Page 448 of 620

4466-3. Do-it-yourself maintenance
LS600hL_U(OM50E41U)
■Power control unit coolant reservoir
The coolant level is satisfactory if it is between the “F” and “L” lines on
the reservoir when the hybrid system is cold.
Reservoir cap
“F” line
“L” line
If the level is on or below the “L”
line, add coolant up to the “F” line.
( P. 5 3 0 )
■Coolant selection
Only use “Toyota Super Long Life Coolant” or a similar high quality ethylene glycol
based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life
hybrid organic acid technology.
U.S.A.:
“Toyota Super Long Life Coolant” is a mixture of 50% coolant and 50% deionized
water. (Minimum temperature: -31 F [-35C])
Canada:
“Toyota Super Long Life Coolant” is a mixture of 55% coolant and 45% deionized
water. (Minimum temperature: -44 F [-42C])
For more details about coolant, contact your Lexus dealer.
■If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine/power control unit coolant reservoir caps,
drain cock and water pump.
If you cannot find a leak, have your Lexus dealer test the cap and check for leaks in
the cooling system.
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Page 449 of 620

4476-3. Do-it-yourself maintenance
6
Maintenance and care
LS600hL_U(OM50E41U)
Check the radiator and condenser and clear away any foreign objects.
If either of the above parts is extremely dirty or you are not sure of their
condition, have your vehicle inspected by your Lexus dealer.
CAUTION
■When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps.(P. 5 3 4 )
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing serious injuries, such as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor straight antifreeze. The correct mixture of water
and antifreeze must be used to provide proper lubrication, corrosion protection
and cooling. Be sure to read the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to prevent it from damaging parts or paint.
Radiator and condenser
CAUTION
■When the hybrid system is hot
Do not touch the radiator or condenser as they may be hot and cause serious inju-
ries, such as burns.
Page 494 of 620
4927-2. Steps to take in an emergency
LS600hL_U(OM50E41U)●
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 think something is wrong
If you notice any of the following symptoms, your vehicle probably
needs adjustment or repair. Contact your Lexus dealer as soon as pos-
sible.
Visible symptoms
Audible symptoms
Operational symptoms
Page 507 of 620

5057-2. Steps to take in an emergency
7
When trouble arises
LS600hL_U(OM50E41U)
■The LKA (Lane-Keeping Assist) lane departure warning function (if equipped)
In the following cases, the warning message will not be displayed even if a lane line is
crossed.
●When the vehicle speed deviates from the operating range of the LKA system
functions
●When the lane lines cannot be recognized
●When the steering wheel is turned as far as necessary to cause the vehicle to
change lanes
■System warning lights
The master warning light does not come on or flash in the following cases. Instead, a
separate system warning light will come on or flash along with the message shown
on the multi-information display.
●Malfunction of the brake system
The brake system warning light (red indicator) comes on. ( P. 4 9 3 )
●Malfunction of the regenerative brake syst em, electronically controlled brake sys-
tem or electric parking brake
The brake system warning light (yellow indicator) comes on. ( P. 495)
●Malfunction of the ABS
The ABS warning light comes on. ( P. 4 9 4 )
●Malfunction of the charging system
The charging system warning light comes on. ( P. 4 9 4 )
●Indicates that a door or the trunk is not fully closed
The open door warnin g light comes on. (P. 4 9 6 )
●High engine coolant temperature
The needle of the engine coolant temperature gauge enters the red zone.
( P. 5 3 0 )
■If “Maintenance required ” is shown (U.S.A. only)
Perform the necessary maintenance.
Please reset the message after the maintenance is performed. ( P. 4 2 6 )
■If “Hybrid System Overheat” is shown
Coping method: P. 5 3 0
This message may be displayed when driv ing under severe operating conditions.
(For example, when driving up a long steep hill.)
■Warning buzzer
In some cases, the buzzer may not be hear d due to ambient noise or sounds from the
audio system.
Page 532 of 620
5307-2. Steps to take in an emergency
LS600hL_U(OM50E41U)●
The needle of the engine
coolant temperature gauge ( P. 99) enters
the red zone or a loss of hybrid system power is experienced. (For
example, the vehicle speed does not increase.)
●“Hybrid System Overheat” is shown on the multi-information display.
●Steam comes out from under the hood.
■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, and then stop the hybrid system.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the hybrid system has
cooled down sufficiently,
inspect the hoses and radiator
core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant
leaks, immediately contact your
Lexus dealer.
If your vehicle overheats
The following may indicate that your vehicle is overheating.
Correction procedures
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Page 533 of 620
5317-2. Steps to take in an emergency
7
When trouble arises
LS600hL_U(OM50E41U)
The coolant level is satisfactory
if it is between the “FULL” and
“LOW” lines on the reservoir.Reservoir
“FULL”
“LOW”
Add coolant if necessary.
( P. 440)
Water can be used in an emer-
gency if coolant is unavailable.
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Page 534 of 620

5327-2. Steps to take in an emergency
LS600hL_U(OM50E41U)
Start the hybrid system and turn the air conditioning system on to
check that the radiator cooling fan operates and to check for coolant
leaks from the radiator or hoses.
The fan operates when the air conditioning system is turned on immediately
after a cold start. Confirm that the fan is operating by checking the fan sound
and air flow. If it is difficult to check these, turn the air conditioning system on
and off repeatedly.
(The fan may not operate in freezing temperatures.)
If the fan is not operating:
Stop the hybrid system immediately and contact your Lexus dealer.
If the fan is operating:
Have the vehicle inspected at the nearest Lexus dealer.
■If “Hybrid System Overheat” is shown on the multi-information dis-
play
Stop the vehicle in a safe place.
Stop the hybrid system and carefully lift the hood.
After the hybrid system has
cooled down, inspect the
hoses and radiator core (radia-
tor) for any leaks.Radiator
Cooling fans
If a large amount of coolant
leaks, immediately contact your
Lexus dealer.
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Page 535 of 620
5337-2. Steps to take in an emergency
7
When trouble arises
LS600hL_U(OM50E41U)
The coolant level is satisfactory
if it is between the “F” and “L”
lines on the reservoir.Reservoir
“F”
“L”
Add coolant if necessary.
( P. 440)
Water can be used in an emer-
gency if coolant is unavailable.
Start the hybrid system and check fo r the multi-information display.
If the message does not disappear:
Stop the hybrid system and contact your Lexus dealer.
If the message is not displayed:
Have the vehicle inspected at the nearest Lexus dealer.
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