Page 825 of 1014
801 6-3. Do-it-yourself maintenance
6
Maintenance and care
GS450h_300h_OM_OM30D53E_(EE)
The upper part of the 12-volt battery*
*: When one or more of the fuses in this unit are blown, the unit needs to be
replaced as a whole.
FuseAmpereCircuit
1EPB30Parking brake
2LUG-J/B BATT40Luggage compartment junction block
3EPS80Electric power steering
4ARS80Dynamic Rear Steering
5MAIN220Engine compartment junction block
Page 845 of 1014

819
7When trouble arises
GS450h_300h_OM_OM30D53E_(EE)7-1. Essential information
Emergency flashers ........... 820
If your vehicle
has to be stopped
in an emergency .............. 8217-2. Steps to take in an emergency
If your vehicle needs
to be towed ..................... 822
If you think something
is wrong .......................... 829
If a warning light turns on
or a warning buzzer
sounds ............................. 830
If a warning message
is displayed ..................... 838
If you have a flat tire (vehicles
with a spare tire) ............. 870
If you have a flat tire (vehicles
without a spare tire) ........ 884
If the hybrid system
will not start .................... 902
If the shift lever cannot be
shifted from P ................. 904
If the parking brake
cannot be released........... 905
If the electronic key does not
operate properly .............. 908
If the 12-volt battery
is discharged ....................911
If your vehicle overheats .. 915
If the vehicle
becomes stuck................. 923
Page 847 of 1014

821
7 7-1. Essential information
When trouble arises
GS450h_300h_OM_OM30D53E_(EE)
If your vehicle has to be stopped in an emergency
Steadily step on the brake pedal with both feet and firmly depress
it.
Do not pump the brake pedal repeatedly as this will increase the effort
required to slow the vehicle.
Shift the shift lever to N.
If the shift lever is shifted to N
After slowing down, stop the vehicle in a safe place by the road.
Stop the hybrid system.
If the shift lever cannot be shifted to N
Keep depressing the brake pedal with both feet to reduce vehicle
speed as much as possible.
To stop the hybrid system,
press and hold the power
switch for 2 consecutive sec-
onds or more, or press it
briefly 3 times or more in suc-
cession.
Stop the vehicle in a safe place by the road.
Only in an emergency, such as if it becomes impossible to stop the
vehicle in the normal way, stop the vehicle using the following
procedure:
1
2
3
4
3
Press and hold for 2 seconds or
more or press briefly 3 times or
4
5
Page 850 of 1014
8237-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30D53E_(EE)
If a tow truck is not available in
an emergency, your vehicle may
be temporarily towed using a
cable or chain secured to the
emergency towing eyelet. This
should only be attempted on hard
surfaced roads for short distances
at under 30 km/h (18 mph).
A driver must be in the vehicle to
steer and operate the brakes. The
vehicle’s wheels, drive train,
axles, steering and brakes must
be in good condition.
Emergency towing
Page 854 of 1014

8277-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30D53E_(EE)
Before emergency towing
Release the parking brake.
Shift the shift lever to N.
Turn the power switch to ACCESSORY (hybrid system off) or ON (hybrid
system operating) mode.
CAUTION
Observe the following precautions.
Failure to do so may result in death or serious injury.
When transporting the vehicle
Caution while towing
Use extreme caution when towing the vehicle.
Avoid sudden starts or erratic driving maneuvers which place excessive
stress on the emergency towing eyelets and the cables or chains. Always
be cautious of the surroundings and other vehicles while towing.
If the hybrid system is off, the power assist for the brakes and steering will
not function, making steering and braking more difficult.
Installing towing eyelets to the vehicle
Make sure that towing eyelets are installed securely.
If not securely installed, towing eyelets may come loose during towing.
1
2
3
Be sure to transport the vehicle with the
rear wheels raised or with all four wheels
raised off the ground. If the vehicle is
towed with the rear wheels contacting
the ground, the drivetrain and related
parts may be damaged or the motor may
generate electricity. If the motor gener-
ates electricity, depending on the state of
the damage or malfunction, a fire may
dt hti it
Page 856 of 1014

829
7 7-2. Steps to take in an emergency
When trouble arises
GS450h_300h_OM_OM30D53E_(EE)
If you think something is wrong
Fluid leaks under the vehicle.
(Water dripping from the air conditioning after use is normal.)
Flat-looking tires or uneven tire wear
Engine coolant temperature gauge needle continually points
higher than normal.
Changes in exhaust sound
Excessive tire squeal when cornering
Strange noises related to the suspension system
Pinging or other noises related to the hybrid system
Engine missing, stumbling or running roughly
Appreciable loss of power
Vehicle pulls heavily to one side when braking
Vehicle pulls heavily to one side when driving on a level road
Loss of brake effectiveness, spongy feeling, pedal almost
touches the floor
If you notice any of the following symptoms, your vehicle proba-
bly needs adjustment or repair. Contact any authorized Lexus
dealer or repairer, or another duly qualified and equipped profes-
sional as soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms
Page 857 of 1014
8307-2. Steps to take in an emergency
GS450h_300h_OM_OM30D53E_(EE)
If a warning light turns on or a warning buzzer
sounds
The following warning indicates a possible problem in the brake
system. Immediately stop the vehicle in a safe place and contact
any authorized Lexus dealer or repairer, or another duly qualified
and equipped professional.
Calmly perform the following actions if any of the warning lights
comes on or flashes. If a light comes on or flashes, but then goes
off, this does not necessarily indicate a malfunction in the system.
However, if this continues to occur, have the vehicle inspected by
any authorized Lexus dealer or repairer, or another duly qualified
and equipped professional.
Stop the vehicle immediately. Continuing to drive the vehicle
may be dangerous.
Wa r n i n g
lightWarning light/Details
Brake system warning light (warning buzzer)
• Low brake fluid
• Malfunction in the electronically controlled brake sys-
tem
Page 859 of 1014
8327-2. Steps to take in an emergency
GS450h_300h_OM_OM30D53E_(EE)
ABS warning light
Indicates a malfunction in:
• The ABS; or
• The brake assist system
Wa r n i n g
lightWarning light/Details