2012 TOYOTA SIENNA coolant temperature

244
SIENNA_U (OM45477U)
2-2. Instrument cluster and information display
Gauges and meters
Tachometer
Displays the engine speed in revolutions per minute.
Speedometer
Displays the vehicle speed.
Fuel gauge
Displays the quantity of fuel remaining in the tank.
Engine coolant temperature gauge
Displays the engine coolant temperature.
Odometer and trip meter display
Odometer: Displays the total distance the vehicle has been driven.
Trip meter: Displays the distance the vehicle has been driven since themeter was last reset. Trip meters “A” and “B” can be used to
record and display different distances independently.
Odometer/trip meter display change button
P. 245

246 2-2. Instrument cluster and information display
SIENNA_U (OM45477U)
■The meters and display illuminate when (Optitron type meters)
Vehicles without a smart key system:
The engine switch is in the “ON” position.
Vehicles with a smart key system:
The “ENGINE START STOP” switch is in IGNITION ON mode.
NOTICE
■To prevent damage to the engine and its components
● Do not let the indicator needle of the tachometer enter the red zone, which
indicates 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. 775)

368 2-5. Driving information
SIENNA_U (OM45477U)●
Take care when passing other v ehicles. Passing requires consider-
able distance. After passing a vehi cle, do not forget the length of
your trailer, and be sure you hav e plenty of room before changing
lanes.
● To maintain engine braking efficiency and charging system perfor-
mance when using engine braking, do not put the transmission in
D.
Transmission shift range position must be in 4 in the S mode.
● Instability happens more frequently when descending steep or long
downhill grades. Before descending, slow down and downshift. Do
not make sudden downshifts while descending steep or long down-
hill grades.
● Avoid holding the brake pedal down too long or applying the
brakes too frequently. This could cause the brakes to overheat and
result in reduced braking efficiency.
● Due to the added load of the trailer, your vehicle’s engine may
overheat on hot days (at temper atures over 85°F [30°C]) when
driving up a long or steep grade. If the Engine coolant temperature
gauge overheating, immediately turn off the air conditioning (if in
use), pull your vehicle off the road and stop in a safe spot.
(  P. 775)

649
4-3. Do-it-yourself maintenance
4
Maintenance and care
SIENNA_U (OM45477U)
CAUTION
The engine compartment contains many mechanisms and fluids that may
move suddenly, become hot, or become electrically energized. To avoid death
or serious injury, observe the following precautions:
■
When working on the engine compartment:
● Keep hands, clothing and tools away from the moving fan and engine
drive belt.
● Be careful not to touch the engine, radiator, exhaust manifold, etc. right
after driving as they may be hot. Oil and other fluids may also be hot.
● Do not leave anything that may burn easily, such as paper and rags, in the
engine compartment.
● Do not smoke, cause sparks or expose an open flame to fuel or the bat-
tery. Fuel and battery fumes are flammable.
● Be extremely cautious when working on the battery. It contains poisonous
and corrosive sulfuric acid.
■ When working near the electric c ooling fans or radiator grille
Vehicles without a smart key system: Be sure the engine switch is off. With
the engine switch in the “ON” position, the electric cooling fans may auto-
matically start to run if the air conditioning is on and/or the coolant tempera-
ture is high. ( P. 664)
Vehicles with a smart key system: Be sure the “ENGINE START STOP”
switch is off. With the “ENGINE START STOP” switch in IGNITION ON
mode, the electric cooling fans may automatically start to run if the air condi-
tioning is on and/or the coolant temperature is high. ( P. 664)

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.

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.

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

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
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