TOYOTA AVENSIS 2002 Repair Manual

IN0383
Example
Ground
IN0384
Ground ECU Side
W/H Side
Ground
01±36± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
AVENSIS REPAIR MANUAL (RM1018E)
4. CHECK AND REPLACE ECU
NOTICE:

Start an inspection of the connector from the back-
side of the connector on the wire harness side with
the connector connected to the ECU.

When no measurement condition is specified, per-
form the inspection with the engine stopped and also
the ignition switch ON.
(a) First check the ECU ground circuit. If it is faulty, repair it.
If it is normal, the ECU could be faulty. In this case, re-
place the ECU with one that functions normally and check
if the symptoms appear.
(1) Measure the resistance between the ECU ground
terminal and body ground.
Resistance: 1
or less
(2) Disconnect the ECU connector, check the ground
terminals on the ECU side and wire harness side for
bends and check the contact pressure.

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.

010B7±13
01±22± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
AVENSIS REPAIR MANUAL (RM1018E)
HOW TO PROCEED WITH TROUBLESHOOTING
HINT:
Carry out troubleshooting in accordance with the procedures on the following page. Here, only the basic
procedures are shown. Details are provided in the Diagnostics Section, showing the most effective methods
for each circuit. Confirm the troubleshooting procedures first for the relevant circuit before beginning trouble-
shooting of that circuit.
1 Vehicle brought to workshop
2 Customer problem analysis
(a) Ask the customer about the conditions and environment when the problem occurred.
3 Symptom confirmation and DTC (and freeze frame data) check
(a) Check the battery positive voltage.
Voltage: 11 ± 14 V (Engine stopped)
(b) Visually check the wire harness, connectors and fuses for open and short, etc.
(c) Warm up the engine to the normal operating temperature.
(d) Confirm the problem symptoms and conditions, and check for DTCs according to the related chart.
OK Go to step 5
NG
4 DTC chart
(a) Check the results obtained in step 3, then confirm the inspection procedures for the system or the part
which should be checked using the DTC chart.
Go to step 6
5 Problem symptoms chart
(a) Check the results obtained in step 3, then confirm the inspection procedures for the system or the part
which should be checked using the problem symptoms table.
6 Circuit inspection or parts inspection
(a) Confirm the circuit for the system or the part which should be checked using the problem symptoms
table or the results obtained in step 4.
7 Repair
(a) Repair the affected system or part in accordance with the instructions in step 6.

± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS01±23
AVENSIS REPAIR MANUAL (RM1018E)
8 Confirmation test
(a) After completing repairs, confirm that the problem has been solved (If the problem does not recur, per-
form a confirmation test under the same conditions and in the same environment as when it occurred
for the first time).
END

Important Points with Customer Problem Analysis

What ±±±±± Vehicle model, system name

When ±±±±± Date, time, occurrence frequency

Where ±±±±± Road conditions

Under what conditions? ±±±±± Running conditions, driving conditions, weather conditions

How did it happen? ±±±±± Problem symptoms
(Sample) Supplemental restraint system check sheet.
Supplemental Restraint System Check Sheet
Customer's Name
Date Vehicle Brought In
Registration No.
Frame No.
Odometer Reading
km
miles
Date Problem First Occurred
Weather
Temperature
Vehicle OperationFine Cloudy
StartingIdling
Driving
Constant speed Acceleration
OtherInspector's
Name
CUSTOMER PROBLEM ANALYSIS CHECK
Registration Year
RainySnowyOther / / / /
/ /
Approx.
Deceleration [
]
01±24± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
AVENSIS REPAIR MANUAL (RM1018E)
CUSTOMER PROBLEM ANALYSIS
HINT:
In troubleshooting, the problem symptoms must be confirmed accurately, meaning that all preconcep-
tions must be set aside in order to make an accurate judgement. To ascertain what the problem symp-
toms are, it is extremely important to ask the customer about the problem and conditions when it oc-
curred.
The following 5 items are important points in the problem analysis. Past problems which are thought
to be unrelated and the repair history, etc. may also help in some cases. Therefore, as much informa-
tion as possible should be gathered and its relationship with the problem symptoms should be correctly
ascertained for use as reference in troubleshooting. A customer problem analysis table is provided for
your use in the Diagnostics Section for each system.

± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS01±25
AVENSIS REPAIR MANUAL (RM1018E)
SYMPTOM CONFIRMATION AND DIAGNOSTIC TROUBLE CODE
HINT:

The diagnostic system in AVENSIS has various functions. The first function is the Diagnostic Trouble
Code (DTC) Check, in which a malfunction in the signal circuits to the ECU is stored in code form in
the ECU memory. Another function is the Input Signal Check, which checks if the signals from various
switches are sent to the ECU correctly. By using these check functions, it is possible to quickly narrow
down potential problem areas and troubleshooting can be performed effectively. The diagnostic func-
tions are incorporated in the following systems in the AVENSIS.
SystemDiagnostic Trouble
Code CheckInput Signal Check
(Sensor Check)Diagnostic Test
Mode (Active Test)
SFI System (1AZ±FE/1AZ±FSE, 1ZZ±FE/3ZZ±FE)

(with Check Mode)


ECD System (1CD±FTV)

(with Check Mode)


ABS with EBD System



ABS with EBD & BA & TRC & VSC System



Electronically Controlled Automatic Transmission [ECT]

(with Check Mode)

Air Conditioning System


Supplemental Restraint System

Audio System

Power Door Lock Control System


Wireless Door Lock Control System

Key Reminder Warning System

Engine Immobiliser System


Theft Deterrent System


Multiplex Communication System

Cruise Control System



In the DTC check, it is very important to determine whether the problem indicated by the DTC is still
occurring or has occurred in the past but returned to normal at present. In addition during the problem
symptom check, it a check must be made on whether the malfunction indicated by the DTC is directly
related to the problem symptom or not. For this reason, the DTC should be checked before and after
symptom confirmation to determine the current conditions. If this is not done, it may, depending on the
case, result in unnecessary troubleshooting for systems that are operating normally. This would make
more difficult to detect the problem area or to try to repair irrelevant areas. Therefore, always follow
the procedures in the correct order and perform the DTC check.

A flow chart showing how to proceed with troubleshooting using the diagnostic trouble code (DTC)
check is shown the this page. This flow chart shows how to utilize the DTC check effectively. Then,
by carefully checking the results, this chart indicates how to proceed either to the DTC troubleshooting
or to the troubleshooting of the problem symptoms table.
1 DTC check
2 Make a note of DTCs displayed and then clear the memory
3 Symptom confirmation

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).

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).

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.

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.