light TOYOTA T100 1996 Factory Owner's Manual

Downloaded from www.Manualslib.com manuals search engine − DIAGNOSTICSENGINE (3RZ−FE)
DI−15
1996 TOYOTA T100 (RM449U) DTC No.
(See Page)
Detection ItemTrouble AreaMIL*Memory
P0441
(DI−88)Evaporative Emission Control
System Incorrect Purge Flow
Open or short in VSV circuit for EVAP
VSV for EVAP
ECM
Vacuum hose damaged, blocked or disconnected
Charcoal canister

P0500
(DI−92)Vehicle Speed Sensor
Malfunction
Open or short in No.1 vehicle speed sensor circuit
No.1 vehicle speed sensor
ECM
Speedometer cable

P0505
(DI−94)Idle Control System
MalfunctionIAC valve is stuck or closed
Open or short in IAC valve circuit
Air intake (hose loose)

P0510
(DI−97)Closed Throttle Position
Switch MalfunctionOpen in closed throttle position switch circuit
Closed throttle position switch
ECM

*:  MIL lights up
MANUFACTURER CONTROLLED
DTC No.
(See Page)Detection ItemTrouble AreaMIL*Memory
P1300
(DI−103)Igniter Circuit Malfunction
Open or short in IGF or IGT circuit from igniter to ECM
Igniter
ECM

P1335
(DI−109)Crankshaft Position Sensor
Circuit Malfunction
(during engine running)Open or short in crankshaft position sensor circuit
Crankshaft position sensor
ECM
−
P1500
(DI−11 0)Starter Signal Malfunction
Open or short in starter signal
Open or short in ignition switch or starter relay circuit
ECM
−
P1600
(DI−11 2)ECM BATT MalfunctionOpen in back up power source circuit
ECM
P1780
(DI−11 4)Park/Neutral Position Switch
MalfunctionShort in park/neutral position switch circuit
Park/neutral position switch
ECM

*: −  MIL does not light up,  MIL lights up

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Vehicle Speed
50 ∼ 65 km/h
(31 ∼ 40 mph)
Idling
IG SW OFF
1 ∼ 3 min. 1 min. Time
(1)(2)(3)(4)
(5)
− DIAGNOSTICSENGINE (3RZ−FE)
DI−47
1996 TOYOTA T100 (RM449U)
DTC P0130 Heated Oxygen Sensor Circuit Malfunction
(Bank 1 Sensor 1)
CIRCUIT DESCRIPTION
Refer to DTC P0125 on page DI−44.
DTC No.Detection ItemDTC Detecting ConditionTrouble AreaTrouble Area
P0130
Voltage output of heated oxygen sensor remains at 0.4 V or
more or 0.55 V or less, during idling after engine is warmed
up (2 trip detection logic)Heated oxygen sensor
Fuel trim malfunction
HINT:
Sensor 1 refers to the sensor closer to the engine body.
The heated oxygen sensor’s output voltage and the short−term fuel trim value can be read using the
OBD II scan tool or TOYOTA hand−held tester.
WIRING DIAGRAM
Refer to DTC P0125 on page DI−44.
CONFIRMATION DRIVING PATTERN
(1) Connect the TOYOTA hand−held tester to the DLC3.
(2) Switch the TOYOTA hand−held tester from normal mode to check mode (See page DI−13).
(3) Start the engine and warm it up with all the accessory switches OFF.
(4) Drive the vehicle at 50 − 65 km/h (31 − 40 mph) for 1 − 3 min. to warm up the heated oxygen sensor.
(5) Let the engine idle for 1 min.
HINT:
If a malfunction exists, the MIL will light up during step (5).
NOTICE:
If the conditions in this test are not strictly followed, detection of the malfunction will not be possible.
If you do not have a TOYOTA hand−held tester, turn the ignition switch OFF after performing steps
(3) to (5), then perform steps (3) to (5) again.
DI0TK−02

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DI−55
1996 TOYOTA T100 (RM449U)
DTC P0171 System too Lean (Fuel Trim)
DTC P0172 System too Rich (Fuel Trim)
CIRCUIT DESCRIPTION
Fuel trim refers to the feedback compensation value compared against the basic injection time. Fuel trim
includes short−term fuel trim and long−term fuel trim.
Short−term fuel trim is the short−term fuel compensation used to maintain the air−fuel ratio at its ideal
theoretical value. The signal from the heated oxygen sensor indicates whether the air−fuel ratio is RICH or
LEAN compared to the ideal theoretical value, triggering a reduction in fuel volume if the air−fuel ratio is rich,
and an increase in fuel volume if it is lean.
Long−term fuel trim is overall fuel compensation carried out long−term to compensate for continual deviation
of the short−term fuel trim from the central value due to individual engine differences, wear over time and
changes in the usage environment.
If both the short−term fuel trim and long−term fuel trim are LEAN or RICH beyond a certain value, it is de-
tected as a malfunction and the MIL lights up.
DTC No.DTC Detecting ConditionTrouble Area
P0171
When air fuel ratio feedback is stable after engine warming
up, fuel trim is considerably in error on RICH side
(2 trip detection logic)
Air intake (hose loose)
Fuel line pressure
Injector blockage
Heated oxygen sensor (bank 1 sensor 1) malfunction
Mass air flow meter
Engine coolant temp. sensor
P0172
When air fuel ratio feedback is stable after engine warming
up, fuel trim is considerably in error on LEAN side
(2 trip detection logic)
Fuel line pressure
Injector leak, blockage
Heated oxygen sensor (bank 1 sensor 1) malfunction
Mass air flow meter
Engine coolant temp. sensor
HINT:
When the DTC P0171 is recorded, the actual air−fuel ratio is on the LEAN side. When DTC P0172 is
recorded, the actual air−fuel ratio is on the RICH side.
If the vehicle runs out of fuel, the air−fuel ratio is LEAN and DTC P0171 is recorded. The MIL then
comes on.
If the total of the short−term fuel trim value and long−term fuel trim value is within ± 25 %, the system
is functioning normally.
INSPECTION PROCEDURE
1 Check air induction system (See page MF−1).
NG Repair or replace.
OK
DI0TO−03

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− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
DTC P0300 Random/Multiple Cylinder Misfire Detected
DTC P0301 Cylinder 1 Misfire Detected
DTC P0302 Cylinder 2 Misfire Detected
DTC P0303 Cylinder 3 Misfire Detected
DTC P0304 Cylinder 4 Misfire Detected
CIRCUIT DESCRIPTION
Misfire: The ECM uses the crankshaft position sensor and camshaft position sensor to monitor changes in
the crankshaft rotation for each cylinder.
The ECM counts the number of times the engine speed change rate indicates that misfire has occurred. And
when the misfire rate equals or exceeds the count indicating that the engine condition has deteriorated, the
MIL lights up.
If the misfire rate is high enough and the driving conditions will cause catalyst overheating, the MIL blinks
when misfiring occurs.
DTC No.DTC Detecting ConditionTrouble Area
P0300Misfiring of random cylinders is detected during any
particular 200 or 1,000 revolutionsIgnition system
Injector
Fuel line pressure
EGR
Compression pressure
Valve clearance not to specification
Valve timing
Mass air flow meter
Engine coolant temp. sensor
P0301
P0302
P0303
P0304For any particular 200 revolutions for engine, misfiring is
detected which can cause catalyst overheating
(This causes MIL to blink)
For any particular 1,000 revolutions for engine, misfiring is
detected which causes a deterioration in emissions
(2 trip detection logic)
HINT:
When the 2 more codes for a misfiring cylinder are recorded repeatedly but no random misfire code is re-
corded, it indicates that the misfires were detected and recorded at different times.
DI0TP−03

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ECM
Throttle Body
Throttle
ValveCheck
Valve
(for A/T)
EGR Vacuum Modulator
VSVEGR
Valve
P19921
R/B No.2
IG Switch
E7 E7
(M/T)(A/T)
E01
E1 ECM
E2 EGR
THG
E6 E6
E6 E6
622
14 3
99 1
BR−B G−WP
2
2
1 9 9
EA
W−R W−R
5 V
IE1W−REA1
W−B
2
3
22 22
2
25 B−W
EFIEFI Relay
VSV for EGR
EGR Gas
Temp. Sensor B−Y
EA1
4B−Y
1C17
1A3
W−R IGN
J/B
No.1
FromFrom Battery
5
1 DI−72
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
DTC P0401 Exhaust Gas Recirculation Flow Insufficient
Detected
CIRCUIT DESCRIPTION
The EGR system recirculates exhaust gas, which is controlled to the proper quantity to suit the driving condi-
tions, into the intake air mixture to slow down combustion, reduce the combustion temp. and reduce NOx
emissions. The amount of EGR is regulated by the EGR vacuum modulator according to the engine load.
If even one of the following conditions is fulfilled, the VSV is
turned ON by a signal from the ECM.
This results in atmospheric air acting on the EGR valve, closing
the EGR valve and shutting off the exhaust gas (EGR cut−off).
Under the following conditions, EGR is cut to maintain driveabil-
ity:
Before the engine is warmed up
During deceleration (throttle valve closed)
Light engine load (amount of intake air very small)
Engine racing
DTC No.DTC Detecting ConditionTrouble Area
P0401
After engine is warmed up and run at 80 km/h (50 mph)
for 3 to 5 min., EGR gas temp. sensor value does not exceed
35°C (95°F) above ambient air temp.
(2 trip detection logic)EGR valve stuck closed
Short in VSV circuit for EGR
Open in EGR gas temp. sensor circuit
EGR hose disconnected
ECM
WIRING DIAGRAM
DI0TU−03

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(3)(5)
(4)(6)
(2)
(1)
Warm up IG SW OFFIding Vehicle Speed
70 − 90 km/h
(43 − 56 mph)
3 − 5 min.3 − 5 min. 2 min. 2 min.
Time
− DIAGNOSTICSENGINE (3RZ−FE)
DI−73
1996 TOYOTA T100 (RM449U)
SYSTEM CHECK DRIVING PATTERN
(1) Connect the OBD II scan tool or TOYOTA hand−held tester to the DLC3.
(2) Start and warm up the engine with all the accessories switched OFF.
(3) Run the vehicle at 70 − 90 km/h (43 − 56 mph) for 3 min. or more.
(4) Idle the engine for about 2 min.
(5) Do steps (3) and (4) again.
(6) Check the ”READINESS TESTS” mode on the OBD II scan tool or TOYOTA hand−held tester.
If ”COMPL” is displayed and the MIL does not light up, the system is normal.
If ”INCMPL” is displayed and the MIL does not light up, run the vehicle step (5) from somes times and check
it.
HINT:
”INCMPL” is displayed when either condition (a) or (b) exists.
(a) The system check is incomplete.
(b) There is a malfunction in the system.
If there is a malfunction in the system, the MIL will light up after steps (2) to (5) above are done.

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OX Signal Waveform (Oscilloscope)
1.0 V
0 V
200 msec. /Division
− DIAGNOSTICSENGINE (3RZ−FE)
DI−87
1996 TOYOTA T100 (RM449U)
(1) Connect the OBD ll scan tool or TOYOTA hand−held tester to the DLC3.
(2) Start engine and warm it up with all accessories switched OFF until the water temperature is stable.
(3) Race the engine at 2500 − 3000 rpm for about 3 min.
(4) After confirming that the waveform of the heated oxygen sensor, bank 1 sensor 1 (OX1), oscillate around
0.5 V during feedback to the ECM, check the waveform of the heated oxygen sensor bank 1 sensor 2 (OX2).
HINT:
If there is a malfunction in the system, the waveform of the
heated oxygen sensor bank 1 sensor 2 (OX2) is almost the
same as that of the heated oxygen sensor bank 1 sensor 1
(OX1) on the left.
There are some cases where, even though a malfunction
exists, the MIL may either light up or not light up.
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P0420) being output?
YES Go to relevant DTC chart.
NO
2 Check heated oxygen sensor (bank 1 sensor 1) (See page DI−47).
NG Repair or replace.
OK
3 Check heated oxygen sensor (bank 1 sensor 2) (See page DI−53).
NG Repair or replace.
OK
Replace TWC (three−way catalytic convert-
er) (See page EM−104).

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ENGINE CONTROL SYSTEM Check Sheet
Customer’s Name
Driver’s Name
Date 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
Driveability
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
Dates Problem
Occurred
Problem Frequency
Condition When
Problem Occurs
Weather
Engine Operation
Engine Temp. Place Outdoor Temp.Constant
Sometimes ( times per day/month)Once only
Other
Fine
CloudyRainySnowyVarious/Other
Hot
Warm CoolCold (approx. °F/ °C)
Highway
SuburbsInner cityUphillDownhill
Rough road
Other
Cold
Warming upAfter warming upAny temp.Other
Starting
Just after starting ( min.)IdlingRacing
Driving
Constant speedAccelerationDeceleration
A/C switch ON/OFF
Other
Condition of MILRemains on Sometimes lights up Does not light up
NormalMalfunction code(s) (code )
Freezed frame data ( )
NormalMalfunction code(s) (code )
Freezed frame data ( )
Normal Mode
(Precheck)
Check Mode DTC InspectionInspector’s
Name
DI−128
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
CUSTOMER PROBLEM ANALYSIS CHECK

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DI0UB−02
FI7231
TOYOTA Hand−Held Tester
DLC 3
− DIAGNOSTICSENGINE (5VZ−FE)
DI−129
1996 TOYOTA T100 (RM449U)
PRE−CHECK
1. DIAGNOSIS SYSTEM
(a) Description
When troubleshooting OBD II vehicles, the only dif-
ference from the usual troubleshooting procedure
is that you connect to the vehicle the OBD II scan
tool complying with SAE J1978 or TOYOTA hand−
held tester, and read off various data output from
the vehicle’s ECM.
OBD II regulations require that the vehicle’s on−
board computer lights up the Malfunction Indicator
Lamp (MIL) on the instrument panel when the com-
puter detects a malfunction in the computer itself or
in drive system components which affect vehicle
emissions. In addition to the MIL lighting up when
a malfunction is detected, the applicable Diagnostic
Trouble Codes (DTCs) prescribed by SAE J2012
are recorded in the ECM memory (See page
DI−140).
If the malfunction does not reoccur in 3 trips, the MIL goes off
but the DTCs remain recorded in the ECM memory.
To check the DTCs, connect the OBD II scan tool or
TOYOTA hand−held tester to the Data Link Con-
nector 3 (DLC3) on the vehicle. The OBD II scan
tool or TOYOTA hand−held tester also enables you
to erase the DTCs and check freezed frame data
and various forms of engine data (For operating
instructions, see the OBD II scan tool’s instruction
book.).
DTCs include SAE controlled codes and manufac-
turer controlled codes. SAE controlled codes must
be set as prescribed by the SAE, while manufactur-
er controlled codes can be set freely by the
manufacturer within the prescribed limits (See DTC
chart on page DI−140).

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DLC3 DI−130
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
The diagnosis system operates in normal mode
during normal vehicle use. It also has a check mode
for technicians to simulate malfunction symptoms
and troubleshoot. Most DTCs use 2 trip detection
logic* to prevent erroneous detection, and ensure
thorough malfunction detection. By switching the
ECM to check mode when troubleshooting, the
technician can cause the MIL to light up for a mal-
function that is only detected once or momentarily
(TOYOTA hand−held tester only).
*2 trip detection logic: When a logic malfunction is
first detected, the malfunction is temporarily stored
in the ECM memory. If the same malfunction is de-
tected again during the 2nd drive test, this 2nd
detection causes the MIL to light up.
The 2 trip repeats the same mode a 2nd time. (How-
ever, the ignition switch must be turned OFF be-
tween the 1st trip and 2nd trip.)
Freeze frame data:
Freeze frame data records the engine condition
when a misfire (DTCs P0300 − P0306) or fuel trim
malfunction (DTCs P0171, P0172) or other mal-
function (first malfunction only), is detected.
Because freeze frame data records the engine
conditions (fuel system, calculator load, engine
coolant temperature, fuel trim, engine speed, ve-
hicle speed, etc.) when the malfunction is detected,
when troubleshooting it is useful for determining
whether the vehicle was running or stopped, the en-
gine warmed up or not, the air−fuel ratio lean or rich,
etc. at the time of the malfunction.
Priorities for troubleshooting:
If troubleshooting priorities for multiple DTCs are given in the
applicable DTC chart, these should be followed.
If no instructions are given troubleshoot DTCs according to the
following priorities.
(1) DTCs other than fuel trim malfunction (DTCs
P0171, P0172), EGR (DTCs P0401, P0402) and
misfire (DTCs P0300 − P0306).
(2) Fuel trim malfunction (DTCs P0171, P0172) and
EGR (DTCs P0401, P0402).
(3) Misfire (DTCs P0300 − P0306).
(b) Check the DLC3
The vehicle’s ECM uses V.P.W. (Variable Pulse Width) for
communication to comply with SAE J1850. The terminal
arrangement of DLC3 complies with SAE J1962 and
matches the V.P.W. format.