2008 TOYOTA AVALON ECU

348 4-3. Do-it-yourself maintenance
AVALON_U_(L/O_0802)
FuseAmpereCircuit
21 EFI No.1 25 A Multiport fuel injection system/
sequential multiport fuel injection
system, fuel pump
22 HORN 10 A Horn
23 HEAD LH UPR 15 A Left-hand headlight (high beam)
24 HEAD RH UPR 15 A Right-hand headlight (high beam)
25 A/F 25 A Air fuel ratio sensor
26 WASHER 20 A Windshield washer
27 S-HORN 7.5 A Horn
28 DOME 7.5 A Gauges and meters, clock, front
personal lights, door courtesy
lights, garage door opener, rear
personal lights, trunk light
29 ECU-B 10 A Center display, multiplex

communication system
30 RAD No.1 15 A Audio system, center display,

navigation system
31 EFI No.2 10 A Multiport fuel injection system/
sequential multiport fuel injection
system
32 STOP No.2 7.5 A Stop lights, high mounted

stoplight, vehicle stability control
system, anti-lock brake system
33 RADAR CC 7.5 A Vehicle stability control system
34 HEAD RH LWR 15 A Right-hand headlight (low beam)
35 HEAD LH LWR 15 A Left-hand headlight (low beam)

350 4-3. Do-it-yourself maintenance
AVALON_U_(L/O_0802)
FuseAmpereCircuit
11S-HTR20 AAir conditioning system
12DOOR No.225 AMultiplex communication system
13S/ROOF30 AMoon roof
14TA I L10 A
Parking lights, license plate lights,
tail lights, front and rear side
marker lights
15PA N E L7.5 A
Seat heaters, navigation system,
emergency flashers, 
electronically controlled 
automatic transmission system,
glove box light, instrument panel
lights, power outlets
16ECU IG No.110 A
Center display, shift lock control
system, moon roof, multiplex 
communication system, tire pres-
sure monitoring (warning) system
17ECU IG No.210 A
Anti-lock brake system, dynamic
laser cruise control system, 
automatic headlight leveling 
system, vehicle stability control
system, multiplex 
communication system
18HTR7.5 A
Air conditioning system, 
instrument panel lights, electric
cooling fan
19A/C COMP7.5 AAir conditioning system
20GAUGE No.110 ABack-up lights, navigation 
system, emergency flashers
21WIP30 AWindshield wipers
22RR S/SHADE10 ARear sunshade

4
Maintenance and care
351
4-3. Do-it-yourself maintenance
AVALON_U_(L/O_0802)
FuseAmpereCircuit
23IGN10 A
Multiport fuel injection system/
sequential multiport fuel injection
system, SRS airbag system, front
passenger occupant

classification system, smart key
system, starting system, electronic
controlled transmission system
24GAUGE No.27.5 AGauges and meters, center 
display
25ECU-ACC7.5 A
Power rear view mirrors, center
display, shift lock system, 
multiplex communication system
26CIG15 A
27PWR OUTLET15 APower outlets
28RADIO No.27.5 AAudio system, navigation system
29MIR HTR10 AOutside rear view mirror 
defoggers

4
Maintenance and care
359
4-3. Do-it-yourself maintenance
AVALON_U_(L/O_0802)
CAUTION
■
Replacing light bulbs
● Turn off the headlights. Do not attempt to replace the bulb immediately
after turning off the headlights. 
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. Failing 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.
● Do not take apart or repair the low beam discharge headlight bulbs, con-
nectors, power supply circuits, or related components. 
Doing so could result in electric shock and death or serious injury.
■ High-intensity discharge (H ID) headlights (if equipped)
● Contact your Toyota dealer before replacing high-intensity discharge
headlights (including light bulbs).
● Do not touch the high-intensity discharge headlight’s high voltage socket
when the headlights are turned on. An extremely high voltage of 20000V
will be discharged and could result in serious injury or death by electric
shock.
■ To prevent damage or fire
Make sure bulbs are fully seated and locked.

368
5-1. Essential information
AVALON_U_(L/O_0802)
Event data recorder
In a crash or a near car crash eventThe SRS airbag sensor assembly contains the EDR. In a crash or a
near car crash event, this device may record some or all of the follow-
ing information:
● Engine speed
● Whether the brake pedal was applied or not
● Vehicle speed
● To what extent the accelerator pedal was depressed
● Position of the transmission shift lever
● Whether the driver and front passenger wore seat belts or not
● Driver’s seat position
● Front passenger’s occupant classification
● SRS airbag deployment data
● SRS airbag system diagnostic data
If your vehicle is equipped with a vehicle stability control (VSC) sys-
tem, its Electronic C ontrol Unit (ECU) may contain another EDR.
There are a variety of driving sit uations which include activating the
vehicle stability control (VSC) under which the VSC EDR will record
certain information. The VSC EDR may record some or all of the fol-
lowing information:
Your vehicle has computers that monitor and control certain aspects
of your vehicle. These computers assi st in driving and maintaining
optimal vehicle performance.
Besides storing data useful for tr oubleshooting, there is a system to
record data in a crash or a near car crash event. This is called an
Event Data Recorder (EDR).

5
When trouble arises
369
5-1. Essential information
AVALON_U_(L/O_0802)
●
Behavior of the vehicle
● Steering wheel angle
● Vehicle speed
● To what extent the accelerator pedal was depressed
● To what extent the brake pedal was applied
● To what extent the ECU controlled the condition of the 4 wheels
● Vehicle stability contro l system diagnostic data
The information above is intended to be used for the purpose of
improving vehicle safety performan ce. Unlike general data recorders,
the EDR does not record sound data such as conversation between
passengers.
Disclosure of the data
Toyota will not disclose the data re corded in an EDR to a third party
except when:
● An agreement from the vehicle’s ow ner (or the leasing company for
a leased vehicle) is obtained
● Officially requested by the police or other authorities
● Used as a defense for Toyota in a law suit
● Ordered by a court
However, if necessary Toyota will:
● Use the data for research on Toyota vehicle safety performance
● Disclose the data to a third party for research purposes without dis-
closing details of the vehicle ow ner, and only when it is deemed
necessary
● Disclose summarized data cleared of vehicle identification informa-
tion to a non-Toyota organization for research purposes

5
When trouble arises
377
5-2. Steps to take in an emergency
AVALON_U_(L/O_0802)
■
If the malfunction indicator lamp comes on while driving
First check the following:
● Is your vehicle low on gas? 
If it is, refuel the vehicle immediately.
● Is the fuel tank cap loose? 
If it is, tighten it securely.
The light will go off after taking several driving trips. 
If the light does not go off even after several trips, contact your Toyota dealer
as soon as possible.
■ SRS warning light
This warning light system monitors the following:
● The airbag sensor assembly
● Front airbag sensors
● The curtain shield airbag sensors
● The side and curtain shield airbag sensor assemblies
● The driver’s seat position sensor
● Driver’s seat belt buckle switch
● The front passenger occupant classification ECU
● The pressure sensor
● The belt tension sensor
● “AIR BAG ON” and “AIR BA G OFF” indicator lights
● Front passenger’s seat belt buckle switch
● The inflators
● The warning light
● The interconnecting wiring and power sources

384 5-2. Steps to take in an emergency
AVALON_U_(L/O_0802)Loosen the center fastener that
secures the spare tire.
Remove the spare tire cover.
STEP2
STEP3