Page 453 of 628
4397-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53B95E)
12-volt battery
P. 447
Engine compartment
Power control unit coolant res-
ervoir (P. 444)
Engine oil level dipstick
(P. 440)
Engine coolant reservoir
(P. 444)
Engine oil filler cap
(P. 441)Fuse box (P. 475)
Washer fluid tank (P. 446)
Electric cooling fans
Condenser (P. 446)
Power control unit coolant
radiator (P. 446)
Engine coolant radiator
(P. 446)1
2
3
4
5
6
7
8
9
10
Page 454 of 628
4407-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
With the engine at operating temperature and turned off, check the oil
level on the dipstick.
Checking the engine oil
Park the vehicle on level ground. After warming up the engine and
turning off the hybrid system, wait more than 5 minutes for the oil to
drain back into the bottom of the engine.
Holding a rag under the end,
pull the dipstick out.
Wipe the dipstick clean.
Reinsert the dipstick fully.
Holding a rag under the end,
pull the dipstick out and check
the oil level.
Low
Normal
Excessive
The shape of the dipstick may
differ depending on the type of
vehicle or engine.
Wipe the dipstick and reinsert it fully.
Engine oil
1
2
3
4
5
1
2
3
6
Page 455 of 628
4417-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53B95E)
Adding engine oil
If the oil level is below or near
the low level mark, add engine
oil of the same type as that
already in the engine.
Make sure to check the oil type and prepare the items needed before
adding oil.
Remove the oil filler cap by turning it counterclockwise.
Add engine oil slowly, checking the dipstick.
Install the oil filler cap by turning it clockwise.
Engine oil selectionP. 5 6 5
Oil quantity (Low Full) 1.5 L (1.6 qt., 1.3 Imp. qt.)
Items Clean funnel
1
2
3
Page 456 of 628

4427-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
Engine oil consumption
A certain amount of engine oil will be consumed while driving. In the following
situations, oil consumption may increase, and engine oil may need to be refilled
in between oil maintenance intervals.
When the engine is new, for example directly after purchasing the vehicle or
after replacing the engine
If low quality oil or oil of an inappropriate viscosity is used
When driving at high engine speeds or with a heavy load, when towing, or
when driving while accelerating or decelerating frequently
When leaving the engine idling for a long time, or when driving frequently
through heavy traffic
After changing the engine oil (if equipped)
The engine oil maintenance data should be reset. Perform the following proce-
dures:
While the hybrid system is operating, switch the multi-information display to
the “Settings” screen. (P. 118)
Select “Maintenance System” on the “Settings” screen.
Select “Yes” on the “Maintenance System” screen.
A message will be displayed when the
reset procedure has been completed.
1
2
3
Page 457 of 628

4437-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53B95E)
CAUTION
Used engine oil
Used engine oil contains potentially harmful contaminants which may cause
skin disorders such as inflammation and skin cancer, so care should be taken
to avoid prolonged and repeated contact. To remove used engine oil from
your skin, wash thoroughly with soap and water.
Dispose of used oil and filters only in a safe and acceptable manner. Do not
dispose of used oil and filters in household trash, in sewers or onto the
ground.
Call any authorized Lexus dealer or repairer, or another duly qualified and
equipped professional, service station or auto parts store for information con-
cerning recycling or disposal.
Do not leave used engine oil within the reach of children.
NOTICE
To prevent serious engine damage
Check the oil level on a regular basis.
When replacing the engine oil
Be careful not to spill engine oil on the vehicle components.
Avoid overfilling, or the engine could be damaged.
Check the oil level on the dipstick every time you refill the vehicle.
Be sure the engine oil filler cap is properly tightened.
Page 458 of 628
4447-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
Engine coolant reservoir
The coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir when the hybrid system is cold.
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, add coolant up to
the “FULL” line. (P. 555)
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. 555)
Coolant
1
2
3
1
2
3
Page 459 of 628

4457-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53B95E)
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.
“Toyota Super Long Life Coolant” is a mixture of 50% coolant and 50% deion-
ized water. (Minimum temperature: -35C [-31F])
For more details about coolant, contact any authorized Lexus dealer or repairer,
or another duly qualified and equipped professional.
If the coolant level drops within a short time of replenishing
Visually check the radiators, hoses, engine/power control unit coolant reservoir
caps, drain cock and water pump.
If you cannot find a leak, have any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional, test the cap and check for leaks
in the cooling system.
CAUTION
When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps or water
filler cap. (P. 558)
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 pro-
tection 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.
Page 460 of 628

4467-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
Check the radiators 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 any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
If any washer does not work or the
warning message appears on the
multi-information display, the
washer tank may be empty. Add
washer fluid.
Radiators and condenser
CAUTION
When the hybrid system is hot
Do not touch the radiators or condenser as they may be hot and cause serious
injuries, such as burns.
Washer fluid
CAUTION
When adding washer fluid
Do not add washer fluid when the hybrid system is hot or operating as washer
fluid contains alcohol and may catch fire if spilled on the engine etc.
NOTICE
Do not use any fluid other than washer fluid
Do not use soapy water or engine antifreeze instead of washer fluid.
Doing so may cause streaking on the vehicle’s painted surfaces.
Diluting washer fluid
Dilute washer fluid with water as necessary.
Refer to the freezing temperatures listed on the label of the washer fluid bottle.