2013 Lexus GS300h overheating

901-2. Hybrid system
GS450h_300h_OM_OM30D53E_(EE)
NOTICE
Hybrid battery air vents
Do not put foreign objects near the air vents. The hybrid battery (traction
battery) may overheat and be damaged.
Clean the air vents regularly to prevent the hybrid battery (traction bat-
tery) from overheating.
Do not wet or allow foreign substances to enter the air vents as this may
cause a short circuit and damage the hybrid battery (traction battery).
Do not carry large amounts of water such as water cooler bottles in the
vehicle. If water spills onto the hybrid battery (traction battery), the bat-
tery may be damaged. Have the vehicle inspected by any authorized
Lexus dealer or repairer, or another duly qualified and equipped profes-
sional.

1132. Instrument cluster
2
Instrument cluster
GS450h_300h_OM_OM30D53E_(EE)
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 vehicle is stopped or the
acceleration exceeds Zone of Eco driving, ECO lamp turns off. P. 1 1 2 ]
However, when Eco drive mode is selected, while the vehicle is stopped or
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.
Tachometer
Hybrid System Indicator switches to the tachometer when driving mode is in
sport mode.
Engine speed
On hybrid vehicles, engine speed is precisely controlled in order to help
improve fuel efficiency and reduce exhaust emissions etc.
There are times when the engine speed that is displayed may differ even
when vehicle operation and driving conditions are the same.
Customization
Settings (e.g. on/off operation of ECO lamp) can be changed.
(Customizable features: P. 944)
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. 915)

2334-1. Before driving
4
Driving
GS450h_300h_OM_OM30D53E_(EE)
CAUTION
When taking a nap in the vehicle
Always turn the hybrid system off. Otherwise, if you accidentally move the
shift lever or depress the accelerator pedal, this could cause an accident or
fire due to hybrid system 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 electronically controlled brake system does not operate, do not fol-
low other vehicles closely and avoid hills or sharp turns that require brak-
ing.
In this case, braking is still possible, but the brake pedal should be
depressed more firmly than usual. Also, the braking distance will
increase. Have your brakes fixed immediately.
The brake system consists of 2 or more individual hydraulic systems; if
one of the systems fails, the other(s) will still operate. In this case, the
brake pedal should be depressed more firmly than usual and the braking
distance will increase. Have your brakes fixed immediately.

2474-1. Before driving
4
Driving
GS450h_300h_OM_OM30D53E_(EE)
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. 915)
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 a trailer when the tire installed is repaired with the emergency
tire puncture repair kit.
Do not use cruise control (if equipped) or dynamic radar cruise control (if
equipped) when trailer towing.
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.

2514-2. Driving procedures
4
Driving
GS450h_300h_OM_OM30D53E_(EE)
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 hybrid system is turned on and off repeatedly in a short period
of time. In this case, refrain from operating the hybrid system. 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 “READY” indicator does not come on
If the “READY” indicator does not come on when you press the power
switch with the shift lever in P and the brake pedal depressed, contact any
authorized Lexus dealer or repairer, or another duly qualified and equipped
professional immediately.
If the hybrid system is malfunctioning
P. 8 4 0
If the electronic key battery is depleted
P. 9 0 2
Operation of the power switch
When operating the power switch, one short, firm press is enough. If the
switch is pressed improperly, the hybrid system may not start or the power
switch mode may not change. It is not necessary to press and hold the
switch.
If attempting to restart the hybrid system immediately after turning the
power switch off, the hybrid system may not start in some cases. After turn-
ing the power switch off, please wait a few seconds before restarting the
hybrid system.
If the smart entry & start system has been deactivated in a customized setting “Steering Lock active” will be displayed
on the multi-information display.
Check that the shift lever is set in P. Press
the power switch while turning the steer-
ing wheel left and right.

2704-2. Driving procedures
GS450h_300h_OM_OM30D53E_(EE)
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 power switch is not in ON mode, the parking brake cannot be
released using the parking brake switch.
When the power switch is not in 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 power switch mode, the parking brake indicator light will
come on and stay on as described below:
ON mode: Comes on until the parking brake is released.
Not in ON mode: Stays on for approximately 15 seconds.
When the power 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

271
4 4-2. Driving procedures
Driving
GS450h_300h_OM_OM30D53E_(EE)
When there is a malfunction in the system
Warning lights and/or warning message will turn on or flash. (P. 830, 838)
Depending on the condition, the parking brake indicator light may flash.
Usage in winter time
P. 4 3 4
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. 905)
Driving the vehicle with the parking brake set will lead to brake compo-
nents overheating, which may affect braking performance and increase
brake wear.

4034-5. Using the driving support system
4
Driving
GS450h_300h_OM_OM30D53E_(EE)
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 hybrid
system off. The EPS system should return to normal within 10 minutes.
*: 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.