2012 TOYOTA SIENNA steering

702 4-3. Do-it-yourself maintenance
SIENNA_U (OM45477U)
FuseAmpereCircuit
35 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
36 RAD NO.1 15 A Audio system
37 DOME 7.5 A Vanity lights, personal/interior
lights, personal lights, engine
switch light, rear ceiling lights, door
courtesy lights, luggage compart-
ment light, gauges and meters,
clock
38 ECU-B 10 A Main 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
39 ETCS 10 A Multiport fuel injection system/
sequential multiport fuel injection
system
40 A/F 20 A Multiport fuel injection system/
sequential multiport fuel injection
system
41 STRG LOCK
*620 A Steering lock system
42 ALT-S 7.5 A Charging system

703
4-3. Do-it-yourself maintenance
4
Maintenance and care
SIENNA_U (OM45477U)
*1: Vehicles with discharge headlights only
*2: Vehicles with a 1AR-FE engine only
*3: Vehicles with a 2GR-FE engine only
*4: Vehicles without discharge headlights only
*5: Vehicles without a smart key system only
*6: Vehicles with a smart key system only
FuseAmpereCircuit
43 INJ 25 A Multiport fuel injection system/
sequential multiport fuel injection
system, “IG NO.2” and “IG2” fuses
44 ECU-B NO.2 7.5 A Air conditioning system
45 AM2 NO.2
*67.5 A Multiplex communication system,
starting system
46 EFI NO.1 25 A Multiport fuel injection system/
sequential multiport fuel injection
system, “ECT” and “EFI NO.2”
fuses
47 SMART
*65 A Smart key system
48 DRL 30 A Daytime running light system, “H-
LP LH (HI)” and “H-LP RH (HI)”
fuses
49 EPS 60 A Electric power steering

705
4-3. Do-it-yourself maintenance
4
Maintenance and care
SIENNA_U (OM45477U)
FuseAmpereCircuit
6 ECU-IG NO.1 10 A Multiplex communication system,
stop lights, navigation system,
vehicle stability control system,
Active Torque Control 4WD, intui-
tive parking assist, auto anti-glare
inside rear view mirror, pre-collision
seat belt, outside rear view mirror,
seat heater, TPMS, yaw rate & G
sensor, steering angle sensor,
AUTO ACCESS SEAT, main body
ECU
7 P/W RL 20 A Rear power windows (left-side)
8 D/L 15 A Power door lock system
9 P/SEAT FR 30 A Power front seat (right-side)
10 S/ROOF 30 A Moon roof 11 P/W RR 20 A Rear power windows (right-side)
12 P/W FR 20 A Front power windows (right-side)
13 P/SEAT FL 30 A Power front seat (left-side), driving
position memory system
14 STOP 10 A Stop lights, ABS, vehicle stability
control system, rear combination
light, high mounted stop light, auto-
matic transaxle, shift lock system,
multiplex communication system,
power third seat switch, multiport
fuel injection system/sequential
multiport fuel injection system,
trailer lights (stop lights)
15 P/W FL 20 A Front power windows (left-side)

706 4-3. Do-it-yourself maintenance
SIENNA_U (OM45477U)
FuseAmpereCircuit
16 PSD LH 25 A Power sliding door (left-side)
17 4WD 7.5 A Active Torque Control 4WD
18 AM1 10 A Starting system
19 GAUGE NO.2 7.5 A Gauges and meters, multi informa-
tion display
20 IG2 7.5 A Automatic transaxle, multiport fuel
injection system/sequential multi-
port fuel injection system, SRS air-
bag system, front passenger
occupant classification system,
steering lock system, smart key
system, starting system, fuel pump
21 PANEL 10 A Air conditioning system, navigation
system, front passenger’s seat belt
reminder light, audio system, steer-
ing switch, intuitive parking assist
switch, personal/interior light main
switch, shift lever light, headlight
levering switch, power door lock
main switch, clock, power quarter
window switch, seat heater switch,
emergency flashers, rear window
defogger switch, vehicle stability
control off switch, console box light,
power slide switch light

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)

5
When trouble arises
731
5-2. Steps to take in an emergency
SIENNA_U (OM45477U)
Warning lightWarning light/Details
(U.S.A.)
(Canada) “ABS” warning light
Indicates a malfunction in:
• The ABS; or
• The brake assist system
Electric power steering system warning light
Indicates a malfunction in the EPS (Electric Power Steer-
ing) system
(comes on or flashes) Pre-collision system warni
ng light (if equipped)
Indicates a malfunction in the pre-collision system
The warning light will operate as follows, even when the
system is not malfunctioning:
• The light will flash quickly when the system is operating. (P. 336)
• The light will turn on when the pre-collision braking is dis- abled. ( P. 337)
• The light will turn on when the system cannot temporarily be used.
Slip indicator light Indicates a malfunction in:
• Enhanced VSC
•TRAC
The indicator will blink when the system listed above is
operational. ( P. 328)

5
When trouble arises
737
5-2. Steps to take in an emergency
SIENNA_U (OM45477U)
■
SRS warning light
This warning light system monitors the airbag sensor assembly, front airbag
sensors, side and curtain shield airbag sensors, curtain shield airbag sen-
sors, driver’s seat position sensor, driver’s seat belt buckle switch, front pas-
senger occupant classification system (ECU and sensors), “AIR BAG ON”
indicator light, “AIR BAG OFF” indicator light, front passenger’s seat belt
buckle switch, seat belt pretensioner assemblies, inflators, interconnecting
wiring and power sources. ( P. 168)
■ Front passenger detection sensor and passenger seat belt reminder
● If luggage is placed on the front passenger seat, the front passenger
detection sensor may cause the warning light to flash even if a passen-
ger is not sitting in the seat.
● If a cushion is placed on the seat, the sensor may not detect a passen-
ger, and the warning light may not operate properly.
■ Electric power steering system warning light
When the voltage is low drops, the electric power steering system warning
light may come on.

5
When trouble arises
741
5-2. Steps to take in an emergency
SIENNA_U (OM45477U)
CAUTION
■When the electric power steering system warning light comes on
The steering wheel may become extremely heavy.
If the steering wheel becomes heavier than usual when operating, hold
firmly and operate using more force than usual.
■If the tire pressure warning light comes on
Be sure to observe the following precautions. Failure to do so could
cause loss of vehicle control and result in death or serious injury.
●Vehicles with standard tires:
• Stop your vehicle in a safe place as soon as possible. Adjust the
tire inflation pressure immediately.
• If the tire pressure warning light comes on even after tire inflation pressure adjustment, it is probable that you have a flat tire. Check
the tires. If a tire is flat, change it with the spare tire and have the
flat tire repaired by the nearest Toyota dealer.
• Avoid abrupt maneuvering and brak ing. If the vehicle tires deterio-
rate, you could lose control of th e steering wheel or the brakes.
●Vehicles with run-flat tires:
• Decelerate to the lowest appropr iate speed as soon as possible.
Do not drive over 55 mph (90 km/h).
• Check and adjust the tire inflation pressure immediately.
• If the tire pressure warning light comes on even after tire inflation pressure adjustment, it is probable that you have a flat tire. Have
the tire replaced by the nearest Toyota dealer.
• Avoid abrupt maneuvering and brak ing. If the vehicle tires deterio-
rate, you could lose control of th e steering wheel or the brakes.