2013 Lexus GS450h engine overheat

TABLE OF CONTENTS6
GS450h_U (OM30D01U)
6-3. Do-it-yourself maintenanceDo-it-yourself service precautions..................................631
Hood ............................................... 634
Positioning a floor jack............. 635
Engine compartment ................637
12-volt battery ..............................647
Tires....................................................651
Tire inflation pressure ................. 661
Wheels ........................................... 664
Air conditioning filter ............... 666
Electronic key battery.............. 668
Checking and replacing fuses...............................................670
Headlight aim ..............................685
Light bulbs .................................... 687
7-1. Essential information Emergency flashers .................. 702
If your vehicle has to be stopped in an emergency.... 703 7-2. Steps to take in an emergency
If your vehicle needs to be towed................................ 704
If you think something is wrong ..................710
If a warning light turns on or a warning buzzer sounds........ 711
If a warning message is displayed .................................. 721
If you have a flat tire ................... 749
If the hybrid system will not start ................................ 762
If the shift lever cannot be shifted from P ...................... 764
If the parking brake cannot be released ................................. 765
If the electronic key does not operate properly ...................... 767
If the 12-volt battery is discharged..............................770
If your vehicle overheats .......... 774
If the vehicle becomes stuck ..............................................778
7When trouble arises

17Pictorial index
GS450h_U (OM30D01U)
Windshield wipers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 219
Precautions against winter season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 319
To prevent freezing (windshield wiper de-icer)
* . . . . . . . . . . . . . . . . . . . . P. 385
Precautions against car wash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 618
Fuel filler door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 2 2 7
Refueling method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 227
Fuel type/fuel tank capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 784
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 651
Tire size/inflation pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 790
Winter tires/tire chain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 319
Checking/rotation/tire pressure warning system. . . . . . . . . . . . . . . . . . . . .P. 651
Coping with flat tires. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 749
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 634
Opening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 634
Engine compartment cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 638
Engine oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 7 8 5
Coping with overheat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 774
Warning messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 728
Headlights/parking lights/daytime running ligh ts . . . . . . . . . . . . . . . . . . P. 213
Fog lights
* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 218
Turn signal lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 205
Tail lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 213
Stop lights
Brake Hold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P . 210
License plate lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 213
Back-up lights
Shifting the shift lever to R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 199
Side marker lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 213
4
5
6
7
Light bulbs of the exterior lights for driving
(Replacing method: P. 687, Watts: P. 791)
*: If equipped
8
9
10
11
12
13
14
15

GS450h_U (OM30D01U)
932. Instrument cluster
2
Instrument cluster
■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. 9 2 ) H o w e v e r, w h e n E c o d r i v e
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 80 mph (130 km/h) or below.
■Tachometer
Hybrid System Indicator switches to the ta chometer when driving mode is in sport
mode.
■Engine speed
On hybrid vehicles, engine speed is precis ely 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 vehi-
cle operation and driving conditions are the same.
■Customization
Settings (e.g. on/off operatio n of ECO lamp) can be changed.
(Customizable features P. 8 0 7 )
NOTICE
■To prevent damage to the engine and its components
●Do not let the indicator needle of the tachometer enter the red zone, which indi-
cates 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. 7 74 )

176
GS450h_U (OM30D01U)
4-1. Before driving
CAUTION
Observe the following precautions.
Failure to do so may result in death or serious injury.
■When driving the vehicle
●During normal driving, do not turn off the hybrid system. Turning the hybrid sys-
tem off while driving will not cause loss of steering or braking control, but the
power assist to these systems will be lost. This will make it more difficult to steer
and brake, so you should pull over and stop the vehicle as soon as it is safe to do
so.
However, in the event of an emergency, such as if it becomes impossible to stop
the vehicle in the normal way: P. 7 0 3
●Use engine braking (downshift) to maintain a safe speed when driving down a
steep hill.
Using the brakes continuously may cause the brakes to overheat and lose effec-
tiveness. ( P. 1 9 9 )
●Do not adjust the positions of the steering wheel, the seat, or the inside or outside
rear view mirrors while driving.
Doing so may result in a loss of vehicle control.
●Always check that all passengers’ arms, heads or other parts of their body are not
outside the vehicle.
●Do not drive in excess of the speed limit. Even if the legal speed limit permits it, do
not drive over 85 mph (140 km/h) unless your vehicle has high-speed capability
tires. Driving over 85 mph (140 km/h) may result in tire failure, loss of control and
possible injury. Be sure to consult a tire dealer to determine whether the tires on
your vehicle are high-speed capability tires or not before driving at such speeds.

178
GS450h_U (OM30D01U)
4-1. Before driving
CAUTION
■If you hear a squealing or scraping noise (brake pad wear limit indicators)
Have the brake pads checked and replaced by your Lexus dealer as soon as possi-
ble.
Rotor damage may result if the pads are not replaced when needed.
Front brakes only: Moderate levels of brake pad and disc wear allow enhanced
front braking power. As a result, the discs may wear more quickly than conven-
tional brake discs. Therefore, when replacing the brake pads, Lexus recommends
that you also have the thickness of the discs measured.
It is dangerous to drive the vehicle when the wear limits of the brake pads and/or
those of the brake discs are exceeded.
■When the vehicle is stopped
●Do not depress the accelerator pedal unnecessarily.
If the vehicle is in any gear other than P or N, the vehicle may accelerate suddenly
and unexpectedly, causing an accident.
●In order to prevent accidents due to the vehicle rolling away, always keep
depressing the brake pedal while the “READY” indicator is on, and apply the
parking brake as necessary.
●If the vehicle is stopped on an incline, in order to prevent accidents caused by the
vehicle rolling forward or backward, always depress the brake pedal and securely
apply the parking brake as needed.
●Avoid revving or racing the engine.
Running the engine at high speed whil e the vehicle is stopped may cause the
exhaust system to overheat, which could result in a fire if combustible material is
nearby.

GS450h_U (OM30D01U)
2934-5. Using the driving support systems
4
Driving
■When the message is displayed on the multi-information display showing that
TRAC has been disabled even if the VSC OFF switch has not been pressed
TRAC cannot be operated. Contact your Lexus dealer.
■Sounds and vibrations caused by the ABS, brake assist, VSC and TRAC systems
●A sound may be heard from the engine compartment when the brake pedal is
depressed repeatedly, when the hybrid syst em is started or just after the vehicle
begins to move. This sound does not indicate that a malfunction has occurred in
any of these systems.
●Any of the following conditions may occur when the above systems are operating.
None of these indicates that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard after the vehicle comes to a stop.
■EPS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be heard.
This does not indicate a malfunction.
■Reactivation of the TRAC/VSC systems
Even after the TRAC/VSC systems have been turned off, turning the hybrid system
off and then on again will automatically reactivate the TRAC/VSC systems.
■Reactivation of the TRAC sy stem linked to vehicle speed
When only the TRAC system is turned off, the TRAC system will turn on when vehi-
cle speed increases. However, when both TRAC/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 overheat-
ing when there is frequent steering input ov er an extended period of time. The steer-
ing 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 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.

7377-2. Steps to take in an emergency
GS450h_U (OM30D01U)
7
When trouble arises
Indicates that the hybrid
system output is limited
because the engine oil is
overheatedDrive the vehicle at a safe
speed until the warning
message disappears.
Indicates that the vehicle
is unable to drive over 65
mph (110 km/h) until the
transmission warms up
Wait until the transmis-
sion warms up.
Indicates that remaining
fuel is approximately 2.6
gal. (10.0 L, 2.2 Imp.gal.)
or less
Refuel the vehicle.
Indicates that the power
switch is turned off or
turned to ACCESSORY
mode and the driver’s
door is opened while the
lights are turned on
Tu r n t h e l i g h t s o f f .
Indicates that the driver’s
door was opened with the
shift position in any posi-
tion other than P
Shift the shift position to P.
Wa r n i n g m e s s a g eDetailsCorrection procedure
(Flashes)
(Flashes)

774
GS450h_U (OM30D01U)
7-2. Steps to take in an emergency
If your vehicle overheats
●The needle of the engine coolant temperature gauge enters the red
zone:
The engine may be overheating.
●“Hybrid System Overheat” is shown on the multi-information display:
The power control unit may be overheating.
■If the needle of the engine coolant temperature gauge enters the red
zone
Stop the vehicle in a safe place an d turn off the air conditioning sys-
tem.
Check to see if steam is coming out from the engine area.
If you see steam:
Stop the hybrid system. Carefull y lift the hood after the steam sub-
sides and then restart the hybrid system.
If you do not see steam:
Leave the hybrid system operating and carefully lift the hood.
Check to see if the cooling fans are operating.
If the fans are operating:
Wait until the engine coolant temperature ga uge begins to fall and
then stop the hybrid system.
If the fans are not operating:
Stop the hybrid system immediately and call your Lexus dealer.
The following may indicate that your vehicle is overheating:
Correction procedures
1
2
3