Page 25 of 5135
01±26±
INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
AVENSIS REPAIR MANUAL (RM1018E)
Symptoms exist
No symptoms exist
a Go to step 5
b
4 Simulation test using the symptom simulation methods
5 DTC check
DTC displayed
Normal code displayed
a Troubleshooting of problem indicated by DTC
b
6 Symptom confirmation
No symptoms exist
Symptoms exist
If a DTC is displayed in the initial DTC check, it indicates that
a trouble may have occurred in a wire harness or connector in
that circuit in the past. Therefore, check the wire harness and
connectors (See page 01±32). a System normal
b
Troubleshooting of each problem symptom
The problem is still occurring in a place other than the diagnostic circ\
uit (The DTC displayed first is either
for a past problem or a secondary problem).
Page 26 of 5135

D25083
Vibrate Slightly
Shake Slightly
Vibrate
Slightly
D25084
Malfunction
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS01±27
AVENSIS REPAIR MANUAL (RM1018E)
SYMPTOM SIMULATION
HINT:
The most difficult case in troubleshooting is when no symptoms occurs. In such cases, a thorough customer
problem analysis must be carried out. Then the same or similar conditions and environment in which the
problem occurred in the customer's vehicle should be simulated. No matter how much experience a techni-
cian has, or how skilled he may be, if he proceeds to troubleshoot without confirming the problem symptoms,
he will tend to overlook something important in the repair operation and make a wrong guess somewhere,
which will only lead to a standstill. For example, for a problem which only occurs when the engine is cold,
or for a problem which occurs due to vibration caused by the road during driving, etc., the problem can never
be determined when the engine is hot or when the vehicles is at a standstill. Since vibration, heat or water
penetration (moisture) is a likely cause for the problem which is difficult to reproduce, the symptom simulation
tests introduced here are effective measures in a point that the external causes are applied to the vehicle
in a stationary condition.
Important points in the symptom simulation test:
In the symptom simulation test, the problem symptoms should be confirmed, and the problem area or parts
must also be discovered. To do so, reduce the possible problem circuits according to the symptoms before
starting this type of test and have the hand±held tester connected beforehand. After that, carry out the symp-
tom simulation test, judging whether the circuit being tested is defective or normal and also confirming the
problem symptoms at the same time. Refer to the problem symptoms table of each system to narrow down
the possible causes of the symptom.
1. VIBRATION METHOD: When vibration seems to be
the major cause.
(a) PART AND SENSOR
(1) Apply slight vibration with your finger to the part of
the sensor considered to be the problem cause and
check whether the malfunction occurs.
HINT:
Applying strong vibration to relays may result in open relays.
(b) CONNECTORS
(1) Slightly shake the connector vertically and horizon-
tally.
(c) WIRE HARNESS
(1) Slightly shake the wire harness vertically and hori-
zontally.
The connector joint and fulcrum of the vibration are
the major areas that should be checked thoroughly.
2. HEAT METHOD: If the problem seems to occur when
the area in question is heated.
(a) Heat the component that is the possible cause of the mal-
function with a hair dryer or similar object. Check if the
malfunction occurs.
NOTICE:
Do not heat the components to more than 60C
(140F) (Temperature is limited to keep the compo-
nents from being damaged).
Page 27 of 5135

D25085
B02389
ON 01±28
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
AVENSIS REPAIR MANUAL (RM1018E)
Do not apply heat directly to the parts in the ECU.
3. WATER SPRINKLING METHOD: When the malfunc-
tion seems to occur on a rainy day or in high±humid-
ity.
(a) Sprinkle water onto the vehicle and check if the malfunc-
tion occurs.
NOTICE:
Never sprinkle water directly onto the engine
compartment, but indirectly change the temperature
and humidity by spraying a mist of water onto the ra-
diator front surface.
Never apply water directly onto the electronic compo-
nents.
HINT:
If a vehicle is subject to water leakage, the leaking water may
contaminate the ECU. When testing a vehicle with a water leak-
age problem, this factor must also be considered.
4. OTHERS: If the malfunction seems to occur when
electrical load is excessive.
(a) Turn on all the electrical equipment including the heater
blower, headlights, rear window defogger, etc., and check
if the malfunction occurs.
Page 28 of 5135

Detection Item
Indicates the system or details of the
problem. Trouble Area
Indicates the suspect areas of
the problem.
Detection Item
DTC No.
(See page)
Trouble Area
SRS
Steering wheel pad (squib)
Spiral cable
Airbag sensor assembly
Wire harness
B0103/12
(05±132) B0102/11
(05±128)
DIAGNOSTIC TROUBLE CODE CHART
If a malfunction code is displayed during the DTC check, check the circuit for that code liste\
d in the table
below (Proceed to the page given for that circuit).
Short in D squib circuit
Open in D squib circuit
B0101/14
(05±124)
Short in D squib circuit (to ground)
Short in D squib circuit (to B+)
Warning Light
ON
ON
ON
ON
Steering wheel pad (squib)
Spiral cable
Airbag sensor assembly
Wire harness
Steering wheel pad (squib)
Spiral cable
Airbag sensor assembly
Wire harness
Steering wheel pad (squib)
Spiral cable
Airbag sensor assembly
Wire harness
B0105/53
(05±136) ON
Airbag sensor assembly
Wire harness
B0106/54
Open in P squib circuit
Airbag sensor assembly
Wire harness
Short in P squib circuit (to Ground) ON
ON
B0100/13
(05±119)
Short in P squib circuit
Front passenger airbag assembly (squib)
Airbag sensor assembly
Wire harness
Front passenger airbag assembly (squib)
Front passenger airbag assembly (squib)
Page or Instructions
Indicates the page where the inspection proce-
dures for each circuit is to be found, or gives
instructions for checking and repairs.
DTC No.
Indicates the diagnostic trouble code.
±
INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS01±29
AVENSIS REPAIR MANUAL (RM1018E)
DIAGNOSTIC TROUBLE CODE CHART
The inspection procedures are shown in the table below. This table allows efficient and accurate trouble-
shooting using the diagnostic trouble codes displayed in the diagnostic trouble code chart. Proceed with
troubleshooting in accordance with the inspection procedures listed in the diagnostic c\
hart corresponding
to the diagnostic trouble codes displayed. The diagnostic trouble code chart for the Supplemental Restraint
System is shown below as an example.
Page 29 of 5135

01±30±
INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
AVENSIS REPAIR MANUAL (RM1018E)
PROBLEM SYMPTOMS TABLE
The suspected circuits or parts for each problem symptom are shown in the t\
able below. Use this table to
troubleshoot the problem when a Normal code is displayed in the diagnostic trouble c\
ode chart but the prob-
lem is still occurring. Numbers in the table indicate the order in which\
the circuits or parts should be checked.
HINT:
When the problem is not detected by the diagnostic system even though the pr\
oblem symptom is present,
it may be that the problem is occurring outside the detection range of t\
he diagnostic system.
Symptom Suspected AreaSee page
1. With the ignition switch in ACC or ON position, the SRS warning
light sometimes lights up after approx. 6 seconds have elapsed.
2. SRS warning light is always lit up even when ignition switch is
in the LOCK position
1. With the ignition switch in the ACC or ON position, the SRS
warning light does not light up.
PROBLEM SYMPTOMS TABLE
1. DTC is not displayed. 05±187 05±183
Problem SymptomPage
Indicates the page where the flow chart for each circuit
is located.
Circuit Inspection, Inspection Order
Indicates the circuit which needs to be checked for each problem
symptom. Check in the order indicated by the numbers.
Circuit or Part Name
Indicates the circuit or part which needs to be checked.
Proceed with troubleshooting of each circuit in the table below.
1. SRS warning light circuit
(Always lights up when ignition switch is in
LOCK position.)
1. SRS warning light circuit
(Does not light up when ignition switch is turned
to ACC or ON.)
1. Tc terminal circuit
05±180
3. DTC is displayed without Tc and CG terminal connection. 2. SRS warning light is always lit up at the time of DTC check
procedure.
Page 30 of 5135

SFI
SFISFI
SFISFI
SFI
D25842
Circuit Description
The major role and, operation of the circuit
and its component parts are explained.
Diagnostic Trouble Code No. and Detection Item
Indicates the diagnostic trouble codes, diagnostic
trouble code settings and suspect areas for a
problem.
Wiring Diagram
This shows a wiring diagram of the circuit.
Use this diagram together with ELECTRICAL
WIRING DIAGRAM to thoroughly understand the
circuit.
Wire colors are indicated by an alphabetical code.
B = Black, L = Blue, R = Red, BR = Brown,
LG = Light Green, V = Violet, G = Green,
O = Orange, W = White, GR = Gray, P = Pink,
Y = Yellow, SB = Sky Blue
The first letter indicates the basic wire color and
the second letter indicates the color of the stripe.Inspection Procedures
Use the inspection procedures to determine
if the circuit is normal or abnormal. If it is ab-
normal, use it to determine whether the prob-
lem is located in the sensors, actuators, wire
harness or ECU.
Indicates the condition of the connector of the ECU
during the check.
Connections of tester are
indicated by (+), (±) after
terminals name.
Connector being checked
is connected.Connector being checked
is disconnected.
For inspection of connector
with body ground, there is
nothing about the body
ground written down.
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS01±31
AVENSIS REPAIR MANUAL (RM1018E)
CIRCUIT INSPECTION
How to read and use each page is shown below.
Page 31 of 5135

010B6±13
±
INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS01±21
AVENSIS REPAIR MANUAL (RM1018E)
HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
GENERAL INFORMATION
There are many ECU controlled systems used in the AVENSIS. In general, ECU controlled system are con-
sidered to be very intricate and require a high level of technical knowledge an\
d expert skill to troubleshoot.
The fact is, however, that if you proceed by inspecting the circuits one by one, troubleshoo\
ting of these sys-
tems is not complex. If you have adequate understanding of the system and ba\
sic knowledge of electricity,
the problem can be accurately diagnosed and fixed. This manual is design\
ed based on the above principle
to help service technicians perform accurate and effective troubleshooting, and is compiled for the following
major ECU controlled systems:
The troubleshooting procedures are described on the following pages.
SystemPage
1. SFI System [1ZZ±FE, 3ZZ±FE]05±1
2. SFI System [1AZ±FE]05±143
3. SFI System [1AZ±FSE]05±290
4. ECD System [1CD±FTV]05±523
5. ABS with EBD System05±696
6. ABS with EBD & BA & TRC & VSC System05±752
7. Electronic Controlled Automatic Transmission [ECT] [U241 (1AZ±FE)]05±856
8. Electronic Controlled Automatic Transmission [ECT] [U241 (1AZ±FSE)]05±915
9. Electronic Controlled Automatic Transmission [ECT] [U341]05±980
10.Electronic Motor Power Steering System05±1042
11. Air Conditioning System05±1088
12.Combustion Type Power Heater System05±1161
13.Supplemental Restraint System05±1181
14.Audio System05±1393
15.Navigation System05±1435
16.Combination Meter05±1497
17.Power Door Lock Control System05±1534
18.Wireless Door Lock Control System05±1568
19.Key Reminder Warning System05±1586
20.Engine Immobiliser System05±1599
21.Theft Deterrent System05±1627
22.Multiplex Communication System05±1654
23.Cruise Control System05±1697
FOR USING HAND±HELD TESTER
Before using the tester, the tester's operator manual should be read thoroughly.
If the tester cannot communicate with the ECU controlled systems when you \
have connected the cable
of tester to the DLC3, turned the ignition switch ON and operated the test\
er, there is a problem on the
vehicle side or tester side.
(1) If the communication is normal when the tester is connected to another veh\
icle, inspect the diag-
nosis data link line (Bus line) or ECU power circuit of the vehicle.
(2) If the communication is still impossible when the tester is connected to a\
nother vehicle, the prob- lem is probably in the tester itself, so perform the Self Test procedures outlined in the Tester Oper-
ator 's Manual.
Page 32 of 5135

010B5±11
D25082
Rubber Attachment
D27697
: SUPPORT POSITION, PAN
TOGRAPH JACK POSITION
: CENTER OF VEHICLE GRAVITY
(unload condition)
: JACK POSITION
± INTRODUCTIONREPAIR INSTRUCTION
01±19
AVENSIS REPAIR MANUAL (RM1018E)
VEHICLE LIFT AND SUPPORT LOCATIONS
1. NOTICE ABOUT VEHICLE CONDITION WHEN JACKING UP
(a) As a rule, the vehicle must be unloaded when jacking up. Never jack up or lift up the vehicle loaded
with things of heavy weight.
(b) When removing any parts of heavy weight like the engine and transmission, the center of gravity of
the vehicle moves. Place a balance weight so as to keep it from rolling, or hold the jacking support
location using the mission jack.
2. NOTICE FOR USING 4 POST LIFT
(a) Follow the instruction manual for a safety operation.
(b) Do not damage tires or wheels with a free wheel beam.
(c) Using a wheel stopper, fix the vehicle.
3. NOTICE FOR USING JACK AND SAFETY STAND
(a) Work in the flat place using a wheel stopper at all times.
(b) Use a safety stand with a rubber attachment, as shown
in the illustration.
(c) Support the specified location with a jack and safety stand
accurately.
(d) When jacking up the front wheels, release the parking
brake and place wheel stoppers only behind the rear
wheels. When jacking up the rear wheels, place wheel
stoppers only in front of the front wheels.
(e) Do not work or leave the vehicle supported only by a jack.
Be sure to support the vehicle with a safety stand.
(f) When jacking up only the front wheels or only the rear wheels, place wheel stoppers to both sides of
the wheels that contact ground.
(g) When jacking down the vehicle with its front wheels jacked up, release the parking brake and place
wheel stoppers only in front of the rear wheels. When jacking down the vehicle with its rear wheels
jacked up, place wheel stoppers only behind the front wheels.