
SIENNA_OM_OM08007U_(U)
3014-5. Using the driving support systems
4
Driving
WARNING
■TRAC may not operat e effectively when
Directional  control  and  power  may  not  be  achievable  while  driving  on  slip-
pery road surfaces, even if the TRAC system is operating.
Drive  the  vehicle  carefully  in  conditions  where  stability  and  power  may  be
lost.
■ Hill-start assist control (vehicles with a hill-start assist control system)
●Do  not  overly  rely  on  hill-start  assist  control.  Hill-start  assist  control  may
not operate effectively on steep inclines and roads covered with ice.
● Unlike the parking brake, hill-start assist control is not intended to hold the
vehicle  stationary  for  an  extended  period  of  time.  Do  not  attempt  to  use
hill-start  assist  control  to  hold  the  vehicle  on  an  incline,  as  doing  so  may
lead to an accident.
■ When the VSC is activated
The slip indicator light flashes. Always drive carefully. Reckless driving may
cause an accident. Exercise particular care when the indicator light flashes.
■ When the TRAC/VSC syst ems are turned off
Be  especially  careful  and  drive  at  a  speed  appropriate  to  the  road  condi-
tions.  As  these  are  the  systems  to  help  ensure  vehicle  stability  and  driving
force, do not turn the TRAC/VSC systems off unless necessary.
■
Replacing tires
Make  sure  that  all  tires  are  of  the  specified  size,  brand,  tread  pattern
and total load capacity. In addition, make sure that the tires are inflated
to the recommended tire inflation pressure level.
The ABS, TRAC and VSC systems will not  function correctly if different
tires are installed on the vehicle.
Contact  your  Toyota  dealer  for  further  information  when  replacing  tires
or wheels.
■Handling of tires and suspension
Using  tires  with  any  kind  of  problem  or  modifying  the  suspension  will
affect the driving assist systems,  and may cause the system to malfunc-
tion.
■ Active Torque Control 4WD system (AWD models only)
●The  AWD  system  of  this  vehicle  is  intended  to  ensure  driving  stability  on
normal  roads.  It  is  not  designed  for  use  in  demanding  situations  such  as
rally driving.
● Take care when driving on slippery road surfaces. 

318
SIENNA_OM_OM08007U_(U)
4-6. Driving tips
Accelerate the vehicle slowly, keep a safe distance between you and
the vehicle ahead, and drive at a reduced speed suitable to road con-
ditions.
●Park  the  vehicle  and  move  the  shift  lever  to  P  without  setting  the
parking brake. The parking brake may freeze up, preventing it from
being  released.  If  the  vehicle  is  parked  without  setting  the  parking
brake, make sure block the wheels.
Failure to do so may be dangerous  because it may cause the vehi-
cle to move unexpectedly, pos sibly leading to an accident.
● If  the  vehicle  is  parked  without  setting  the  parking  brake,  confirm
that the shift lever cannot be moved out of P
*.
*: The  shift  lever  will  be  locked  if  it  is  attempted  to  be  shifted  from  P  to  any
other position without depressing the brake pedal. If the shift lever can be
shifted from P, there may be a problem with the shift lock system. Have the
vehicle inspected by your Toyota dealer immediately.
Use the tire chains of correct size and type.
Use  SAE  Class  “S”  type  radial  tire  chains,  with  the  exception  of  radial
cable chains or V-bar type chains.
Regulations  regarding  the  use  of  tire  chains  vary  depending  on  loca-
tion and type of road. Al ways check local regulations before installing
chains.
■ Tire chain installation
Observe the following precautions when installing and removing chains.
●Install and remove tire chains in a safe location.
● Install tire chains on the front tires only. Do not install tire chains on the rear
tires.
● Install tire chains on front tires as tightly as possible. Retighten chains after
driving 1/4 - 1/2 mile (0.5 - 1.0 km).
● Install tire chains following the instructions provided with the tire chains.
When driving the vehicle
When parking the vehicle
Selecting tire chains
Regulations on the use of tire chains 

SIENNA_OM_OM08007U_(U)
3194-6. Driving tips
4
Driving
WARNING
■Driving with snow tires
Observe the following precautions to reduce the risk of accidents.
Failing  to  do  so  may  result  in  a  loss  of  vehicle  control  and  cause  death  or
serious injury.
●Use tires of the specified size.
● Maintain the recommended level of air pressure.
● Do  not  drive  in  excess  of  75  mph  (120  km/h),  regardless  of  the  type  of
snow tires being used.
● Use snow tires on all, not just some wheels.
■ Driving with tire chains
Observe the following precautions to reduce the risk of accidents.
Failing  to  do  so  may  result  in  the  vehicle  being  unable  to  be  driven  safely,
and may cause death or serious injury.
●Do not drive in excess of the speed limit specified for the tire chains being
used or 30 mph (50 km/h), whichever is lower.
● Avoid driving on bumpy road surfaces or over potholes.
● Avoid  sudden  acceleration,  abrupt  steering,  sudden  braking  and  shifting
operations that cause sudden engine braking.
● Slow down sufficiently before entering a curve to ensure that vehicle con-
trol is maintained.
NOTICE
■Repairing or replacing snow tires
Request  repairs  or  replacement  of  snow   tires  from  Toyota  dealers  or  legiti-
mate tire retailers.
This is because the removal and attachment of snow tires affects the opera-
tion of the tire pressure warning valves and transmitters.
■ Fitting tire chains
The tire pressure warning valves and transmitters may not function correctly
when tire chains are fitted. 

SIENNA_OM_OM08007U_(U)
4977-3. Do-it-yourself maintenance
7
Maintenance and care
Your vehicle is equipped with a tire pressure warning system that uses
tire  pressure  warning  valves  and  tr ansmitters  to  detect  low  tire  infla-
tion pressure before serious problems arise. ( P. 547)
Vehicles  with  compact  spare  tire :  The  compact  spare  tire  is  not
equipped with the tire pressure warning valve and transmitters.
◆Installing tire pressure warning valves and transmitters
When  replacing  tires  or  wheels,  tire  pressure  warning  valves  and
transmitters must also be installed.
When  new  tire  pressure  warning  valves  and  transmitters  are
installed,  new  ID  codes  must  be  registered  in  the  tire  pressure
warning  computer  and  the  tire  pr essure  warning  system  must  be
initialized.  Have  tire  pressure  warning  valve  and  transmitter  ID
codes registered by your Toyota dealer. ( P. 498)
◆Initializing the tire pressure warning system
When  the  tire  size  is  changed,  the  tire  pressure  warning  system
must be initialized.
When the tire pressure warning system is initialized,  the current tire
inflation pressure is set as the benchmark pressure.
■How to initialize the tire pressure warning system
Park the vehicle in a safe place and turn the engine switch off.
Initialization cannot  be performed while the vehicle is moving.
Adjust the tire inflation pressure to  the specified cold tire inflation
pressure level. ( P. 606)
Make  sure  to  adjust  the  tire  pressu re  to  the  specified  cold  tire infla-
tion  pressure  level.  The  tire  pressure  warning  system  will  operate
based on this pressure level.
Turn  the  engine  switch  to  the  “ON”  position  (vehicles  without  a
smart key system) or IGNITION ON mode (vehicles with a smart
key system).
Tire pressure warning system
1
2
3 

SIENNA_OM_OM08007U_(U)
4997-3. Do-it-yourself maintenance
7
Maintenance and care
■When to replace your vehicle’s tires
Tires should be replaced if:
●The treadwear indicators are showing on a tire.
●You  have  tire  damage  such  as  cuts,  splits,  cracks  deep  enough  to
expose the fabric, and bulges indicating internal damage
●A tire goes flat repeatedly or cannot be properly repaired due to the size
or location of a cut or other damage
If you are not sure, consult with your Toyota dealer.
■Replacing tires and wheels
If the ID code of the tire pressure warning valve and transmitter is not reg-
istered, the tire  pressure warning system will not work properly. After driv-
ing  for  about  20  minutes,  the  tire  pressure  warning  light  blinks  for
1 minute and stays on to indicate a system malfunction.
■Tire life
Any tire over 6 years old must be checked by a qualified technician even
if it has seldom or never been used or damage is not obvious.
■Routine tire inflation pressure checks
The  tire  pressure  warning  system  does  not  replace  routine  tire  inflation
pressure  checks.  Make  sure  to  check  tire  inflation  pressure  as  part  of
your routine of daily vehicle checks.
■Maximum load of tire
Check that the number given by dividing the maximum load by 1.10 of the
replacement  tire  is  greater  than  1/ 2  of  the  Gross  Axle  Weight  Ratings
(GAWR) of either the front axle or the rear axle, whichever is greater.
For  the  GAWR,  see  the  Certification
Label. For the maximum load of the tire,
see  the  load  limit  at  maximum  cold  tire
inflation  pressure  mentioned  on  the
sidewall of the tire. ( P. 612) 

500
SIENNA_OM_OM08007U_(U)
7-3. Do-it-yourself maintenance
■Tire types
●Summer tires
Summer tires are high-speed performance tires best suited to highway
driving under dry conditions. Since summer tires do not have the same
traction  performance  as  snow  tires,  summer  tires  are  inadequate  for
driving  on  snow-covered  or  icy  ro ads.  For  driving  on  snow-covered
roads or icy roads, the use of snow tires is recommended. When install-
ing snow tires, be sure  to replace all four tires.
●All season tires
All  season  tires  are  designed  to  provide  better  traction  in  snow  and  to
be  adequate  for  driving  in  most  winter  conditions,  as  well  as  for  use
year  round.  All  season  tires,  however,  do  not  have  adequate  traction
performance compared with snow tires in heavy or loose snow. Also, all
season  tires  fall  short  in  acceleration  and  handling  performance  com-
pared with summer tires in highway driving.
●Snow tires
For  driving  on  snow-covered  roads  or  icy  roads,  we  recommend  using
snow  tires.  If  you  need  snow  tires,  select  tires  of  the  same  size,  con-
struction  and  load  capacity  as  the  or iginally  installed  tires.  Since  your
vehicle  has  radial  tires  as  original  equipment,  make  sure  your  snow
tires  also  have  radial  construction.  Do  not  install  studded  tires  without
first  checking  local  regulations  for  possible  restriction.  Snow  tires
should be installed on all wheels. ( P. 317)
■If the tread on snow tires wears down below 0.16 in. (4 mm)
The effectiveness of the tire s as snow tires is lost. 

507
SIENNA_OM_OM08007U_(U)
7-3. Do-it-yourself maintenance
7
Maintenance and care
Wheels
When replacing wheels, care should be taken to ensure that they are
equivalent to those removed in load capacity, diameter, rim width and
inset
*.
Replacement wheels are available at your Toyota dealer.
*: Conventionally referred to as “offset”.
Toyota does not recommend using the following:
● Wheels of different sizes or types
● Used wheels
● Bent wheels that have been straightened
● Use  only  Toyota  wheel  nuts  and  wrenches  designed  for  use  with
your aluminum wheels.
● When  rotating,  repairing  or  changi ng  your  tires,  check  that  the
wheel nuts are still tight after  driving 1000 miles (1600 km).
● Be  careful  not  to  damage  the  aluminum  wheels  when  using  tire
chains.
● Use only Toyota genuine balance weights or equivalent and a plas-
tic or rubber hammer when balancing your wheels.
■When replacing wheels
The  wheels  of  your  vehicle  are  equipped  with  tire  pressure  warning
valves  and  transmitters  that  allow  the  tire  pressure  warning  system  to
provide advanced warning in the event of a loss in tire inflation pressure.
Whenever  wheels  are  replaced,  tire  pressure  warning  valves  and  trans-
mitters must be installed. ( P. 497)
If a wheel is bent, cracked or  heavily corroded, it should be
replaced.
Otherwise, the tire may separate from the wheel or cause a loss
of handling control.
Wheel selection
Aluminum wheel precautions 

508
SIENNA_OM_OM08007U_(U)
7-3. Do-it-yourself maintenance
WARNING
■When replacing wheels
●Do not use wheels that are a different size from those recommended in
the Owner’s Manual, as this may result in a loss of handling control.
●Never  use  an  inner  tube  in  a  leaking  wheel  which  is  designed  for  a
tubeless tire. Doing so may result in an accident, causing death or seri-
ous injury.
■When installing the wheel nuts
●Never use oil or grease on the wheel bolts or wheel nuts.
Oil and grease may cause the wheel  nuts to be excessively tightened,
leading to bolt or disc wheel damage. In addition, the oil or grease can
cause the wheel nuts to loosen and the wheel may fall off, causing an
accident  and  resulting  in  death  or  serious  injury.  Remove  any  oil  or
grease from the wheel bolts or wheel nuts.
■Use of defective wheels prohibited
Do not use cracked or deformed wheels.
Doing so could cause the tire to leak air during driving, possibly causing
an accident.
NOTICE
■Replacing tire pressure warning valves and transmitters
●Because  tire  repair  or  replacement  may  affect  the  tire  pressure  warn-
ing  valves  and  transmitters,  make  sure  to  have  tires  serviced  by  your
Toyota dealer or other qualified service shop. In addition, make sure to
purchase  your  tire  pressure  warning  valves  and  transmitters  at  your
Toyota dealer.
●Ensure that only genuine Toyota wheels are used on your vehicle.
Tire  pressure  warning  valves  and  transmitters  may  not  work  properly
with non-genuine wheels. 
●Be  sure  to  install  the  wheel  nuts  with
the  tapered  ends  facing  inward.
Installing  the  nuts  with  the  tapered
ends  facing  outward  can  cause  the
wheel  to  break  and  eventually  cause
the  wheel  to  come  off  while  driving,
which  could  lead  to  an  accident
resulting in death or serious injury.Tapered 
portion