1996 TOYOTA T100 engine repair

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 − INTRODUCTIONFOR ALL OF VEHICLES
IN−13
13 Author: Date:
1996 TOYOTA T100 (RM449U)
(f) CENTER AIRBAG SENSOR ASSEMBLY
(1) Never reuse the center airbag sensor assembly in-
volved in a collision when the SRS has deployed.
(2) The connectors to the center airbag sensor assem-
bly should be connected or disconnected with the
sensor mounted on the floor. If the connectors are
connected or disconnected while the center airbag
sensor assembly is not mounted to the floor, it could
cause undesired ignition of the supplemental re-
straint system.
(3) Work must be started after 90 seconds from the
time the ignition switch is turned to the ”LOCK” posi-
tion and the negative (−) terminal cable is discon-
nected from the battery, even if only loosening the
set bolts of the center airbag sensor assembly.
(g) WIRE HARNESS AND CONNECTOR
The SRS wire harness is integrated with the cowl wire har-
ness assembly and floor wire harness assembly. The
wires for the SRS wire harness are encased in a yellow
corrugated tube. All the connectors for the system are
also a standard yellow color. If the SRS wire harness be-
comes disconnected or the connector becomes broken
due to an accident, etc., repair or replace it.
2. 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.

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.

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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 V07268
VIBRATION METHOD: When vibration seems to be the major cause.
CONNECTORS
WIRE HARNESS
PARTS AND SENSOR1
Slightly shake the connector vertically and horizontally.
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.
Apply slight vibration with a finger to the part of the sensor
considered to be the problem cause and check if the
malfunction occurs.Shake Slightly
Swing Slightly
Vibrate Slightly
HINT: Applying strong vibration to relays may result in open
relays. IN−20
− INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
1996 TOYOTA T100 (RM449U)
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 matrix chart of problem symptoms for each system to narrow down the
possible causes of the symptom.

Downloaded from www.Manualslib.com manuals search engine  DTC No.
Indicates the diagnostic trouble code.
 Page or Instructions
Indicates the page where the inspection procedure
for each circuit is to be found, or gives instructions
for checking and repairs.
 Detection Item
Indicates the system of the problem or
contents of the problem. Trouble Area
Indicates the suspect area of the
problem.
Mass Air Flow Circuit MalfunctionDetection Item
 Open or short in mass air flow meter circuit
 Mass air flow meter
 ECM DTC No.
(See page)Trouble AreaMIL*MemoryP0100
(DI − 26)
P0101
(DI − 31)Mass Air Flow Circuit
Range/Performance Problem Mass air flow meter
P0115
(DI − 37) Open or short in intake air temp. sensor circuit
 Intake air temp. sensor
 ECM Intake Air Temp. Circuit Malfunction P0110
(DI − 32)
Engine Coolant Temp. Circuit
Range/Performance Problem Open or short in engine coolant temp. sensor circuit
 Engine coolant temp. sensor
 ECM
P0120
(DI − 43)
Throttle/ Pedal Position Sensor/Switch
”A” Circuit Range/Performance
P0116
(DI − 41)
Throttle/Pedal Position Sensor/Switch
”A” Circuit Malfunction
Insufficient Coolant Temp. for Closed Engine coolant temp. sensor
 Cooling system Engine Coolant Temp. Circuit
Malfunction
 Open or short in throttle position sensor circuit
 Throttle position sensor
 ECM
 Throttle position sensor
 Open or short in heated oxygen sensor circuit
 Heated oxygen sensor
DTC CHART (SAE Controlled)
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 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.
IN−22− INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
1996 TOYOTA T100 (RM449U)
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.