2002 TOYOTA AVENSIS Repair Manual

010B8±08
D25086
WRONG
CORRECT
D25087
Looseness of Crimping
Core Wire
Terminal
Deformation
Pull Lightly 01±32
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
AVENSIS REPAIR MANUAL (RM1018E)
ELECTRONIC CIRCUIT INSPECTION PROCEDURE
1. BASIC INSPECTION
(a) RESISTANCE MEASURING CONDITION OF ELECTRONIC PARTS
(1) Unless stated, all resistance is measured at an ambient temperature of 20C (68F). As the re-
sistance may be outside the specifications if measured at high temperatures immediately after
the vehicle has been running, measurements should be made when the engine has cooled
down.
(b) HANDLING OF CONNECTOR
(1) When removing the connector with lock, press the
connector in the direction of the engagement and
remove the lock by lightly pressing the lock claw.
(2) When removing the connector, do not hold the har-
ness, but hold the connector.
(3) Before connecting the connector, check that there
is no deformation, damage or missing terminals.
(4) The connector with a lock should be securely con-
nected until it makes a ºclickº sound.
(5) When checking the connector with a Toyota electri-
cal tester, check it from the backside (harness side)
of the connector using a mini test lead.
NOTICE:

As a water proof connector cannot be checked from
the backside, check by connecting the sub±harness.

Do not damage the terminals by moving the inserted
tester needle.
(c) CONNECTOR CHECKING POINTS
(1) Checking when the connector is connected:
By holding the connector, check the inserted condi-
tion and locking efficiency (engaged condition).
(2) Checking when the connector is removed:
Check by lightly pulling the wire harness (missing
terminal, terminal crimping condition, core wire
break).
Check visually for any rust, metal particles, water
and bent terminals (rust, mixing of foreign object,
terminal deformation).
NOTICE:
When testing a gold±plated female terminal, always use a
gold±plated male terminal.

D25088
Same terminal as
a male terminal
D20024
WRONG
CORRECT
D01557
WRONG
Z17004
C
SensorOPEN
1
2B
1
21
21
2A
Fig. 1
ECU
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS01±33
AVENSIS REPAIR MANUAL (RM1018E)
(3) Checking of the contact pressure of the terminal:
Prepare a spare male terminal.
Insert it into a female terminal, check the engaged
condition and sliding resistance.
(d) REPAIR METHOD OF CONNECTOR TERMINAL
(1) If there is on the contact point, clean the contact
point using an air gun or shop rag. However, never
polish the contact point using sand paper as the
platings may come off.
(2) In case of abnormal contact pressure, replace the
female terminal. However, if a male terminal is gold±
plated (gold color), use gold±plated female terminal
and if it is silver±plated (silver color), use silver±
plated female terminal.
(e) HANDLING OF WIRE HARNESS
(1) When removing the wire harness, check the posi-
tioning of the wiring and clamping before starting
work in order to be able to restore it correctly.
(2) Never twist, pull or loosen the wire harness more
than necessary.
(3) Never allow the wire harness to come into contact
with a high±temperature, rotating, moving, vibrating
or sharp (edge of the panel, tip of the screw, etc.)
part.
(4) When installing parts, never let the wire harness be
interfered with.
(5) Never cut or break the cover of the wire harness. If
one is cut or broken, replace it or securely repair it
with electrical tape.
2. CHECK OPEN CIRCUIT
(a) For the open circuit in the wire harness in Fig. 1, perform
a continuity check in step (b) or a voltage check in step (c)
to locate the section.

Z17005
Fig. 2
Sensor
C
BA
ECU
1
21
22 1
B04722
Fig. 3
Sensor
B2
A
1
21
2
21
C
B1
1
2ECU
Z17007
Fig. 4
Sensor
CBA
1
21
2
2 15V
5V
0V 01±34
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
AVENSIS REPAIR MANUAL (RM1018E)
(b) Check the continuity.
(1) Disconnect connectors A and C and measure the
resistance between them.
Resistance: 1
or less
HINT:
Measure the resistance while lightly shaking the wire harness
vertically and horizontally.
In the case of Fig. 2:
Between terminal 1 of connector A and terminal 1
of connector C
No continuity (open)
Between terminal 2 of connector A and terminal 2
of connector C
Continuity
Therefore, the cause is an open circuit between ter-
minal 1 of connector A and terminal 1 of connector
C.
(2) Disconnect connector B and measure the resis-
tance between the connectors.
In the case of Fig. 3:
Between terminal 1 of connector A and terminal 1
of connector B1
Continuity
Between terminal 1 of connector B2 and terminal 1
of connector C
No continuity (open)
Therefore, the cause is an open circuit between ter-
minal 1 of connector B2 and terminal 1 of connector
C.
(c) Check the voltage.
(1) In a circuit in which voltage is applied (to the ECU
connector terminal), an open circuit can be checked
by conducting a voltage check.
As shown in Fig. 4, with each connector still con-
nected, measure the voltage between the body
ground and terminal 1 of connector A at the ECU 5
V output terminal, terminal 1 of connector B, and
terminal 1 of connector C, in that order.
(2) If the results are:
5 V: Between terminal 1 of connector A and body
ground
5 V: Between terminal 1 of connector B and body
ground
0 V: Between terminal 1 of connector C and body
ground
Therefore, the cause is an open circuit in the wire
harness between terminal 1 of connector B and ter-
minal 1 of connector C.

Z17008
CSHORT
1
2B
1
21
2 A
Fig. 5
Z17009
Fig. 6
Sensor
C
BA
ECU
1
21
22 1
Z17808
Fig. 7
Sensor
B2
A
11 1
C
B1
1ECU
2
222
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS01±35
AVENSIS REPAIR MANUAL (RM1018E)
3. CHECK SHORT CIRCUIT
(a) If the wire harness is ground shorted as shown in Fig. 5,
locate the section by conducting a continuity check with
the body ground in step (b).
(b) Check the continuity with the body ground.
(1) Disconnect connectors A and C and measure the
resistance between terminals 1 and 2 of connector
A and the body ground.
Resistance: 10 k
or higher
HINT:
Measure the resistance while lightly shaking the wire harness
vertically and horizontally.
In the case of Fig. 6:
Between terminal 1 of connector A and body
ground Continuity (short)
Between terminal 2 of connector A and body
ground No continuity
Therefore, the cause is a short circuit between ter-
minal 1 of connector A and terminal 1 of connector
C.
(2) Disconnect connector B and measure the resis-
tance between terminal 1 of connector A and the
body ground, and terminal 1 of connector B2 and
the body ground.
In the case of Fig. 7:
Between terminal 1 of connector A and body
ground No continuity
Between terminal 1 of connector B2 and body
ground Continuity (short)
Therefore, the cause is a short circuit between ter-
minal 1 of connector B2 and terminal 1 of connector
C.

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