2012 Lexus GS350 overheating

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2 2. Instrument cluster
Instrument cluster
GS350/250_EE (OM30C36E)
The meters and display illuminate when
The engine switch is in IGNITION ON mode.
Instrument panel brightness adjustment
The instrument panel brightness levels when the tail lights are on and off can
be adjusted individually. However, when the surroundings are bright (day-
time, etc.), turning on the tail lights will not change the instrument panel
brightness.
Limitation of brightness adjustment
The brightness of the instrument panel lights is automatically adjusted based
on the light sensor detecting how bright the surroundings are. However, if the
instrument panel brightness has been manually set to either the brightest or
darkest setting, the automatic adjustment will not be performed.
ECO lamp and SPORT lamp
When sport mode is selected, SPORT lamp (red) will illuminate.
When all of the following conditions are satisfied and Eco-friendly driving,
ECO lamp (blue) will illuminate. (ECO lamp will become brighter the more
Eco-friendly driving you perform. Also, while the acceleration exceeds
Zone of Eco driving, ECO lamp turns off. (P. 109) However, when Eco
drive mode is selected, while the acceleration exceeds Zone of Eco driving,
ECO lamp does not turn off.):
• Driving with the shift lever in D
• Paddle shift switch is not operated.
• Either normal mode or Eco drive mode is selected.
• The vehicle speed is approximately 130 km/h (80 mph) or below.
Customization
Settings (e.g. on/off operation of ECO lamp) can be changed.
(Customizable features P. 857)
NOTICE
To prevent damage to the engine and its components
Do not let the indicator needle of the tachometer enter the red zone, which
indicates the maximum engine speed.
The engine may be overheating if the engine coolant temperature gauge is
in the red zone (H). In this case, immediately stop the vehicle in a safe
place, and check the engine after it has cooled completely. (P. 829)

1954-1. Before driving
4
Driving
GS350/250_EE (OM30C36E)
CAUTION
When taking a nap in the vehicle
Always turn the engine off. Otherwise, if you accidentally move the shift
lever or depress the accelerator pedal, this could cause an accident or fire
due to engine overheating. Additionally, if the vehicle is parked in a poorly
ventilated area, exhaust gases may collect and enter the vehicle, leading to
death or a serious health hazard.
When braking
When the brakes are wet, drive more cautiously.
Braking distance increases when the brakes are wet, and this may cause
one side of the vehicle to brake differently than the other side. Also, the
parking brake may not securely hold the vehicle.
If the power brake assist function does not operate, do not follow other
vehicles closely and avoid hills or sharp turns that require braking.
In this case, braking is still possible, but the brake pedal should be
depressed more firmly than usual. Also, the braking distance will
increase.
The brake system consists of 2 individual hydraulic systems; if one of the
systems fails, the other will still operate. In this case, the brake pedal
should be depressed more firmly than usual and the braking distance will
increase.
If this happens, do not continue to drive the vehicle. Have your brakes
fixed immediately.
If the vehicle becomes stuck
Do not spin the wheels excessively when any of the tires is up in the air, or
the vehicle is stuck in sand, mud, etc. This may damage the driveline com-
ponents or propel the vehicle forward or backward, causing an accident.

2084-1. Before driving
GS350/250_EE (OM30C36E)
If the engine overheats
Towing a loaded trailer up a long, steep incline in temperatures
exceeding 30C (85F) may result in the engine overheating. If
the engine coolant temperature gauge indicates that the engine is
overheating, turn the air conditioning off immediately, leave the
road and stop the vehicle in a safe place. (P. 829)
When parking the vehicle
Always place wheel chocks under the wheels of both the vehicle
and trailer. Firmly set the parking brake and shift the shift lever
to P.
CAUTION
To avoid accident or injury
Do not tow a trailer when the compact spare tire is installed on your vehi-
cle.
Do not tow the vehicle when the tire installed is repaired with the emer-
gency tire puncture repair kit.
Vehicle speed in towing
Observe the legal maximum speeds for trailer towing.
Before descending hills or long declines
Reduce speed and downshift. However, never downshift suddenly while
descending steep or long downhill grades.
Operation of the brake pedal
Do not hold the brake pedal depressed often or for long periods of time.
Doing so may result in the brake overheating or reduce braking effects.
NOTICE
For vehicles with an emergency tire puncture repair kit (if equipped)
Do not tow anything if a tire that has been repaired using the emergency tire
puncture repair kit is installed. The load on the tire may cause unexpected
damage to the tire.

2124-2. Driving procedures
GS350/250_EE (OM30C36E)
When the steering lock cannot be released
Steering lock motor overheating prevention
To prevent the steering lock motor from overheating, the motor may be sus-
pended if the engine is turned on and off repeatedly in a short period of time.
In this case, refrain from operating the engine. After about 10 seconds, the
steering lock motor will resume functioning.
When “Check Entry & Start System” will be displayed on the multi-informa-
tion display
The system may be malfunctioning. Have the vehicle inspected by any
authorized Lexus dealer or repairer, or another duly qualified and equipped
professional immediately.
If the electronic key battery is depleted
P. 8 1 5
Operation of the engine switch
When operating the engine switch, one short, firm press is enough. If the
switch is pressed improperly, the engine may not start or the engine switch
mode may not change. It is not necessary to press and hold the switch.
If attempting to restart the engine immediately after turning the engine
switch off, the engine may not start in some cases. After turning the engine
switch off, please wait a few seconds before restarting the engine.
If the smart entry & start system has been deactivated in a customized setting
P. 8 2 1 “Steering Lock active” will be displayed
on the multi-information display.
Check that the shift lever is set in P. Press
the engine switch while turning the steer-
ing wheel left and right.

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

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4 4-2. Driving procedures
Driving
GS350/250_EE (OM30C36E)
When there is a malfunction in the system
Warning lights and/or warning message will turn on or flash. (P. 749, 757)
Depending on the condition, the parking brake indicator light may flash.
Usage in winter time
P. 3 5 9
NOTICE
When parking the vehicle
Before you leave the vehicle, set the parking brake, shift the shift lever to P
and make sure that the vehicle does not move.
When the system malfunctions
Stop the vehicle in a safe place and check the warning messages.
When the parking brake cannot be released due to a malfunction
Use the parking brake release tool to manually release the parking brake.
(P. 818)
Driving the vehicle with the parking brake set will lead to brake compo-
nents overheating, which may affect braking performance and increase
brake wear.

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
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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.