INTRODUCTION

HOW TO USE THIS MANUAL . . . . . . . . . . . . . IN–1

GENERAL INFORMATION . . . . . . . . . . . . . . . . . . IN–1
IDENTIFICATION INFORMATION . . . . . . . . . . IN–3
ENGINE SERIAL NUMBER . . . . . . . . . . . . . . . . . IN–3
REPAIR INSTRUCTIONS . . . . . . . . . . . . . . . . . IN–4
GENERAL INFORMATION . . . . . . . . . . . . . . . . . . IN–4
FOR ALL OF VEHICLES . . . . . . . . . . . . . . . . . . IN–8
PRECAUTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IN–8
HOW TO TROUBLESHOOT
ECU CONTROLLED SYSTEMS . . . . . . . . . IN–9
GENERAL INFORMATION . . . . . . . . . . . . . . . . . . IN–9
HOW TO PROCEED
WITH TROUBLESHOOTING . . . . . . . . . . . . . . IN–10
HOW TO USE THE DIAGNOSTIC CHART
AND INSPECTION PROCEDURE . . . . . . . . . . IN–20
TERMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IN–25
ABBREVIATIONS USED IN THIS MANUAL . . . . IN–25
 IN–1
INTRODUCTION – HOW TO USE THIS MANUAL

HOW TO USE THIS MANUAL

IN04V–03

GENERAL INFORMATION
1. INDEX
An INDEX is provided on the first page of each section to guide you to the item to be repaired. To assist you
in finding your way through the manual, the section title and major heading are given at the top of every page.
2. PRECAUTION
At the beginning of each section, a PRECAUTION is given that pertains to all repair operations contained
in that section.
Read these precautions before starting any repair task.
3. TROUBLESHOOTING
TROUBLESHOOTING tables are included for each system to help you diagnose the problem and find the
cause. The fundamentals of how to proceed with troubleshooting are described on page IN–9.
Be sure to read this before performing troubleshooting.
4. PREPARATION
Preparation lists the SST (Special Service Tools), recommended tools, equipment, lubricant and SSM (Spe-
cial Service Materials) which should be prepared before beginning the operation and explains the purpose
of each one.
5. REPAIR PROCEDURES
Most repair operations begin with an overview illustration. It identifies the components and shows how the
parts fit together.
Example:

Driven Rotor

z Crankshaft Front Oil Seal

Relief Valve

Spring

z Gasket
Plug
49 (500, 36)

N·m (kgf·cm, ft·lbf) : Specified torque B07996

z Non–reusable part B08237

IN–2
INTRODUCTION – HOW TO USE THIS MANUAL

The procedures are presented in a step–by–step format:

S The illustration shows what to do and where to do it.
S The task heading tells what to do.
S The detailed text tells how to perform the task and gives other information such as specifications
and warnings.
Example:
Task heading : what to do

21. CHECK PISTON STROKE OF OVERDRIVE BRAKE

(a) Place SST and a dial indicator onto the overdrive brake pis-
ton as shown in the illustration.
SST 09350–30020 (09350–06120)
Illustration:
what to do and where Set part No. Component part No.
Detailed text : how to do task
(b) Measure the stroke applying and releasing the compressed
air (392 Ċ 785 kPa, 4 Ċ 8 kgf/cm 2 or 57 Ċ 114 psi) as shown
in the illustration.
Piston stroke: 1.40 Ċ 1.70 mm (0.0551 Ċ 0.0669 in.)
Specification
This format provides the experienced technician with a FAST TRACK to the information needed. The upper
case task heading can be read at a glance when necessary, and the text below it provides detailed informa-
tion. Important specifications and warnings always stand out in bold type.
6. REFERENCES
References have been kept to a minimum. However, when they are required you are given the page to refer
to.
7. SPECIFICATIONS
Specifications are presented in bold type throughout the text where needed. You never have to leave the
procedure to look up your specifications. They are also found in Service Specifications section for quick ref-
erence.
8. CAUTIONS, NOTICES, HINTS:
S CAUTIONS are presented in bold type, and indicate there is a possibility of injury to you or other
people.
S NOTICES are also presented in bold type, and indicate the possibility of damage to the components
being repaired.
S HINTS are separated from the text but do not appear in bold. They provide additional information to
help you perform the repair efficiently.
9. SI UNIT
The UNITS given in this manual are primarily expressed according to the SI UNIT (International System of
Unit), and alternately expressed in the metric system and in the English System.
Example:
Torque: 30 N·m (310 kgf·cm, 22 ft·lbf)
 IN–3
INTRODUCTION – IDENTIFICATION INFORMATION

IDENTIFICATION INFORMATION IN0E6–01

ENGINE SERIAL NUMBER

The engine serial number is stamped on the engine block, as
shown in the illustration.

B07988
IN–4
INTRODUCTION – REPAIR INSTRUCTIONS

REPAIR INSTRUCTIONS IN0E7–01

GENERAL INFORMATION
BASIC REPAIR HINT
(a) Use fender, seat and floor covers to keep the vehicle
clean and prevent damage.
(b) During disassembly, keep parts in the appropriate order
to facilitate reassembly.
P23717
(c) Observe the following operations:
(1) Before performing electrical work, disconnect the
negative (–) terminal cable from the battery.
(2) If it is necessary to disconnect the battery for in-
spection or repair, always disconnect the negative
(–) terminal cable which is grounded to the vehicle
body.
(3) To prevent damage to the battery terminal, loosen
the cable nut and raise the cable straight up without
twisting or prying it.
(4) Clean the battery terminals and cable ends with a
clean shop rag. Do not scrape them with a file or oth-
er abrasive objects.
(5) Install the cable ends to the battery terminals with
the nut loose, and tighten the nut after installation.
Do not use a hammer to tap the cable ends onto the
terminals.
(6) Be sure the cover for the positive (+) terminal is
properly in place.
(d) Check hose and wiring connectors to make sure that they
are secure and correct.
(e) Non–reusable parts
(1) Always replace cotter pins, gaskets, O–rings and oil
seals etc. with new ones.
(2) Non–reusable parts are indicated in the component
illustrations by the ”z” symbol.
(f) Precoated parts
Precoated parts are bolts and nuts, etc. that are coated
with a seal lock adhesive at the factory.
(1) If a precoated part is retightened, loosened or
caused to move in any way, it must be recoated with
the specified adhesive.
(2) When reusing precoated parts, clean off the old
adhesive and dry with compressed air. Then apply
the specified seal lock adhesive to the bolt, nut or
threads.
(3) Precoated parts are indicated in the component il-
lustrations by the ”L” symbol.
(g) When necessary, use a sealer on gaskets to prevent
leaks.
 IN–5
INTRODUCTION – REPAIR INSTRUCTIONS

(h) Carefully observe all specifications for bolt tightening

torques. Always use a torque wrench.
(i) Use of special service tools (SST) and special service ma-
terials (SSM) may be required, depending on the nature
of the repair. Be sure to use SST and SSM where speci-
fied and follow the proper work procedure. A list of SST
and SSM can be found in section PP (Preparation) in this
manual.

(j) When replacing fuses, be sure the new fuse has the cor-
Medium Current Fuse and High Current Fuse
rect amperage rating. DO NOT exceed the rating or use
Equal Amperage Rating
one with a lower rating.

BE1367

Illustration Symbol Part Name Abbreviation

FUSE FUSE

MEDIUM CURRENT FUSE M–FUSE

HIGH CURRENT FUSE H–FUSE

FUSIBLE LINK FL

CIRCUIT BREAKER CB

V00076

(k) Care must be taken when jacking up and supporting the

vehicle. Be sure to lift and support the vehicle at the prop-
er locations.
S Cancel the parking brake on the level place and
shift the transmission in Neutral (or N position).
S When jacking up the front wheels of the vehicle at
first place stoppers behind the rear wheels.
S When jacking up the rear wheels of the vehicle at
first place stoppers behind the rear wheels.
IN–6
INTRODUCTION – REPAIR INSTRUCTIONS

S When either the front or rear wheels only should be

jacked up, set rigid racks and place stoppers in front
and behind the other wheels on the ground.
S After the vehicle is jacked up, be sure to support it
on rigid racks. It is extremely dangerous to do any
work on a vehicle raised on a jack alone, even for
a small job that can be finished quickly.
(l) Observe the following precautions to avoid damage to the
following parts:
(1) Do not open the cover or case of the ECU unless
absolutely necessary. (If the IC terminals are
touched, the IC may be destroyed by static electric-
ity.)

(2) To disconnect vacuum hoses, pull off the end, not

WRONG CORRECT the middle of the hose.

IN0253

(3) To pull apart electrical connectors, pull on the con-

WRONG CORRECT nector itself, not the wires.
(4) Be careful not to drop electrical components, such
as sensors or relays. If they are dropped on a hard
floor, they should be replaced and not reused.
(5) When steam cleaning an engine, protect the elec-
tronic components, air filter and emission–related
components from water.
IN0252 (6) Never use an impact wrench to remove or install
temperature switches or temperature sensors.
(7) When checking continuity at the wire connector, in-
sert the tester probe carefully to prevent terminals
from bending.
(8) When using a vacuum gauge, never force the hose
onto a connector that is too large. Use a step–down
adapter for adjustment. Once the hose has been
stretched, it may leak.
 IN–7
INTRODUCTION – REPAIR INSTRUCTIONS

Example
(m) Tag hoses before disconnecting them:
(1) When disconnecting vacuum hoses, use tags to
identify how they should be reconnected.
(2) After completing a job, double check that the vacu-
um hoses are properly connected. A label under the
hood shows the proper layout.
(n) Unless otherwise stated, all resistance is measured at an
ambient temperature of 20°C (68°F). Because the resis-
IN0002 tance may be outside specifications if measured at high
temperatures immediately after the vehicle has been run-
ning, measurement should be made when the engine has
cooled down.
IN–8
INTRODUCTION – FOR ALL OF VEHICLES

FOR ALL OF VEHICLES

IN0E8–01

PRECAUTION
1. FOR VEHICLES EQUIPPED WITH A CATALYTIC CONVERTER
CAUTION:
If large amount of unburned gasoline flows into the converter, it may overheat and create a fire haz-
ard. To prevent this, observe the following precautions and explain them to your customer.
(a) Use only unleaded gasoline.
(b) Avoid prolonged idling.
Avoid running the engine at idle speed for more than 20 minutes.
(c) Avoid spark jump test.
(1) Perform spark jump test only when absolutely necessary. Perform this test as rapidly as possible.
(2) While testing, never race the engine.
(d) Avoid prolonged engine compression measurement.
Engine compression tests must be done as rapidly as possible.
(e) Do not run engine when fuel tank is nearly empty.
This may cause the engine to misfire and create an extra load on the converter.
(f) Avoid coasting with ignition turned off and prolonged braking.
(g) Do not dispose of used catalyst along with parts contaminated with gasoline or oil.
2. IF VEHICLE IS EQUIPPED WITH MOBILE COMMUNICATION SYSTEM
For vehicles with mobile communication systems such as two–way radios and cellular telephones, observe
the following precautions.
(1) Install the antenna as far as possible away from the ECU and sensors of the vehicle’s electronic
system.
(2) Install the antenna feeder at least 20 cm (7.87 in.) away from the ECU and sensors of the ve-
hicle’s electronic systems. For details about ECU and sensors locations, refer to the section on
the applicable component.
(3) Avoid winding the antenna feeder together with the other wiring as much as possible, and also
avoid running the antenna feeder parallel with other wire harnesses.
(4) Check that the antenna and feeder are correctly adjusted.
(5) Do not install powerful mobile communications system.
3. FOR USING HAND–HELD TESTER
CAUTION:
Observe the following items for safety reasons:
S Before using the hand–held tester, the hand–held tester’s operator manual should be read
throughly.
S Be sure to route all cables securely when driving with the hand–held tester connected to the
vehicle. (i.e. Keep cables away from feet, pedals, steering wheel and shift lever.)
S Two persons are required when test driving with the hand–held tester, one person to drive the
vehicle and one person to operate the hand–held tester.
 INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED IN–9
SYSTEMS

HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS

IN050–03

GENERAL INFORMATION
A large number of ECU controlled systems are used in the AVENSIS/CORONA. In general, the ECU con-
trolled system is considered to be a very intricate system requiring a high level of technical knowledge and
expert skill to troubleshoot. However, the fact is that if you proceed to inspect the circuits one by one, trouble-
shooting of these systems is not complex. If you have adequate understanding of the system and a basic
knowledge of electricity, accurate diagnosis and necessary repair can be performed to locate and fix the
problem. This manual is designed through emphasis of the above standpoint to help service technicians
perform accurate and effective troubleshooting, and is compiled for the following major ECU controlled sys-
tems:
System Page
Engine DI–1

The troubleshooting procedure and how to make use of it are described on the above pages.
FOR USING HAND–HELD TESTER
S Before using the hand–held tester, the hand held–tester’s operator manual should be read throughly.
S If the hand–held tester cannot communicate with ECU controlled systems when you have connected
the cable of the hand–held tester to DLC3, turned the ignition switch ON and operated the scan tool,
there is a problem on the vehicle side or tool side.
(1) If communication is normal when the tool is connected to another vehicle, inspect the diagnosis
data link line (Busęline) or ECU power circuit of the vehicle.
(2) If communication is still not possible when the tool is connected to another vehicle, the problem
is probably in the tool itself, so perform the Self Test procedures outlined in the Tester Operator’s
Manual.
IN–10 INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
IN051–03

HOW TO PROCEED WITH TROUBLESHOOTING

Carry out troubleshooting in accordance with the procedure on the following page. Here, only the basic pro-
cedure is shown. Details are provided in each section, showing the most effective methods for each circuit.
Confirm the troubleshooting procedures first for the relevant circuit before beginning troubleshooting of that
circuit.

Vehicle Brought to Workshop

1
1 Customer Problem Ask the customer about the conditions and the
Analysis environment when the problem occurred.

2 Symptom Confirmation 3
and Diagnostic Trouble Symptom Simulation
Code Check
2, 3
Confirm the symptoms and the problem conditions,
and check the diagnostic trouble codes.
(When the problem symptoms do not appear
during confirmation, use the symptom simulation
method described later on.)
4 Diagnostic Trouble
Code Chart

5
Problem Symptoms Table

4, 5, 6
Check the results obtained in Step 2, then confirm
the inspection procedure for the system or the part
which should be checked using the diagnostic
6 trouble code chart or the problem symptoms table.
Circuit Inspection or Parts
Inspection

7
7 Repair Check and repair the affected system or part in
accordance with the instructions in Step 6.

8
8 Confirmation Test
After completing repairs, confirm that the problem
has been eliminated.
(If the problem is not reproduced, perform the
confirmation test under the same conditions and
End
in the same environment as when it occurred for
the first time.)
 INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED IN–11
SYSTEMS

1. CUSTOMER PROBLEM ANALYSIS

In troubleshooting, the problem symptoms must be confirmed accurately and all preconceptions must be
cleared away in order to give an accurate judgement. To ascertain just what the problem symptoms are, it
is extremely important to ask the customer about the problem and the conditions at the time it occurred.
Important Point in the Problem Analysis:
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, so as much information as possible should
be gathered and its relationship with the problem symptoms should be correctly ascertained for reference
in troubleshooting. A customer problem analysis table is provided in the troubleshooting section for each
system for your use.
Important Points in the Customer Problem Analysis
D What ––––– Vehicle model, system name
D When ––––– Date, time, occurrence frequency
D Where ––––– Road conditions
D Under what conditions? ––––– Running conditions, driving conditions, weather conditions
D How did it happen? ––––– Problem symptoms

(Sample) Engine control system check sheet.

CUSTOMER PROBLEM ANALYSIS CHECK

Inspector’s
ENGINE CONTROL SYSTEM Check Sheet Name

Customer’s Name Model and Model

Year

Driver’s Name Frame No.

Data Vehicle
Brought in Engine Model

km
License No. Odometer Reading miles

Engine does Engine does not crank No initial combustion No complete combustion
not Start

Difficult to Engine cranks slowly

Start Other
Problem Symptoms

Incorrect first idle Idling rpm is abnormal High ( rpm) Low ( rpm)
Poor Idling
Rough idling Other

Poor Hesitation Back fire Muffler explosion (after–fire) Surging

Drive ability Knocking Other

Soon after starting After accelerator pedal depressed

Engine Stall After accelerator pedal released During A/C operation
Shifting from N to D Other

Others

Datas Problem

Constant Sometimes ( times per day/month)

IN–12 INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS

2. SYMPTOM CONFIRMATION AND DIAGNOSTIC TROUBLE CODE CHECK

The diagnostic system in the AVENSIS/CORONA fulfills various functions. The first function is the Diagnostic
Trouble Code Check in which a malfunction in the signal circuits to the ECU is stored in code in the ECU
memory at the time of occurrence, to be output by the technician during troubleshooting. 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, the problem areas can be narrowed down quickly and troubleshooting can
be performed effectively. Diagnostic functions are incorporated in the following systems in the AVENSIS/CO-
RONA.
Diagnostic Trouble Input Signal Check Other Diagnosis
System
Code Check (Sensor Check) Function

Engine f f Diagnostic Test

(with Test Mode) Mode

In diagnostic trouble code check, it is very important to determine whether the problem indicated by the diag-
nostic trouble code is still occurring or occurred in the past but returned to normal at present. In addition,
it must be checked in the problem symptom check whether the malfunction indicated by the diagnostic
trouble code is directly related to the problem symptom or not. For this reason, the diagnostic trouble codes
should be checked before and after the symptom confirmation to determine the current conditions, as shown
in the table below. If this is not done, it may, depending on the case, result in unnecessary troubleshooting
for normally operating systems, thus making it more difficult to locate the problem, or in repairs not pertinent
to the problem. Therefore, always follow the procedure in correct order and perform the diagnostic trouble
code check.

DIAGNOSTIC TROUBLE CODE CHECK PROCEDURE

Diagnostic Trouble
Confirmation Diagnostic Trouble
Code Check (Make a Problem Condition
of Symptoms Code Check
note of and then clear)
Diagnostic Trouble Problem symptoms Same diagnostic Problem is still occurring in the diagnostic
Code Display exist trouble code is circuit
displayed

Normal code is The problem is still occurring in a place

displayed other than in the diagnostic circuit
(The diagnostic trouble code displayed
first is either for a past problem or it is a
secondary problem)

No problem The problem occurred in the diagnostic

symptoms exist circuit in the past
Normal Code Display Problem symptoms Normal code is The problem is still occurring in a place
exist displayed other than in the diagnostic circuit
No problem Normal code is The problem occurred in a place other
symptoms exist displayed than in the diagnostic circuit in the past
 INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED IN–13
SYSTEMS

Taking into account the above points, a flow chart showing how to proceed with troubleshooting using the
diagnostic trouble code check is shown below. This flow chart shows how to utilize the diagnostic trouble
code check effectively, then by carefully checking the results, indicates how to proceed either to diagnostic
trouble code troubleshooting or to troubleshooting of problem symptoms.

Diagnostic trouble code check

Making a note of and clearing of the diagnostic trouble codes displayed

Symptom confirmation
Problem symptoms No problem symptoms
exist exist

Simulation test using the symptom

simulation methods

Diagnostic trouble code check

D Diagnostic trouble code displayed D Normal code displayed D Normal code displayed
D Problem symptoms exist D Problem symptoms exist D No problem symptoms exist

Troubleshooting of problem indicated Troubleshooting of each System Normal

by diagnostic trouble code problem symptom
If a diagnostic trouble code was
displayed in the initial diagnostic
trouble code check, it indicates
that the trouble may have occurred
in a wire harness or connector in
that circuit in the past. Therefore,
check the wire harness and con-
nectors (See page IN–20).
IN–14 INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS

3. SYMPTOM SIMULATION
The most difficult case in troubleshooting is when there are no problem symptoms occurring. In such cases,
a thorough customer problem analysis must be carried out, then simulate the same or similar conditions and
environment in which the problem occurred in the customer’s vehicle. No matter how much experience a
technician 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 en-
gine is cold, or for a problem which occurs due to vibration caused by the road during driving, etc., the prob-
lem can never be determined so long as the symptoms are confirmed with the engine hot condition or the
vehicle at a standstill. Since vibration, heat or water penetration (moisture) is likely cause for problem which
is difficult to reproduce, the symptom simulation tests introduced here are effective measures in that the ex-
ternal causes are applied to the vehicle in a stopped condition.
Important Points in the Symptom Simulation Test:
In the symptom simulation test, the problem symptoms should of course be confirmed, but the problem area
or parts must also be found out. To do this, narrow down the possible problem circuits according to the symp-
toms before starting this test and connect a tester beforehand. After that, carry out the symptom simulation
test, judging whether the circuit being tested is defective or normal and also confirming the problem symp-
toms at the same time. Refer to the problem symptoms table for each system to narrow down the possible
causes of the symptom.

1 VIBRATION METHOD: When vibration seems to be the major cause.

CONNECTORS
Slightly shake the connector vertically and horizontally.

Shake Slightly

WIRE HARNESS
Slightly shake the wire harness vertically and horizontally.
The connector joint, fulcrum of the vibration, and body
through portion are the major areas to be checked thorough-
ly.

Swing Slightly

PARTS AND SENSOR Vibrate Slightly

Apply slight vibration with a finger to the part of the sensor
considered to be the problem cause and check that the
malfunction occurs.
HINT: Applying strong vibration to relays may result in open
relays.

V07268
 INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED IN–15
SYSTEMS

2 HEAT METHOD: When the problem seems to occur when the suspect area is heated.

Heat the component that is the likely cause of the malfunction

with a hair dryer or similar object. Check to see if the malfunction
occurs. M a l f u n c-
tion
NOTICE:
(1) Do not heat to more than 60°C (140°F). (Temperature
is limited not to damage the components.)
(2) Do not apply heat directly to parts in the ECU.

3 WATER SPRINKLING METHOD: When the malfunction seems to occur on a rainy day or in a
high–humidity condition.
Sprinkle water onto the vehicle and check to see if the malfunc-
tion occurs.
NOTICE:
(1) Never sprinkle water directly into the engine
compartment, but indirectly change the temperature and
humidity by applying water spray onto the radiator front
surface.
(2) Never apply water directly onto the electronic
components.
HINT:
If a vehicle is subject to water leakage, the leaked water may
contaminate the ECU. When testing a vehicle with a water leak-
age problem, special caution must be taken.

4 OTHER: When a malfunction seems to occur when electrical load is excessive.

Turn on all electrical loads including the heater blower, head ON

lights, rear window defogger, etc. and check to see if the mal-
function occurs.

V07469
IN–16 INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS

4. DIAGNOSTIC TROUBLE CODE CHART

The inspection procedure is shown in the table below. This table permits efficient and accurate troubleshoot-
ing using the diagnostic trouble codes displayed in the diagnostic trouble code check. Proceed with trouble-
shooting in accordance with the inspection procedure given in the diagnostic chart corresponding to the
diagnostic trouble codes displayed. The engine diagnostic trouble code chart is shown below as an example.

D DTC No.
Indicates the diagnostic trouble code.
D Page or Instructions
Indicates the page where the inspection procedure D Trouble Area
for each circuit is to be found, or gives instructions Indicates the suspect area of the
for checking and repairs. problem.

D Detection Item
Indicates the system of the problem or
contents of the problem.

DIAGNOSTIC TROUBLE CODE CHART

HINT:
Parameters listed in the chart may not be exactly the same as your reading due to the type of instrument or other
factors.
If a malfunction code is displayed during the DTC check in check (test) mode, check the circuit for that code
listed in the table below. For details of each code, turn to the page referred to under the ”See page” for the
respective ”DTC No.” in the DTC chart.
*1
Check Engine
DTC No. Warming Light
*2
Detection Item Trouble Area Memory
(See page) Normal Mode/
Test Node

D Open or short in crankshaft position sensor circuit

12 Crankshaft Position Sensor Circuit
D Crankshaft position sensor ON / N.A
(DI – 12) Malfunction
D Engine ECU
D Open or short in engine speed sensor circuit
13 Engine Speed Sensor Circuit D Engine speed sensor
(DI – 28) ON / N.A
Malfunction D Engine ECU

D Open or short in E–VRV for main actuator circuit

D E–VRV for main actuator
15 Diesel Throttle Control Circuit D Diesel throttle position sensor circuit
D Diesel throttle position sensor ON / N.A
(DI – 32) Malfunction
D Main actuator
D Vacuum hose disconnected or blocked
D Engine ECU

Interior IC Malfunction D Engine ECU

 INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED IN–17
SYSTEMS

5. PROBLEM SYMPTOMS TABLE

The suspect circuits or parts for each problem symptom are shown in the table below. Use this table to trou-
bleshoot the problem when a ”Normal” code is displayed in the diagnostic trouble code check but the prob-
lem is still occurring. Numbers in the table indicate the inspection order in which the circuits or parts should
be checked.
HINT:
When the problem is not detected by the diagnostic system even though the problem symptom is present,
it is considered that the problem is occurring outside the detection range of the diagnostic system, or that
the problem is occurring in a system other than the diagnostic system.

D Page
Indicates the page where the flow chart for each circuit
is located.

D Circuit Inspection, Inspection Order

Indicates the circuit which needs to be checked for each problem
symptom. Check in the order indicated by the numbers.

D Circuit or Part Name

D Problem Symptom Indicates the circuit or part which needs to be checked.

PROBLEM SYMPTOMS TABLE

Symptom Suspect Area See page

1. Starter ST–3
Engine does not crank (Does not start)
2. Starter relay ST–14
1. ECU power source circuit DI–93
No initial combustion (Does not start) 2. Pre–heating system ST–1
3. Compression EM–2
4. Engine ECU IN–20
1. Pre–heating system ST–1
2. Starter signal circuit DI–115
3. Water temperature sensor ED–10
Cold engine (Difficult to start) 4. Injector
5. Fuel filter FU–1
6. Diesel throttle body DI–26
7. Engine ECU IN–20
1. Starter signal circuit DI–115
2. Injector
Hot engine 3. Fuel filter
4. Diesel throttle body
7 Engine ECU
1. Fuel filter
2. Diesel throttle body
3 Engine ECU
IN–18 INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS

6. CIRCUIT INSPECTION
How to read and use each page is shown below.

D Diagnostic Trouble Code No. and Detection Item

D Circuit Description
The major role and operation, etc. of the circuit
and its component parts are explained.

DTC 12 Crankshaft Position Sensor Circuit Malfunc-

tion
CIRCUIT DESCRIPTION
The crankshaft position sensor in the Engine Control System contains signal plate and a pickup coil for TDC signal.
The TDC signal plate has 1 tooth on its outer circumference. The TDC signal sensor generates 1 signal for every engine
revolution. The engine ECU detects the top dead center by the TDC signals. The NE signal plate has 52 teeth and is
mounted in the supply pump. The NE signal sensor generates 52 signals of engine 2 revolutions. The engine ECU detects
the engine speed and cam lift position of the supply pump. The engine ECU uses TDC signal and NE signals for injection
control. And NE signal is used for injection volume control, also.
DTC No. DTC Detecting Condition Trouble Area
D Open or short in crankshaft position sensor

12 circuit
No TDC signal to engine ECU at 500 rpm or more
D Crankshaft position sensor
D Engine ECU

D Indicates the diagnostic trouble code, diagnostic

trouble code set parameter and suspect area of
the problem.

WIRING DIAGRAM D Wiring Diagram

This shows a wiring diagram of the circuit.
Engine ECU Use this diagram together with ELECTRICAL
Crankshaft Position Sensor WIRING DIAGRAM to thoroughly understand the
6
1 B–W
E7
G22+ circuit.
Wire colors are indicated by an alphabetical code.
2 L B = Black, L = Blue, R = Red, BR = Brown,
LG = Light Green, V = Violet, G = Green,
1 B–R B–R
5 NE+ O = Orange, W = White, GR = Gray, P = Pink,
E7
Y = Yellow
2 BR L
6 The first letter indicates the basic wire color and the
E7
NE– second letter indicates the color of the stripe.
Engine Speed Sensor E2

(inside the Suppy Pump)

B02134
 INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED IN–19
SYSTEMS

D Indicates the position of the ignition switch during the check. D Inspection Procedure
LOCK ON Use the inspection procedure to determine
Ignition Switch LOCK (OFF) Ignition Switch ON if the circuit is normal or abnormal, and if
START ACC
it is abnormal, use it to determine whether
Ignition Switch ACC the problem is located in the sensors,
Ignition Switch START
actuators, wire harness or ECU.

INSPECTION PROCEDURE

1 Check continuity between terminal THW of ECU connector and body ground.

LOCK PREPARATION:
THW (a) Remove the glove compartment.
(b) Disconnect the E6 connector of ECU.
CHECK:
Measure resistance between terminal THW of ECU connector
and body ground.
E6 Connector OK:
AB0117 Resistance: 1 MΩ or higher
A00265 A00255

OK Go to step 3.

NG

2 Check water temp. sensor (See page ED–10).

OK Replace water temp. sensor.

D Indicates the place to check the voltage or resistance.

D Indicates the connector position to be checked, from the front or back side.

Wire Harness

Check from the connector back side. Check from the connector front side. (without harness)
(with harness) In this case, care must be taken not to bend the terminals.

D Indicates the condition of the connector of ECU during the check.

TWH THW

E6 Connector E6 Connector

Connector being checked is connected. Connector being checked is disconnected.

V08425
IN–20 INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
IN052–03

HOW TO USE THE DIAGNOSTIC

CHART AND INSPECTION
PROCEDURE
1. CONNECTOR CONNECTION AND TERMINAL IN-
SPECTION
S For troubleshooting, diagnostic trouble code charts or
problem symptom charts are provided for each circuit with
FI0046 detailed inspection procedures on the following pages.
S When all the component parts, wire harnesses and con-
nectors of each circuit except the ECU are found to be
normal in troubleshooting, then it is determined that the
problem is in the ECU. Accordingly, if diagnosis is per-
formed without the problem symptoms occurring, refer to
step 8 to replace the ECU, even if the problem is not in the
ECU. So always confirm that the problem symptoms are
occurring, or proceed with inspection while using the
symptom simulation method.
FI0047 S The instructions ”Check wire harness and connector” and
”Check and replace ECU” which appear in the inspection
procedure, are common and applicable to all diagnostic
trouble codes. Follow the procedure outlined below
whenever these instructions appear.
OPEN CIRCUIT:
This could be due to a disconnected wire harness, faulty con-
tact in the connector, and a connector terminal pulled out, etc.
HINT:
S It is rarely the case that a wire is broken in the middle of
FI0048 it. Most cases occur at the connector. In particular, care-
fully check the connectors of sensors and actuators.
S Faulty contact could be due to rusting of the connector
terminals, to foreign materials entering terminals or a de-
formation of connector terminals. Simply disconnecting
and reconnecting the connectors once changes the
condition of the connection and may result in a return to
normal operation. Therefore, in troubleshooting, if no ab-
normality is found in the wire harness and connector
check, but the problem disappears after the check, then
the cause is considered to be in the wire harness or con-
nectors.
SHORT CIRCUIT:
This could be due to a contact between wire harness and the
body ground or to a short circuit occurred inside the switch, etc.
HINT:
When there is a short circuit between the wire harness and body
ground, check thoroughly whether the wire harness is caught
in the body or is clamped properly.
 INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED IN–21
SYSTEMS

Sensor Side 2. CONTINUITY CHECK (OPEN CIRCUIT CHECK)

ECU Side (a) Disconnect the connectors at both ECU and sensor
sides.
(b) Measure the resistance between the applicable terminals
of the connectors.
Resistance: 1Ω or less
HINT:
S Measure the resistance while lightly shaking the wire har-
IN0379 ness vertically and horizontally.
S When tester probes are inserted into a connector, insert
ECU Side the probes from the back. For waterproof connectors in
which the probes cannot be inserted from the back, be
careful not to bend the terminals when inserting the tester
Sensor Side
probes.

IN0378

ECU Side 3. RESISTANCE CHECK (SHORT CIRCUIT CHECK)

(a) Disconnect the connectors on both ends.
(b) Measure the resistance between the applicable terminals
Sensor Side
of the connectors and body ground. Be sure to carry out
this check on the connectors on both ends.
Resistance: 1 MΩ or higher
HINT:
Measure the resistance while lightly shaking the wire harness
IN0380 vertically and horizontally.

4. VISUAL CHECK AND CONTACT PRESSURE CHECK

(a) Disconnect the connectors at both ends.
(b) Check for rust or foreign material, etc. in the terminals of
the connectors.
Pull Lightly (c) Check crimped portions for looseness or damage and
Looseness of Crimping check that the terminals are secured in lock portion.
HINT:
The terminals should not come out when pulled lightly.
IN0381 (d) Prepare a test male terminal and insert it in the female ter-
minal, then pull it out.
NOTICE:
When testing a gold–plated female terminal, always use a
gold–plated male terminal.
HINT:
When the test terminal is pulled out more easily than others,
there may be poor contact in that section.
IN–22 INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS

5. CONNECTOR HANDLING
When inserting tester probes into a connector, insert them from
the rear of the connector. When necessary, use mini test leads.
For water resistant connectors which cannot be accessed from
behind, take good care not to deform the connector terminals.

FI7187

6. CHECK OPEN CIRCUIT

Fig. 1 ECU For the open circuit in the wire harness in Fig. 1, perform ”(a)
C OPEN B A Continuity Check” or ”(b) Voltage Check” to locate the section.
Sensor 1 1 1 1
2 2 2 2

Z17004

(a) Check the continuity.

Fig. 2 (1) Disconnect connectors ”A” and ”C” and measure
the resistance between them.
ECU In the case of Fig. 2,
C A Between terminal 1 of connector ”A” and terminal 1
Sensor 1 B1 1
2 2 2 of connector ”C” → No continuity (open)
Between terminal 2 of connector ”A” and terminal 2
of connector ”C” → Continuity
Z17005 Therefore, it is found out that there is an open circuit
between terminal 1 of connector ”A” and terminal 1
Fig. 3 of connector ”C”.
(2) Disconnect connector ”B” and measure the resis-
ECU tance between the connectors.
In the case of Fig. 3,
Sensor
Between terminal 1 of connector ”A” and terminal 1
C B2 B1 A of connector ”B1” → Continuity
1 1 1 1 Between terminal 1 of connector ”B2” and terminal
2 2 2 2 1 of connector ”C” → No continuity (open)
B04722 Therefore, it is found out that there is an open circuit
between terminal 1 of connector ”B2” and terminal
1 of connector ”C”.
 INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED IN–23
SYSTEMS

Fig. 4 (b) Check the voltage.

In a circuit in which voltage is applied (to the ECU connec-
tor terminal), an open circuit can be checked for by con-
5V ECU ducting a voltage check.
0V
5V A 5V As shown in Fig. 4, with each connector still connected,
Sensor C 1 B 1 1
measure the voltage between body ground and terminal
2 2 2
1 of connector ”A” at the ECU 5V output terminal, terminal
1 of connector ”B”, and terminal 1 of connector ”C”, in that
Z17007 order.
If the results are:
5V: Between Terminal 1 of connector ”A” and Body Ground
5V: Between Terminal 1 of connector ”B” and Body Ground
0V: Between Terminal 1 of connector ”C” and Body Ground
Then it is found out that there is an open circuit in the wire har-
ness between terminal 1 of ”B” and terminal 1 of ”C”.

7. CHECK SHORT CIRCUIT

Fig. 5 ECU If the wire harness is ground shorted as in Fig. 5, locate the sec-
C B A tion by conducting a ”continuity check with ground”.
Sensor SHORT 1 1
1
2 2 2

Z17008

Fig. 6 Check the continuity with ground.

(1) Disconnect connectors ”A” and ”C” and measure
the resistance between terminal 1 and 2 of connec-
ECU tor ”A” and body ground.
Sensor C B A In the case of Fig. 6
1 1 1 Between terminal 1 of connector ”A” and body
2 2 2
ground → Continuity (short)
Between terminal 2 of connector ”A” and body
Z17009 ground → No continuity
Therefore, it is found out that there is a short circuit
between terminal 1 of connector ”A” and terminal 1
of connector ”C”.
IN–24 INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS

Fig. 7 (2) Disconnect connector ”B” and measure the resis-

tance between terminal 1 of connector ”A” and body
ground, and terminal 1 of connector ”B2” and body
ground.
ECU Between terminal 1 of connector ”A” and body
C B2 B1 A
Sensor 1 1 1 1 ground → No continuity
2 2 2 2 Between terminal 1 of connector ”B2” and body
ground → Continuity (short)
Z17808 Therefore, it is found out that there is a short circuit
between terminal 1 of connector ”B2” and terminal
1 of connector ”C”.
8. CHECK AND REPLACE ECU
First check the ECU ground circuit. If it is faulty, repair it. If it is
normal, the ECU could be faulty, so replace the ECU with a nor-
mal functioning one and check that the symptoms appear.

Example (1) Measure the resistance between the ECU ground

terminal and the body ground.
Resistance: 1 Ω or less
Ground

IN0383

ECU Side (2) Disconnect the ECU connector, check the ground
terminals on the ECU side and the wire harness
side for bend and check the contact pressure.

Ground
W/H Side

Ground
IN0384
 IN–25
INTRODUCTION – TERMS

TERMS
IN00S–13

ABBREVIATIONS USED IN THIS MANUAL

Abbreviations Meaning
A/C Air Conditioning
AC Alternating Current
ACC Accessory
ACIS Acoustic Control Induction System
ACSD Automatic Cold Start Device
ALT Alternator
AMP Amplifier
APROX. Approximately
A/T Automatic Transmission (Transaxle)
BACS Boost Altitude Compensation System
BAT Battery
BTDC Before Top Dead Center
BVSV Bimetallic Vacuum Switching Valve
CB Circuit Breaker
CCO Catalytic Converter for Oxidation
DC Direct Current
DLC Data Link Connector
DTC Diagnostic Trouble Code
ECD Electronic Control Diesel
ECT Electronic Control Transmission
ECU Electronic Control Unit
EDU Electronic Driving Unit
EFI Electronic Fuel Injection
E/G Engine
EGR Exhaust Gas Recirculation
EVAP Evaporative Emission Control
E–VRV Electronic Vacuum Regulating Valve
EX Exhaust
FIPG Formed In Place Gasket
FL Fusible Link
Fr Front
GND Ground
HAC High Altitude Compensator
IG Ignition
IIA Integrated Ignition Assembly
IN Intake
ISC Idle Speed Control
J/B Junction Block
J/C Junction Connector
LCD Liquid Crystal Display
LED Light Emitting Diode
LH Left–Hand
IN–26
INTRODUCTION – TERMS

LHD Left–Hand Drive

LO Low
MAP Manifold Absolute Pressure
MAX. Maximum
MIL Malfunction Indicator Lamp
MIN. Minimum
MP Multipurpose
M/T Manual Transmission
N Neutral
O2S Oxygen Sensor
O/D Overdrive
O/S Oversize
PKB Parking Brake
PS Power Steering
RAM Random Access Memory
R/B Relay Block
RH Right–Hand
RHD Right–Hand Drive
ROM Read Only Memory
Rr Rear
SICS Starting Injection Control System
SPEC Specification
SSM Special Service Materials
SST Special Service Tools
STD Standard
SW Switch
TACH Tachometer
TDC Top Dead Center
TEMP. Temperature
TM Transmission
TMC TOYOTA Motor Corporation
TWC Three–Way Catalyst
U/D Underdrive
VCV Vacuum Control Valve
VIN Vehicle Identification Number
VSV Vacuum Switching Valve
w/ With
W/H Wire Harness
w/o Without
WU–TWC Warm Up Three–Way Catalytic Converter
2WD Two Wheel Drive Vehicle (4x2)
4WD For Wheel Drive Vehicle (4x4)