Page 310 of 860

310 2-4. Using other driving systems
SIENNA_U (OM45477U)
CAUTION
■Before using dynamic radar cruise control
Do not overly rely on vehicle-to-vehicle distance control.
Be aware of the set speed. If automatic deceleration/acceleration is not
appropriate, adjust the vehicle speed, as well as the distance between your
vehicle and vehicles ahead by applying the brakes, etc.
■ Caution regarding the driving assist systems
Observe the following precautions.
Failure to do so may cause an accident resulting in death or serious injury.
● Assisting the driver to measure following distance
The dynamic radar cruise control is only intended to help the driver in
determining the following distance between the driver’s own vehicle and a
designated vehicle travelling ahead. It is not a mechanism that allows
careless or inattentive driving, and it is not a system that can assist the
driver in low-visibility conditions. It is still necessary for driver to pay close
attention to the vehicle’s surroundings.
● Assist the driver to judge proper following distance
The dynamic radar cruise control determines whether the following dis-
tance between the driver’s own vehicle and a designated vehicle travelling
ahead is appropriate or not. It is not capable of making any other type of
judgement. Therefore, it is absolutely necessary for the driver to remain
vigilant and to determine whether or not there is possibility of danger in
any given situation.
● Assisting the driver to operate the vehicle
The dynamic radar cruise control has no capability to prevent or avoid a
collision with a vehicle travelling ahead. Therefore, if there is ever a\
ny
danger, the driver must take immediate and direct control of the vehicle
and act appropriately in order to ensure the safety of all involved.
■ To avoid inadvertent cruise control activation
Switch the cruise control off using the “ON-OFF” button when not in use.
Page 311 of 860
311
2-4. Using other
driving systems
2
When driving
SIENNA_U (OM45477U)
CAUTION
■Situations unsuitable for dynamic radar cruise control
Do not use dynamic radar cruise control in any of the following situations.
Doing so may result in inappropriate speed control and could cause an acci-
dent resulting in death or serious injury.
● In heavy traffic
● On roads with sharp bends
● On winding roads
● On slippery roads, such as those covered with rain, ice or snow
● On steep downhills, or where there are sudden changes between sharp up
and down gradients
Vehicle speed may exceed the set speed when driving down a steep hill.
● At entrances to expressways
● When weather conditions are bad enough that they may prevent the sen-
sors from functioning correctly (fog, snow, sandstorm, heavy rain, etc.)
● When an approach warning buzzer is heard often
● When your vehicle is towing a trailer or during emergency towing
Page 313 of 860
313
2-4. Using other
driving systems
2
When driving
SIENNA_U (OM45477U)
CAUTION
■Handling the radar sensor
Observe the following to ensure the cruise control system can function effec-
tively:
Otherwise, the system may not function correctly and could result in an acci-
dent.
● Keep the sensor and grille cover clean at all times.
Clean the sensor and grille cover with a soft cloth so you do not mark or
damage them.
● Do not subject the sensor or surrounding area to a strong impact.
If the sensor moves even slightly off position, the system may malfunction.
If the sensor or surrounding area is subject to a strong impact, always
have the area inspected and adjusted by a Toyota dealer.
● Do not disassemble the sensor.
● Do not attach accessories or stickers to the sensor, grille cover or sur-
rounding area.
● Do not modify or paint the sensor and grille cover.
● Do not replace them with non-genuine parts.
Page 374 of 860

374 2-5. Driving information
SIENNA_U (OM45477U)
CAUTION
■To avoid accident or injury
● Do not use cruise control when towing.
● Slow down and downshift before descending steep or long downhill
grades. Do not make sudden downshifts while descending steep or long
downhill grades.
● Vehicle-trailer instability is more likely on steep long downhills. Before
descending steep or long downhill grades, slow down and downshift. Do
not make sudden downshifts when descending steep or long downhill
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.
● Do not tow a trailer when the compact spare tire is installed on your vehi-
cle.
■ Hitch
Trailer hitch assemblies have different weight capacities established by the
hitch manufacturer. Even though the vehicle may be physically capable of
towing a higher weight, the operator must determine the maximum weight
rating of the particular hitch assembly and never exceed the maximum
weight rating specified for the trailer-hitch. Exceeding the maximum weight
rating set by the trailer-hitch manufacturer can cause an accident resulting in
death or serious personal injuries.
Page 699 of 860
699
4-3. Do-it-yourself maintenance
4
Maintenance and care
SIENNA_U (OM45477U)
Fuse layout and amperage ratings
■ Engine compartment
FuseAmpereCircuit
1H-LP LVL
*17.5 A Headlight leveling system
2DSS1 7.5 A PCS (Pre-collision system),
dynamic radar cruise control sys-
tem
3 ST NO.2 7.5 A Starting system, multiport fuel
injection system/sequential multi-
port fuel injection system
4H-LP LH
*120 A Left-hand headlight (low beam)
5H-LP RH
*120 A Right-hand headlight (low beam)
Page 707 of 860

707
4-3. Do-it-yourself maintenance
4
Maintenance and care
SIENNA_U (OM45477U)
FuseAmpereCircuit
22 TAIL 10 A Tail lights, trailer lights (tail lights),
license plate light, rear combination
lights
23 WIP ECU 7.5 A Windshield wiper and rear window
wiper
24 P/VENT 15 A Power quarter windows
25 AFS 10 A Automatic High Beam
26 WIP 30 A Windshield wiper
27 WASHER 20 A Windshield washer
28 WIP RR 20 A Rear window wiper
29 WASHER RR 15 A Rear window washer
30 HTR-IG 10 A Air conditioning system
31 SHIFT LOCK 7.5 A Shift lock system, multiport fuel
injection system/sequential multi-
port fuel injection system
32 ECU-IG NO.2 10 A Pre-collision system, pre-collision
seat belt, dynamic radar cruise
control, electric power steering,
rain-sensing windshield wipers,
driving position memory system,
power sliding door, power third
seat, power back door, multiplex
communication system
33 PSD RH 25 A Power sliding door (right-side)
34 OBD 7.5 A On-board diagnosis system
35 S-HTR FL 15 A Seat heater (left-side)
36 S-HTR FR 15 A Seat heater (right-side)
Page 732 of 860
732 5-2. Steps to take in an emergency
SIENNA_U (OM45477U)
Warning lightWarning light/Details
(Flashes) Automatic High Beam indi
cator light (if equipped)
Indicates a malfunction in the Automatic High Beam sys-
tem ( P. 273)
(Flashes) Cruise control indicator
light (if equipped)
Indicates a malfunction in the cruise control system
( P. 293, 298)
(Flashes) Radar cruise control indicator light (if equipped)
Indicates a malfunction in the Dynamic radar cruise control
system ( P. 298)
Page 757 of 860

5
When trouble arises
757
5-2. Steps to take in an emergency
SIENNA_U (OM45477U)
CAUTION
■When using the compact spare tire
●Remember that the compact spare
tire provided is specifically
designed for use with your vehicle. Do not use your compact spare tire
on another vehicle.
●Do not use more than one compact spare tire simultaneously.
●Replace the compact spare tire with a standard tire as soon as possi-
ble.
●Avoid sudden acceleration, deceleration and braking, as well as sharp
cornering.
■When storing the compact spare tire
Be careful not to catch fingers or other body parts between the compact
spare tire and the body of the vehicle.
■When the compact spare tire is attached
The vehicle speed may not be correctly detected, and the following sys-
tems may not operate correctly:
●ABS & Brake assist
●Enhanced VSC
●TRAC
●Dynamic radar cruise control (if equipped)
●Cruise control (if equipped)
●PCS (if equipped)
●Navigation system (if equipped)
Also, not only can the following sys tem not be utilized fully, but it may
even negatively affect the drive-train components:
●AWD system (if equipped)