2012 TOYOTA SIENNA ECU

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

704 4-3. Do-it-yourself maintenance
SIENNA_U (OM45477U)■
Under the driver’s side instrument panel
FuseAmpereCircuit
1P/OUTLET15 APower outlets
2 RAD NO.2 7.5 A Audio system, navigation system,
rear seat entertainment system
3 ECU-ACC 10 A Main body ECU, clock, shift lock
system, power rear view mirror
control, multiplex communication
system
4 CIG 15 A Power outlets
5 GAUGE NO.1 10 A Emergency flashers, back up
lights, navigation system, multi
information display, automatic tran-
saxle, multiport fuel injection sys-
tem/sequential multiport fuel
injection system, charging system

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)

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)

714 4-3. Do-it-yourself maintenance
SIENNA_U (OM45477U)■
Rear turn signal lights
Remove the securing bolts and
remove the unit.
Turn the bulb base counterclock-
wise.
Remove the light bulb.
STEP1
STEP2
STEP3

718 4-3. Do-it-yourself maintenance
SIENNA_U (OM45477U)
CAUTION
■Replacing light bulbs
● Turn off the lights. Do not attempt to replace the bulb immediately after
turning off the lights.
The bulbs become very hot and may cause burns.
● Do not touch the glass portion of the light bulb with bare hands. Hold the
bulb by the plastic or metal portion.
If the bulb is scratched or dropped it may blow out or crack.
● Fully install light bulbs and any parts used to secure them. Failure to do so
may result in heat damage, fire, or water entering the headlight unit. This
may damage the headlights or cause condensation to build up on the lens.
●Vehicles with discharge headlights:
While the low beam headlights are
turned on, and for a short time after
they have been turned off, metal com-
ponents at the rear of the headlight
assembly will be extremely hot. To pre-
vent burns, do not touch these metal
components until you are certain they
have cooled down.
Metal components

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.

738 5-2. Steps to take in an emergency
SIENNA_U (OM45477U)
■If the malfunction indicator lamp comes on while driving
First check the following:
● Is the fuel tank empty?
If it is, fill the fuel tank immediately.
● Is the fuel tank cap loose?
If it is, tighten it securely.
The malfunction indicator lamp will go off after taking several driving trips.
If the malfunction indicator lamp does not go off even after several trips, con-
tact your Toyota dealer as soon as possible.
■
When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level.
Pushing the tire pressure warning reset switch will not turn off the tire
pressure warning light.
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such
as natural air leaks and tire inflat ion pressure changes caused by tem-
perature. In this case, adjusting the tire inflation pressure will turn off the
warning light (after a few minutes).
■When a tire is replaced with a spare tire (vehicles with compact
spare tire)
The compact spare tire is not equipped with a tire pressure warning
valve and transmitter. If a tire goes flat, the tire pressure warning light will
not turn off even though the flat tire has been replaced with the spare
tire. Replace the spare tire with the re paired tire and adjust the tire infla-
tion pressure. The tire pressure wa rning light will go off after a few min-
utes.