ECU TOYOTA T100 1996 Factory Service Manual

Downloaded from www.Manualslib.com manuals search engine
IN – INTRODUCTION

HOW TO USE THIS MANUAL IN-1
IDENTIFICATION INFORMATION IN-3
REPAIR INSTRUCTIONS IN-4
FOR ALL OF VEHICLES IN-9
HOW TO TROUBLESHOOT ECU
CONTROLLED SYSTEMS IN-15
TERMS IN-31

Downloaded from www.Manualslib.com manuals search engine FI1066
IN0IL−01
Z11554
Seal Lock Adhesive
IN−4
− INTRODUCTIONREPAIR INSTRUCTIONS
4 Author: Date:
1996 TOYOTA T100 (RM449U)
REPAIR INSTRUCTIONS
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.
(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 ”” 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.

Downloaded from www.Manualslib.com manuals search engine IN0253
WRONG CORRECT
IN0252
WRONG CORRECT
IN0002
Example IN−6
− INTRODUCTIONREPAIR INSTRUCTIONS
6 Author: Date:
1996 TOYOTA T100 (RM449U)
(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 (See page IN−8).
(1) If the vehicle is to be jacked up only at the front or
rear end, be sure to block the wheels at the opposite
end in order to ensure safety.
(2) After the vehicle is jacked up, be sure to support it
on stands. 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, ECM,
PCM or TCM unless absolutely necessary. (If the IC
terminals are touched, the IC may be destroyed by
static electricity.)
(2) To disconnect vacuum hoses, pull off the end, not
the middle of the hose.
(3) To pull apart electrical connectors, pull on the con-
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.
(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.
(m) Tag hoses before disconnecting them:
(1) When disconnecting vacuum hoses, use tags to
identify how they should be reconnected to.
(2) After completing a job, double check that the vacu-
um hoses are properly connected. A label under the
hood shows the proper layout.

Downloaded from www.Manualslib.com manuals search engine B01124
Front IN−10
− INTRODUCTIONFOR ALL OF VEHICLES
10 Author: Date:
1996 TOYOTA T100 (RM449U)
(4) Never use SRS parts from another vehicle. When
replacing parts, replace them with new parts.
(5) Before repairs, remove the center airbag sensor if
shocks are likely to be applied to the sensor during
repairs.
(6) Never disassemble and repair the center airbag
sensor assembly, steering wheel pad in order to re-
use it.
(7) If the center airbag sensor assembly, steering
wheel pad have been dropped, or if there are
cracks, dents or other defects in the case, bracket
or connector, replace them with new ones.
(8) Do not expose the center airbag sensor assembly,
steering wheel pad directly to hot air or flames.
(9) Use a volt/ohmmeter with high impedance (10 kΩ/V
minimum) for troubleshooting of the electrical cir-
cuit.
(10) Information labels are attached to the periphery of
the SRS components. Follow the instructions on the
notices.
(11) After work on the supplemental restraint system is
completed, check the SRS warning light (See page
DI−365).
(c) FRONT AIRBAG SENSOR
(1) Never reuse the front airbag sensors involved in a
collision that activated the supplemental restraint
system. (Replace both left and right airbag sen-
sors.)
(2) Install the front airbag sensor with the arrow on the
sensor facing toward the front of the vehicle.
The front airbag sensor set bolts have been anti−
rust treated. When the sensor is removed, always
replace the set bolts with new ones.
(3) The front airbag sensor is equipped with an electri-
cal connection check mechanism. Be sure to lock
this mechanism securely when connecting the con-
nector.
(4) If connector is not securely locked, a malfunction
code will be the diagnosis system (See page
RS−2).

Downloaded from www.Manualslib.com manuals search engine IN−14
− INTRODUCTIONFOR ALL OF VEHICLES
14 Author: Date:
1996 TOYOTA T100 (RM449U)
3. 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 electronics 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) Confirm that the antenna and feeder are correctly adjusted.
(5) Do not install powerful mobile communications system.

Downloaded from www.Manualslib.com manuals search engine IN02I−02
− INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN−15
15 Author: Date:
1996 TOYOTA T100 (RM449U)
HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
GENERAL INFORMATION
A large number of ECU controlled systems are used in the TOYOTA T100. In general, the ECU controlled
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, troubleshoot-
ing of these systems is not complex. If you have adequate understanding of the system and a basic knowl-
edge 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 ac-
curate and effective troubleshooting, and is compiled for the following major ECU controlled systems:
SystemPage
1. 3RZ−FE EngineDI−1
2. 5VZ−FE EngineDI−127
3. Automatic TransmissionDI−263
4. Anti−Lock Brake systemDI−319
5. Supplemental Restraint SystemDI−363
6. Cruise ControlDI−408
The troubleshooting procedure and how to make use of it are described on the above pages.

Downloaded from www.Manualslib.com manuals search engine IN02J−03
Vehicle Brought Workshop
Customer Problem
Analysis
Symptom Confirmation
and Diagnostic Trouble
Code Check
Symptom Simulation
Diagnostic Trouble
Code Chart
Matrix Chart of Problem
Symptoms
Circuit Inspection or Parts
Inspection
Repair
Confirmation Test
End 1
2
43
5
6
7
8Ask the customer about the conditions and the
environment when the problem occurred.1
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.)2, 3
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
trouble code chart or the matrix chart of problem
symptoms.4, 5, 6
Check and repair the affected system or part in
accordance with the instructions in Step 6. 7
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
in the same environment as when it occurred for
the first time.)8
IN−16− INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
1996 TOYOTA T100 (RM449U)
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.

Downloaded from www.Manualslib.com manuals search engine Important Points in the 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) Engine control system check sheet.
ENGINE CONTROL SYSTEM Check Sheet
Customer’s Name
Driver’s Name
Data Vehicle
Brought in
License No.
Model and Model
Year
Frame No.
Engine Model
Odometer Reading
km
miles
Problem Symptoms
Engine does
not Start
Difficult to
Start
Poor Idling
Poor
Drive ability
Engine Stall
Others
Engine does not crankNo initial combustionNo complete combustion
Engine cranks slowly
Other
Incorrect first idleIdling rpm is abnormalHigh ( rpm)Low ( rpm)
Rough idling
Other
HesitationBack fireMuffler explosion (after−fire)Surging
Knocking
Other
Soon after startingAfter accelerator pedal depressed
After accelerator pedal released
During A/C operation
Shifting from N to D
Other
Datas Problem
ConstantSometimes ( times per day/month)
Inspector’s
Name
CUSTOMER PROBLEM ANALYSIS CHECK
− INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN−17
1996 TOYOTA T100 (RM449U)
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.

Downloaded from www.Manualslib.com manuals search engine DIAGNOSTIC TROUBLE CODE CHECK PROCEDURE
Diagnostic Trouble
Code Check (Make a
note of and then clear)Confirmation
of SymptomsDiagnostic Trouble
Code CheckProblem Condition
Diagnostic Trouble
Code DisplayProblem symptoms
existSame diagnostic
trouble code is
displayedProblem is still occurring in the diagnostic
circuit.
Normal code is
displayedThe problem is still occurring in a place
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
symptoms existThe problem occurred in the diagnostic
circuit in the past.
Normal Code DisplayProblem symptoms
existNormal code is
displayedThe problem is still occurring in a place
other than in the diagnostic circuit.
No problem
symptoms existNormal code is
displayedThe problem occurred in a place other
than in the diagnostic circuit in the past.
IN−18− INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
1996 TOYOTA T100 (RM449U)
2. SYMPTOM CONFIRMATION AND DIAGNOSTIC TROUBLE CODE CHECK
The diagnostic system in the TOYOTA T100 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 TOYOTA
T100.
SystemDiagnostic Trouble
Code CheckInput Signal Check
(Sensor Check)Other Diagnosis
Function
Engine (3RZ−FE, 5VZ−FE)
Automatic Transmission
Anti−Lock Brake system
Supplemental Restraint System
Cruise Control (with Test Mode)
 (with Test Mode)






Cancel Signal
Check
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.

Downloaded from www.Manualslib.com manuals search engine Diagnostic trouble code check
Making a note of and clearing of the diagnostic trouble codes displayed
Symptom confirmation
No problem symptoms
exist Problem symptoms
exist
Simulation test using the symptom
simulation methods
 Normal code displayed
 Problem symptoms exist Normal code displayed
 No problem symptoms exist Diagnostic trouble code check
Troubleshooting of problem indicated
by diagnostic trouble code Diagnostic trouble code displayed
 Problem symptoms exist
System Normal Troubleshooting of each
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−26).
− INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN−19
1996 TOYOTA T100 (RM449U)
Taking into account the points on the previous page, a flow chart showing how to proceed with troubleshoot-
ing using the diagnostic trouble code check is shown below. This flow chart shows how to utilize the diagnos-
tic 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.