2012 TOYOTA SIENNA overheating

223
2-1. Driving procedures
2
When driving
SIENNA_U (OM45477U)
CAUTION
■
When taking a nap in the vehicle
Always turn the engine off. Otherwise, if you accidentally move the shift lever
or depress the accelerator pedal, this could cause an accident or fire due to
engine overheating. Additionally, if the vehicle is parked in a poorly venti-
lated area, exhaust gases may collect and enter the vehicle, leading to
death or a serious health hazard.
■ When braking
● When the brakes are wet, drive more cautiously.
Braking distance increases when the brakes are wet, and this may cause
one side of the vehicle to brake differently than the other side. Also the
parking brake may not securely hold the vehicle.
● If the power brake assist function does not operate, do not follow other
vehicles closely and avoid hills or sharp turns that require braking.
In this case, braking is still possible, but the brake pedal should be
depressed more firmly than usual. Also, the braking distance will increase.
● Do not pump the brake pedal if the engine stalls.
Each push on the brake pedal uses up the reserve for the power-assisted
brakes.
● The brake system consists of 2 individual hydraulic systems: If one of the
systems fails, the other will still operate. In this case, the brake pedal
should be depressed more firmly than usual and braking distance will
increase.
If this happens, do not continue to drive the vehicle. Have your brakes
fixed immediately.
■ If the vehicle becomes stuck (AWD models)
Do not spin the wheels excessively when any of the tires is up in the air, or
the vehicle is stuck in sand or mud, etc. This may damage the driveline com-
ponents or unexpectedly propel the vehicle forward or backward, causing an
accident.

233
2-1. Driving procedures
2
When driving
SIENNA_U (OM45477U)
■
Electronic key battery depletion
 P. 5 0
■ Conditions aff ecting operation
 P. 4 6
■ Note for the entry function
 P. 4 7
■ If the engine does not start
The engine immobilizer system may not have been deactivated. ( P. 159)
■ Steering lock
After turning the “ENGINE START STOP” switch off and opening and closing
the doors, the steering wheel will be locked due to the steering lock function.
Operating the “ENGINE START STOP” switch again automatically cancels
the steering lock.
■ When the steering lock cannot be released
■ Steering lock motor overheating prevention
To prevent the steering lock motor from overheating, the motor may be sus-
pended if the engine is turned on and off repeatedly in a short period of time.
In this case, refrain from operating the engine. After about 10 seconds, the
steering lock motor will resume functioning.
The green indicator light on the “ENGINE
START STOP” switch will flash and a
message will be shown on the multi-infor-
mation display. Press the “ENGINE
START STOP” switch while turning the
steering wheel left and right.

242
2-1. Driving procedures
SIENNA_U (OM45477U)
Parking brake
■Usage in winter time
See “Winter driving tips” for parking brake usage in winter time. ( P. 352)
NOTICE
■Before driving
Fully release the parking brake.
Driving the vehicle with the parking brake set will lead to brake components
overheating, which may affect braking performance and increase brake
wear.
To set the parking brake, fully
depress the parking brake
pedal with your left foot while
depressing the brake pedal
with your right foot.
(Depressing the pedal again
releases the parking brake.)
U.S.A. Canada

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)

331
2-4. Using other
driving systems
2
When driving
SIENNA_U (OM45477U)
■Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from
overheating when there is frequent steering input over an extended period of
time. The steering wheel may feel heavy as a result. Should this occur,
refrain from excessive steering input or stop the vehicle and turn the engine
off. The EPS system should return to normal within 10 minutes.
CAUTION
■ABS does not operate effectively when
● Tires with inadequate gripping ability are used (such as excessively worn
tires on a snow covered road).
● The vehicle hydroplanes while driving at high speed on wet or slick roads.
■ Stopping distance when ABS is oper ating may exceed that of normal
conditions
The ABS is not designed to shorten the vehicle’s stopping distance. Always
maintain a safe distance from the vehicle in front of you in the following situ-
ations.
● When driving on dirt, gravel or snow-covered roads
● When driving with tire chains
● When driving over bumps in the road
● When driving over roads with potholes or roads with uneven surfaces
■ TRAC may not operate effectively when
Directional control and power may not be achievable while driving on slip-
pery road surfaces, even if the TRAC system is operating.
Do not drive the vehicle in conditions where stability and power may be lost.

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)

599
3-8. Other interior features
3
Interior features
SIENNA_U (OM45477U)
CAUTION
■
Burns
● Use caution when seating the following persons in a seat with the seat
heater on to avoid the possibility of burns:
• Babies, small children, the elderly, the sick and the physically chal-
lenged
• Persons with sensitive skin
• Persons who are fatigued
• Persons who have taken alcohol or drugs that induce sleep (sleeping drugs, cold remedies, etc.)
● Do not cover the seat with anything when using the seat heater.
Using the seat heater with a blanket or cushion increases the temperature
of the seat and may lead to overheating.
● Do not use the seat heater more than necessary. Doing so may cause
minor burns or overheating.
NOTICE
■To prevent seat heater damage
Do not put heavy objects that have an uneven surface on the seat and do
not stick sharp objects (needles, nails, etc.) into the seat.
■ To prevent battery discharge
Turn the seat heaters off when the engine is not running.

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