Page 711 of 872
711
4-3. Do-it-yourself maintenance
4
Maintenance and care
SIENNA_OM_OM45483U_(U)
Checking and replacing fuses
If any of the electrical components do not operate, a fuse may have
blown. If this happens, check and replace the fuses as necessary.
Vehicles without a smart key system
Turn the engine switch off.
Vehicles with a smart key system
Turn the “ENGINE START STOP” switch OFF.
Open the fuse box cover.
Engine compartment Push the tab in and lift the lid
off.
Driver’s side instrument panel Remove the lid.STEP1
STEP2
Page 714 of 872
714 4-3. Do-it-yourself maintenance
SIENNA_OM_OM45483U_(U)
Fuse layout and amperage ratings■ Engine compartment
FuseAmpereCircuit
1H-LP LVL
*17.5 A Headlight leveling system
2 DSS1 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 717 of 872

717
4-3. Do-it-yourself maintenance
4
Maintenance and care
SIENNA_OM_OM45483U_(U)
FuseAmpereCircuit
32 ALT 140 A Charging system, horn, left-hand
headlight (low beam), right-hand
headlight (low beam), fog light, out-
side rear view mirror heaters, rear
window defoggers, windshield
wiper de-icer
33 RAD NO.1 15 A Audio system
34 DOME 7.5 AVanity lights, personal/interior
lights, personal lights, engine
switch light, rear ceiling lights, door
courtesy lights, luggage compart-
ment light, gauges and meters,
clock
35 ECU-B 10 AMain body ECU, smart key system,
wireless remote control, power
back door, power sliding door, rear
view monitor, multi information dis-
play, power window, outside rear
view mirror control, steering angle
sensor, auto-anti glare inside rear
view mirror, AUTO ACCESS SEAT
remote control, front passenger
occupant classification system
36 ETCS 10 AMultiport fuel injection system/
sequential multiport fuel injection
system
37 A/F 20 AMultiport fuel injection system/
sequential multiport fuel injection
system
38 STRG LOCK
*420 A Steering lock system
39 ALT-S 7.5 A Charging system
Page 727 of 872
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4-3. Do-it-yourself maintenance
4
Maintenance and care
SIENNA_OM_OM45483U_(U)
■
Front fog lights (if equipped)
Remove the engine under cover
bolt and pull down the engine
under cover.
Unplug the connector while
pushing the lock release.
Turn the bulb base counterclock-
wise.
STEP1
STEP2
STEP3
Page 735 of 872

When trouble arises5
735
SIENNA_OM_OM45483U_(U)
5-1. Essential informationEmergency flashers ......... 736
If your vehicle needs to be towed .................... 737
If you think something is wrong ......................... 741
Fuel pump shut off system ........................... 742 5-2. Steps to take in an
emergency
If a warning light turns on or a warning buzzer
sounds... ....................... 743
If a warning message is displayed........................ 758
If you have a flat tire (vehicles with
run-flat tires)................... 759
If you have a flat tire (vehicles with
standard tires) ................ 761
If the engine will not start .......................... 776
If the shift lever cannot be shifted from P............ 778
If you lose your keys ........ 780
If the electronic key does not operate properly....... 781
If the battery is discharged ..................... 784
If your vehicle overheats ....................... 790
If the vehicle becomes stuck .............................. 793
If your vehicle has to be stopped in an
emergency ..................... 795
Page 736 of 872
736
SIENNA_OM_OM45483U_(U)
5-1. Essential information
Emergency flashers
NOTICE
■To prevent battery discharge
Do not leave the emergency flashers on longer than necessary when the
engine is not running.
Use the emergency flashers if th e vehicle malfunctions or is
involved in an accident.
Press the switch to flash all
the turn signal lights. To turn
them off, press the switch
once again.
Page 737 of 872
5
When trouble arises
737
5-1. Essential information
SIENNA_OM_OM45483U_(U)
If your vehicle needs to be towed
Before towingThe following may indicate a problem with your transaxle. Contact
your Toyota dealer before towing.
● The engine is running but the vehicle will not move.
● The vehicle makes an abnormal sound.
If towing is necessary, we recommend having your vehicle towed by
your Toyota dealer or a commercial towing service, using a wheel-lift
type truck or flat bed truck.
Use a safety chain system for all to wing, and abide by all state/pro-
vincial and local laws.
2WD models: If towing your vehicle with a wheel-lift type truck from
the front, the vehicle’s rear wheels and axles must be in good condi-
tions. ( P. 738, 740)
If they are damaged, use a towing dolly or flat bed truck.
AWD models: If towing your vehicle with a wheel-lift type truck, use a
towing dolly. ( P. 738, 740)
Page 741 of 872
5
When trouble arises
741
5-1. Essential information
SIENNA_OM_OM45483U_(U)
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