Page 656 of 860
656 4-3. Do-it-yourself maintenance
SIENNA_U (OM45477U)
2GR-FE engine
Washer fluid tank (P. 671)
Engine oil filler cap ( P. 659)
Engine oil level dipstick ( P. 657)
Engine coolant reservoir ( P. 662)Brake fluid reservoir
( P. 665)
Fuse box ( P. 696)
Battery ( P. 667)
Electric cooling fans
Condenser ( P. 664)
Radiator ( P. 664)
Page 662 of 860

662 4-3. Do-it-yourself maintenance
SIENNA_U (OM45477U)
Engine coolantThe coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir when the engine is cold.
Reservoir cap
“FULL”
“LOW”
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line.
■Coolant selection
Only use “Toyota Super Long Life Coolant” or 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 [-35 C])
Canada: “Toyota Super Long Life Coolant” is a mixture of 55 % coolant and 45 % deionized water.
(Minimum temperature: -44 F [-42 C])
For more details about engine coolant, contact your Toyota dealer.
■ If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine coolant reservoir caps drain cock
and water pump.
If you cannot find a leak, have your Toyota dealer test the cap and check for
leaks in the cooling system.
Page 663 of 860
663
4-3. Do-it-yourself maintenance
4
Maintenance and care
SIENNA_U (OM45477U)
CAUTION
■
When the engine is hot
Do not remove the engine coolant reservoir cap.
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 stra ight 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.
Page 664 of 860

664 4-3. Do-it-yourself maintenance
SIENNA_U (OM45477U)
Radiator and condenserCheck the radiator and condenser and clear away any foreign
objects.
If either of the above parts is extr emely dirty or you are not sure of
their condition, have your vehicle inspected by your Toyota dealer.
CAUTION
■When the engine is hot
Do not touch the radiator or condenser as they may be hot and cause seri-
ous injuries, such as burns.
■ When the electric cooling fan is operating
Do not touch the engine compartment.
Vehicles without a smart key system: With the engine switch in the “ON”
position, the electric cooling fans may automatically start to run if the air con-
ditioning is on and/or the coolant temperature is high. Be sure the engine
switch is in the “LOCK” position when working near the electric cooling fan or
radiator grille.
Vehicles with a smart key system: With the “ENGINE START STOP” switch
in IGNITION ON mode, the electric cooling fans may automatically start to
run if the air conditioning is on and/or the coolant temperature is high. Be
sure the “ENGINE START STOP” switch is OFF when working near the elec-
tric cooling fans or radiator grille.
Page 727 of 860
5
When trouble arises
727
5-1. Essential information
SIENNA_U (OM45477U)
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably
needs adjustment or repair. Contact your Toyota dealer as soon as
possible.
■ Visible symptoms
●Fluid leaks under the vehicle
(Water dripping from the air cond itioning after use is normal.)
● Flat-looking tires or uneven tire wear
● Engine coolant temperature g auge needle continually points
higher than normal
■ Audible symptoms
●Changes in exhaust sound
● Excessive tire squeal when cornering
● Strange noises related to the suspension system
● Pinging or other noises related to the engine
■ Operational symptoms
●Engine missing, stumbling or running rough
● 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, s pongy feeling, pedal almost
touches the floor
Page 775 of 860
5
When trouble arises
775
5-2. Steps to take in an emergency
SIENNA_U (OM45477U)
If your vehicle overheats
If your engine overheats:
Stop the vehicle in a safe place and turn off the air condi-
tioning system.
Check to see if steam is coming out from under the hood.
If you see steam: Stop the engine. Carefully lift the hood after the steam
subsides and then restart the engine.
If you do not see steam: Leave the engine running and carefully lift the hood.
Check to see if the cooling fans are operating.
If the fans are operating: Wait until the temperature of the engine (shown on the
instrument cluster) begins to fall and then stop the
engine.
If the fans are not operating: Stop the engine immediately and call your Toyota dealer.
After the engine has cooled
down sufficiently, check the
engine coolant level and
inspect the radiator core (radi-
ator) for any leaks.STEP1
STEP2
STEP3
STEP5STEP4
Page 776 of 860
776 5-2. Steps to take in an emergency
SIENNA_U (OM45477U)
■Overheating
If you observe the following, your vehicle may be overheating:
● The engine coolant temperature gauge enters the red zone or a loss of
power is experienced.
● Steam comes out from under the hood.
Add engine coolant if neces-
sary.
Water can be used in an emer-
gency if engine coolant is
unavailable.
(P. 790)
Have the vehicle inspected at the nearest Toyota dealer as soon as
possible.
STEP5
Page 777 of 860
5
When trouble arises
777
5-2. Steps to take in an emergency
SIENNA_U (OM45477U)
CAUTION
■
To prevent an accident or injury when inspecting under the hood of
your vehicle
● If steam is seen coming from under the hood, do not open the hood until
the steam has subsided. The engine compartment may be very hot, caus-
ing serious injuries such as burns.
● Keep hands and clothing away from the fans and drive belt while the
engine is running.
● Do not loosen the coolant reservoir cap while the engine and radiator are
hot.
Serious injury, such as burns, may result from hot coolant and steam
released under pressure.
NOTICE
■When adding engine coolant
Wait until the engine has cooled down before adding engine coolant.
When adding coolant, do so slowly. Adding cool coolant to a hot engine too
quickly can cause damage to the engine.