1996 TOYOTA T100 display

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.

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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.

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.

Downloaded from www.Manualslib.com manuals search engine − INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN−23
1996 TOYOTA T100 (RM449U)
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.
Symptom
Suspect AreaSee page
Engine does not crank (Does not start)
No initial combustion (Does not start)
No complete combustion (Does not start)1. Starter and starter relay
1. ECM power source circuit
2. Fuel pump control circuit
3. Engine control module (ECM)
1. Starter signal circuit
2. Fuel pump control circuit1. Fuel pump control circuitST − 2, ST − 17
DI − 101
DI − 104
IN − 28
PROBLEM SYMPTOMS TABLE
1. Compression
2. Fuel pump control circuit 1. A/C signal circuit
2. Fuel pump control circuit 1. A/C signal circuit (Compressor circuit)
2. ECM power source circuit 1. Starter signal circuit
2. Fuel pump control circuit1. Starter signal circuit
2. Fuel pump control circuit
3. Compression
idling) High engine idle speed (Poor idling) Hot engine Cold engine (Difficult to start)Engine cranks normally (Difficult to start)
DI − 101 DI − 173
DI − 104 DI − 173
DI − 104 DI − 104
DI − 173
DI − 104
 Problem Symptom Page
Indicates the page where the flow chart for each circuit
is located.
 Circuit Inspection, Inspection Order
Indicates the circuit which needs to be checked for each problem
symptom. Check in the order indicated by the numbers.
 Circuit or Part Name
Indicates the circuit or part which needs to be checked.
AC − 85 EM − 3

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Vehicle Brought to Workshop
Customer Problem Analysis P. DI−2
Problem Symptom Confirmation
If the engine does not start perform steps 10 and 12 firstConnect the OBD II scan tool or TOYOTA hand−held tester to DLC3 P. DI−3
If the display indicates a communication fault in the tool, inspect DLC3 P. DI−3
Check DTC and Freezed Frame Data (Precheck)
Record or Print DTC and Freezed Frame Data P. DI−3
Clear DTC and Freezed Frame Data P. DI−3
Visual Inspection
Setting the Check Mode Diagnosis P. DI−3
Symptom Simulation P.IN−16
Basic Inspection P. DI−3DTC Chart P. DI−13
Problem Symptoms Table P. DI−21
Circuit Inspection P. DI−22
Adjustment, Repair
DTC Check P. DI−3
Titles insideare titles of pages in
in the bottom portion. See the indicated
pages for detailed explanations.this manual with the page number indicated
Malfunction
occurs.Malfunction does not occur.
Parts Inspection
Check for Intermittent Problems P. DI−3
Identification of Problem
Confirmation Test
End 1
2
3
4
5
6
7
108
9
11
12
13
15 14
16
Normal Malfunction code.
17
− DIAGNOSTICSENGINE (3RZ−FE)
DI−1
258 Author: Date:
1996 TOYOTA T100 (RM449U)
ENGINE (3RZ−FE)
HOW TO PROCEED WITH TROUBLESHOOTING
Troubleshoot in accordance with the procedure on the following page.

Downloaded from www.Manualslib.com manuals search engine A00653
w/o Tachometer
w/ Tachometer
− DIAGNOSTICSENGINE (3RZ−FE)
DI−5
1996 TOYOTA T100 (RM449U)
HINT:
If your display shows ”UNABLE TO CONNECT TO VEHICLE”
when you have connected the cable of the OBD II scan tool or
TOYOTA hand−held tester to DLC3, turned the ignition switch
ON and operated the scan tool, there is a problem on the ve-
hicle side or tool side.
If communication is normal when the tool is connected to
another vehicle, inspect DLC3 on the original vehicle.
If communication is still not possible when the tool is con-
nected to another vehicle, the problem is probably in the
tool itself, so consult the Service Department listed in the
tool’s instruction manual.
2. INSPECT DIAGNOSIS (Normal Mode)
(a) Check the MIL.
(1) The MIL comes on when the ignition switch is turned
ON and the engine is not running.
HINT:
If the MIL does not light up, troubleshoot the combination meter.
(2) When the engine started, the MIL should go off. If
the lamp remains on, the diagnosis system has de-
tected a malfunction or abnormality in the system.
(b) Check the DTC.
NOTICE:
TOYOTA hand−held tester only: When the diagnosis sys-
tem is switched from normal mode to check mode, it
erases all DTCs and freezed frame data recorded in normal
mode. So before switching modes, always check the DTCs
and freezed frame data, and note them down.
(1) Prepare the OBD II scan tool (complying with SAE
J1978) or TOYOTA hand−held tester.
(2) Connect the OBD II scan tool or TOYOTA hand−
held tester to the DLC3 at the lower of the instru-
ment panel.
(3) Turn the ignition switch ON and turn the OBD II scan
tool or TOYOTA hand−held tester switch ON.
(4) Use the OBD II scan tool or TOYOTA hand−held
tester to check the DTCs and freezed frame data,
note them down. (For operating instructions, see
the OBD II scan tool’s instruction book.)
(5) See page DI−13 to confirm the details of the
DTCs.

Downloaded from www.Manualslib.com manuals search engine − DIAGNOSTICSENGINE (3RZ−FE)
DI−11
1996 TOYOTA T100 (RM449U)
7. ENGINE OPERATING CONDITION
NOTICE:
The values given below for ”Normal Condition” are representative values, so a vehicle may still be
normal even if its value varies from those listed here. So do not decide whether a part is faulty or not
solely according to the ”Normal Condition” here.
(a) CARB mandated signals.
TOYOTA hand−held tester displayMeasurement ItemNormal Condition*
FUEL SYS #1
Fuel System Bank 1
OPEN: Air−fuel ratio feedback stopped
CLOSED: Air−fuel ratio feedback operating
Idling after warming up: CLOSED
CALC LOAD
Calculator Load:
Current intake air volume as a proportion of max.
intake air volumeIdling: 15.4 − 22.1 %
Racing without load (2,500 rpm): 14.7 − 21.5 %
COOLANT TEMP.Engine Coolant Temp. Sensor ValueAfter warming up: 80 ∼ 95°C (176 ∼ 203°F)
SHORT FT #1Short−term Fuel Trim Bank 10 ± 20 %
LONG FT #1Long−term Fuel Trim Bank 10 ± 20 %
ENGINE SPDEngine SpeedIdling: 650 − 750 rpm
VEHICLE SPDVehicle SpeedVehicle Stopped: 0 km/h (0 mph)
IGN ADVANCEIgnition Advance:
Ignition Timing of Cylinder No.1Idling: BTDC 7 − 13°
INTAKE AIRIntake Air Temp. Sensor ValueEquivalent to Ambient Temp.
MAFAir Flow Rate Through Mass Air Flow Meter
Idling: 2.7 − 3.9 gm/sec.
Racing without load (2,500 rpm):
9.2 − 13.3 gm/sec.
THROTTLE POS
Voltage Output of Throttle Position Sensor
Calculated as a percentage:
0 V →0 %, 5 V →100 %Throttle Fully Closed: 7 − 11 %
Throttle Fully Open: 65 − 75 %
O2S B1, S1Voltage Output of Oxygen Sensor
Bank 1, Sensor 1Idling: 0.1 − 0.9 V
O2FT B1, S1Oxygen Sensor Fuel Trim Bank 1, Sensor 1
(Same as SHORT FT #1)0 ± 20 %
O2S B1, S2Voltage Output of Oxygen Sensor
Bank 1, Sensor 2Driving (50 km/h, 31 mph): 0.1 − 0.9 V
*: If no conditions are specifically stated for ”ldling”, it means the shift lever is at N or P position, the A/C switch
is OFF and all accessory switches are OFF.

Downloaded from www.Manualslib.com manuals search engine DI−12
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
(b) TOYOTA Enhanced Signals.
TOYOTA hand−held tester displayMeasurement ItemNormal Condition*
MISFIRE RPMEngine RPM for first misfire rangeMisfire 0: 0 rpm
MISFIRE LOADEngine load for first misfire rangeMisfire 0: 0 g/r
INJECTORFuel injection time for cylinder No.1Idling: 2.5 − 4.3 ms
IAC DUTY RATIOIntake Air Control Valve Duty Ratio
Opening ratio rotary solenoid type IAC valveIdling: 24.8 − 50.0 %
STARTER SIGStarter SignalCranking: ON
CTP SWClosed Throttle Position Switch SignalThrottle Fully Closed: ON
A/C SIGA/C Switch SignalA/C ON: ON
STOP LIGHT SWStop Light Switch SignalStop light switch ON: ON
FC IDLFuel Cut Idle: Fuel cut when throttle valve fully
closed, during decelerationFuel cut operating: ON
FC TAUFuel Cut TAU: Fuel cut during very light loadFuel cut operating: ON
CYL #1, CYL #2, CYL #3, CYL #4Abnormal revolution variation for each cylinder0 %
IGNITIONTotal number of ignition for every 1,000
revolutions0 − 2,000
EGRT GASEGR Gas Temp. Sensor ValueEGR not operating: Temp. between intake air
temp. and engine coolant temp.
EGR SYSTEMEGR System Operating ConditionIdling: OFF
A/C CUT SIGA/C Cut SignalA/C S/W OFF: ON
FUEL PUMPFuel Pump SignalIdling: ON
EVAP (PURGE) VSVEVAP VSV SignalIdling: OFF
TOTAL FT B1Total Fuel Trim Bank 1: Average value for fuel
trim system of bank 1Idling: 0.8 − 1.2 V
O2 LR B1, S1
Oxygen Sensor Lean Rich Bank 1, Sensor 1 Re-
sponse time for oxygen sensor output to switch
from lean to rich
Idling after warming up: 0 − 1,000 msec.
O2 RL B1, S1
Oxygen Sensor Rich Lean Bank 1, Sensor 1 Re-
sponse time for oxygen sensor output to switch
from rich to lean
Idling after warming up: 0 − 1,000 msec.
*: If no conditions are specifically stated for ”ldling”, it means the shift lever is at N or P position, the A/C switch
is OFF and all accessory switches are OFF.