Page 227 of 860
227
2-1. Driving procedures
2
When driving
SIENNA_U (OM45477U)
■
Turning the key from “ACC” to “LOCK”
Shift the shift lever to P.
■ If the engine does not start (vehic les with engine immobilizer system)
The engine immobilizer system may not have been deactivated. ( P. 159)
■ When the steering lock cannot be released
■ Key reminder function
A buzzer sounds if the driver’s door is opened while the engine switch is in
the “LOCK” or “ACC” position to remind you to remove the key\
.
STEP1
Push in the key and turn it to the “LOCK”
position.STEP2
When starting the engine, the engine
switch may seem stuck in the “LOCK”
position. To free it, turn the key while turn-
ing the steering wheel slightly left and
right.
Page 233 of 860

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.
Page 243 of 860
243
2-1. Driving procedures
2
When driving
SIENNA_U (OM45477U)
Hor n
■After adjusting the steering wheel
Make sure that the steering wheel is securely locked.
The horn may not sound if the steering wheel is not securely locked.
(P. 137)
To sound the horn, press on or
close to the mark.
Page 312 of 860

312 2-4. Using other driving systems
SIENNA_U (OM45477U)
CAUTION
■When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary when any of the following types of vehicles
are in front of you.
As the sensor may not be able to correctly detect these types of vehicles,
the approach warning ( P. 304) will not be activated, and a fatal or serious
accident may result.
● Vehicles that cut in suddenly
● Vehicles traveling at low speeds
● Vehicles that are not moving
● Vehicles with small rear ends (trailers with no load on board etc.)
● Motorcycles traveling in the same lane
■ Conditions under which the vehicle -to-vehicle distance control may
not function correctly
Apply the brakes as necessary in the following conditions as the radar sen-
sor may not be able to correctly detect vehicles ahead, and a fatal or serious
accident may result:
● When water or snow thrown up by the surrounding vehicles hinders the
functioning of the sensor
● When your vehicle is pointing upwards (caused by a heavy load in the lug-
gage compartment, etc.)
● When the road curves or when the lanes are narrow
● When steering wheel operation or your position in the lane is unstable
● When the vehicle ahead of you decelerates suddenly
Page 327 of 860

327
2-4. Using other driving systems
2
When driving
SIENNA_U (OM45477U)
Driving assist systems
To help enhance driving safety and performance, the following sys-
tems operate automatically in res ponse to various driving situations.
Be aware, however, that these systems are supplementary and
should not be relied upon too h eavily when operating the vehicle.
■ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenly, or if
the brakes are applied while driving on a slippery road surface
■Brake assist
Generates an increased level of braking force after the brake pedal is
depressed, when the system detects a panic stop situation
■VSC (Vehicle Stability Control)
Helps the driver to control skidding when swerving suddenly or turning
on slippery road surfaces
■Enhanced VSC (Enhanced Vehicle Stability Control)
Provides cooperative control of the ABS, TRAC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery road
surfaces by controlling steering performance.
■TRAC (Traction Control)
Helps to maintain drive power and prevent the drive wheels from spin-
ning when starting the vehicle or accelerating on slippery roads
■Hill-start assist control (if equipped)
P. 333
■ EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn
the steering wheel
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328 2-4. Using other driving systems
SIENNA_U (OM45477U)
When the Enhanced VSC/TRAC systems are operatingIf the vehicle is in danger of slip-
ping or if any of the drive wheels
spins, the slip indicator light
flashes to indicate that the
Enhanced VSC/TRAC systems
are operating.
A buzzer (intermittent) sounds to
indicate that VSC is operating.
■Active Torque Control 4WD (AWD models only)
Automatically switches from front-wheel drive to AWD (All-Wheel Drive)
according to driving conditions, helping to ensure reliable handling and
stability. Examples of conditions where the system will switch to AWD
are when cornering, going uphill, star ting off or accelerating, and when
the road surface is slippery due to snow or rain etc.
■ VDIM (Vehicle Dynamics In tegrated Management) (if
equipped)
Provides integrated control of the ABS, brake assist, TRAC, VSC, hill-
start assist control, and EPS systems
Helps to maintain vehicle stability when swerving on slippery road sur-
faces by controlling the brakes and engine output
■ PCS (Pre-Collision System) (if equipped)
P. 336
Page 329 of 860
329
2-4. Using other
driving systems
2
When driving
SIENNA_U (OM45477U)
Disabling TRAC and VSC system
If the vehicle gets stuck in fresh snow or mud, TRAC and VSC may
reduce power from the engine to the wheels. You may need to turn
the system off to enable you to rock the vehicle in order to free it.
■ Turning off the TRAC system only
To turn the TRAC system off,
quickly press and release the
button.
The “TRAC OFF” indicator light
will come on.
Push the button again to turn the
system back on.
■Turning off both TRAC and VSC systems
To turn the TRAC and VSC sys-
tems off, press and hold the but-
ton for more than 3 seconds
while the vehicle is stopped.
The “TRAC OFF” indicator light
and VSC OFF indicator light will
come on.
Press the button again to turn the
systems back on.
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330 2-4. Using other driving systems
SIENNA_U (OM45477U)
■When the “TRAC OFF” indicator light comes on even if the VSC OFF
switch has not been pressed
TRAC and hill-start assist control cannot be operated. Contact your Toyota
dealer.
■ Sounds and vibrations caused by ABS, brake assist, Enhanced VSC
and TRAC
● A sound may be heard from the engine compartment when the engine is
started or just after the vehicle begins to move. This sound does not indi-
cate that a malfunction has occurred in any of these systems.
● Any of the following conditions may occur when the above systems are
operating. None of these indicates that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard after the vehicle comes to a stop.
• The brake pedal may pulsate slightly after ABS is activated.
• The brake pedal may move down slightly after ABS is activated.
■ EPS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may
be heard. This does not indicate a malfunction.
■ Reactivation of the TRAC and VSC systems after turning off the engine
Turning off the engine after turning off the TRAC and VSC systems will auto-
matically reactivate them.
■ Reactivation of the TRAC system linked to vehicle speed
When only the TRAC system is turned off, the TRAC system will turn on
when vehicle speed increases. However, when both TRAC and VSC sys-
tems are turned off, the systems will not turn on even when vehicle speed
increases.