) may be
heard. This does not indicate a malfunction.
Parking brake indicator light
Depending on the engine switch mode, the parking brake indicator light
will come on and stay on as described below:
IGNITION ON mode: Comes on until the parking brake is released.
Not in IGNITION ON mode: Stays on for approximately 15 seconds.
When the engine switch is turned off with the parking brake set, the parking
brake indicator light will stay on for about 15 seconds. This does not indi-
cate a malfunction.
Automatic mode

2484-3. Operating the lights and wipers
GS350/250_EE (OM30C36E)
Headlight cleaner switch
Press the switch to clean the
headlights.
The headlight cleaners can be operated when
The engine switch is in IGNITION ON mode and the headlight switch is
turned on.
Windshield washer linked operation
When the windshield washer is operated with the engine switch in IGNI-
TION ON mode and the headlights on, the headlight cleaners will operate
once. (P. 241)
Washer fluid can be sprayed on the headlights.
NOTICE
When the washer fluid tank is empty
Do not press the switch continually as the washer fluid pump may overheat.

3384-5. Using the driving support
GS350/250_EE (OM30C36E)
Reactivation of the TRC system linked to vehicle speed
When only the TRC system is turned off, the TRC system will turn on when
vehicle speed increases. However, when both TRC and VSC systems are
turned off, the systems will not turn on even when vehicle speed increases.
Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from
overheating when there is frequent steering input over an extended period of
time. The steering wheel may feel heavy as a result.
* Should this occur,
refrain from excessive steering input or stop the vehicle and turn the engine
off. The effectiveness will improve after a short while.
*: If the LKA (Lane-Keeping Assist) system cannot operate in this case, a
warning message will be shown on the multi-information display.
Operating conditions of emergency brake signal
When the following three conditions are met, the emergency brake signal
will operate:
The emergency flashers are off.
Actual vehicle speed is over 55 km/h (35 mph).
The brake pedal is depressed in a manner that cause the system to judge
from the vehicle deceleration that this is a sudden braking operation.
Automatic system cancelation of emergency brake signal
The emergency brake signal will turn off in any of the following situations:
The emergency flashers are turned on.
The brake pedal is released.
The system judges from the vehicle deceleration that is not a sudden brak-
ing operation.

6335-7. Other interior features
5
Interior features
GS350/250_EE (OM30C36E)
The seat heaters/seat ventilators can be used when
The engine switch is in IGNITION ON mode.
The seat heater timer control
The seat heater automatically switches from HiMidLoOff. The
switching timing differs depending on the temperature inside the cabin etc.
when the seat heater was operated.
Automatic operation of the seat heater during Eco drive mode
If the driving mode select switch is switched to Eco drive mode in cold tem-
peratures, the seat heater may be automatically operated to assist heating per-
formance.
Button lock function (vehicles with rear control panel)
To prevent inadvertent operation, some buttons on the rear armrest can be
locked. (P. 429)
Rear control panel illumination off function (vehicles with rear control panel)
Control panel illumination on the rear armrest can be turned off. (P. 429)
CAUTION
Burns (vehicles with seat heaters)
Use caution when seating the following persons in a seat with the seat
heater on to avoid the possibility of burns:
• Babies, small children, the elderly, the sick and the physically chal-
lenged
• Persons with sensitive skin
• Persons who are fatigued
• Persons who have taken alcohol or drugs that induce sleep (sleeping
drugs, cold remedies, etc.)
Do not cover the seat with anything when using the seat heater.
Using the seat heater with a blanket or cushion increases the temperature
of the seat and may lead to overheating.
Do not use seat heater more than necessary. Doing so may cause minor
burns or overheating.

737
7When trouble arises
GS350/250_EE (OM30C36E)
7-1. Essential information
Emergency flashers ........... 738
If your vehicle
has to be stopped
in an emergency .............. 7397-2. Steps to take in an emergency
If your vehicle needs
to be towed ..................... 740
If you think something
is wrong .......................... 747
Fuel pump shut off system 748
If a warning light turns on or
a warning buzzer sounds 749
If a warning message
is displayed ..................... 757
If you have a flat tire (vehicles
with a spare tire) ............. 782
If you have a flat tire (vehicles
without a spare tire) ........ 797
If the engine will not start . 815
If the shift lever cannot be
shifted from P ................. 817
If the parking brake
cannot be released........... 818
If the electronic key does not
operate properly .............. 821
If the vehicle battery
is discharged ................... 824
If your vehicle overheats .. 829
If the vehicle
becomes stuck................. 832

7747-2. Steps to take in an emergency
GS350/250_EE (OM30C36E)After taking the specified steps to correct the suspected problem,
check that the warning message and light go off.
Wa r n i n g m e s s a g eDetailsCorrection procedure
(If equipped)
Indicates that the pre-
crash safety system is
not currently functional
because the grille cover
or the sensor is dirty
This message also
appears when the
pre-crash safety sys-
tem is not functional
due to overheating.Check the grille cover
and the sensor and
clean them if they are
dirty.
In case of overheat-
ing, the system will
become functional
once the system
cools down.
Have the malfunction repaired immediately.
(Flashes)
Inte-
rior
buzzerExterior
buzzerWarning messageDetailsCorrection
procedure
Once
The electronic
key is not
detected when an
attempt is made to
start the engine.Start the
engine
with the
electronic
key pres-
ent.
(Flashes)

8307-2. Steps to take in an emergency
GS350/250_EE (OM30C36E)
If your vehicle 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. Carefully lift the hood after the steam subsides
and then restart the engine.
If you do not see steam:
Leave the engine running and carefully lift the hood.
Check to see if the cooling fan is operating.
If the fan is operating:
Wait until the temperature of the engine (shown on the instru-
ment panel) begins to fall and then stop the engine.
If the fan is not operating:
Stop the engine immediately and call any authorized Lexus
dealer or repairer, or another duly qualified and equipped profes-
sional.
After the engine has cooled
down sufficiently, check the
engine coolant level and
inspect the radiator core (radi-
ator) for any leaks.
If the engine compartment cover
needs to be removed: P. 6 6 1
1
2
3
4

8317-2. Steps to take in an emergency
7
When trouble arises
GS350/250_EE (OM30C36E)Add engine coolant if neces-
sary.
Water can be used in an emergency
if engine coolant is unavailable.
(P. 847)
Have the vehicle inspected at the nearest authorized Lexus dealer
or repairer, or another duly qualified and equipped professional as
soon as possible.
Overheating
If you observe the following, your vehicle may be overheating:
The engine coolant temperature gauge enters the red zone or a loss of power
is experienced.
Steam comes out from under the hood.
5
CAUTION
When inspecting under the hood of your vehicle
Observe the following precautions.
Failure to do so may result in serious injury such as burns.
If steam is seen coming from under the hood, do not open the hood until
the steam has subsided. The engine compartment may be very hot.
Keep hands and clothing away from the fans, etc. while the engine is oper-
ating.
Do not loosen the radiator cap while the
engine and radiator are hot.
High temperature steam or coolant
could spray out.