TOYOTA T100 1996 Factory Service Manual

Downloaded from www.Manualslib.com manuals search engine − DIAGNOSTICSENGINE (3RZ−FE)
DI−57
1996 TOYOTA T100 (RM449U)
5 Check mass air flow meter and engine coolant temp. sensor (See page
DI−22,DI−33).
NG Repair or replace.
OK
6 Check for spark and ignition (See page IG−1).
NG Repair or replace.
OK
Check and replace ECM (See page IN−26).

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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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W−RW−R
IA3
R/B No.2
Battery
R−L
W
Ignition
Switch
AM2
2
28
8
7
B−R
IE114
B−R
B−R
B−R
B−R
B−R
EB
2
2
2
2Injector
No.1
No.3
No.2
No.4
W−R
W
W−R
W−R
W
W
BR
BR 1
1
1
112 12
11 11 E7 E7
E7 E7
E7 E7
E7 E7 13 13
26 26
(M/T)(A/T)
#10
#20
E01
E02
ECM
FI6588
FI6538
A00064
10 V/
Division
GND10 V/
Division
100 msec./Division (Idling)GND(Magnification)
1 msec./Division (Idling)
Injection duration
− DIAGNOSTICSENGINE (3RZ−FE)
DI−59
1996 TOYOTA T100 (RM449U)
WIRING DIAGRAM
Reference: INSPECTION USING OSCILLOSCOPE
INJECTOR SIGNAL WAVEFORM
With the engine idling, measure between terminals #10, #20 and E01 of ECM.
HINT:
The correct waveform is as shown.

Downloaded from www.Manualslib.com manuals search engine P03792
P25086
A00065
DI−60
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
INSPECTION PROCEDURE
1 Check spark plug and spark of misfiring cylinder.
PREPARATION:
(a) Disconnect the high−tension cord.
(b) Remove the spark plug.
CHECK:
(a) Check the carbon deposits electrode.
(b) Check the electrode gap.
OK:
(1) No large carbon deposit present. Not wet with gas-
oline or oil.
(2) Electrode gap: 0.8 mm (0.031 in.)
PREPARATION:
(a) Install the spark plug to the high−tension code.
(b) Disconnect the injector connector.
(c) Ground the spark plug.
CHECK:
Check if the spark occurs while the engine is being craked.
NOTICE:
To prevent excess fuel being injected from the injectors
during this test, don’t crank the engine for more than 5 − 10
seconds at a time.
OK:
Spark jumps across electrode gap.
NG Replace or check ignition system (See page
IG−1).
OK

Downloaded from www.Manualslib.com manuals search engine BE6653
P23816
P23817
A00066
For M/T
#10 (+) #20 (+)
#10 (+) #20 (+)
For A/T
− DIAGNOSTICSENGINE (3RZ−FE)
DI−61
1996 TOYOTA T100 (RM449U)
2 Check voltage of ECM terminal for injector of failed cylinder.
PREPARATION:
(a) Remove the right cowl side trim (See page MF−50).
(b) Turn the ignition switch ON.
CHECK:
Measure voltage between applicable terminal of ECM connec-
tor and body ground.
OK:
Voltage: 9 − 14 V
OK Go to step 4.
NG
3 Check resistance of injector of misfiring cylinder (See page MF−16).
NG Replace injector.
OK
Check for open and short in harness and con-
nector between injector and ECM (See page
IN−26).
4 Check fuel pressure (See page MF−5).
NG Check and repair fuel pump, pressure regulator,
fuel pipe line and filter (See page MF−10).
OK

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− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
5 Check injector injection (See page MF−16).
NG Replace injector.
OK
6 Check EGR system (See page EC−7).
NG Repair EGR system.
OK
7 Check mass air flow meter and engine coolant temp. sensor (See page DI−22,
DI−33).
NG Repair or replace.
OK
Check compression pressure, valve clear-
ance and valve timing.

Downloaded from www.Manualslib.com manuals search engine P19613
Knock Sensor 1
(M/T) (A/T)13 6
E6 E6
E1 KNKECM
B 1
− DIAGNOSTICSENGINE (3RZ−FE)
DI−63
1996 TOYOTA T100 (RM449U)
DTC P0325 Knock Sensor 1 Circuit Malfunction
CIRCUIT DESCRIPTION
Knock sensor is fitted to the cylinder block to detect engine knocking. This sensor contains a piezoelectric
element which generates a voltage when it becomes deformed, which occurs when the cylinder block vi-
brates due to knocking. If engine knocking occurs, ignition timing is retarded to suppress it.
DTC No.DTC Detecting ConditionTrouble Area
P0325No knock sensor 1 signal to ECM with engine speed 1,200 rpm
or moreOpen or short in knock sensor 1 circuit
Knock sensor 1 (looseness)
ECM
If the ECM detects the above diagnosis conditions, it operates the fail safe function in which the corrective
retard angle value is set to the maximum value.
WIRING DIAGRAM
DI0TQ−03

Downloaded from www.Manualslib.com manuals search engine AB0117
P23818
P24201
A00067
LOCK
For M/T
For A/TKNK
KNK
E6 Connector
E6 Connector
DI−64
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
INSPECTION PROCEDURE
1 Check continuity between terminal KNK of ECM connector and body ground.
PREPARATION:
(a) Remove the right cowl side trim (See page MF−51).
(b) Disconnect the E6 connector of ECM.
CHECK:
Measure resistance between terminal KNK of ECM connector
and body ground.
OK:
Resistance: 1 MΩ or higher
OK Go to step 3.
NG
2 Check knock sensor (See page MF−47).
NG Replace knock sensor.
OK
3 Check for open and short in harness and connector between ECM and knock
sensor (See page IN−26).
NG Repair or replace harness or connector.
OK

Downloaded from www.Manualslib.com manuals search engine A00068
KNK signal waveform
0.5 V/
Division
0.5 V/
Division0 V
0 V5 msec./Division
100 μsec./Division
− DIAGNOSTICSENGINE (3RZ−FE)
DI−65
1996 TOYOTA T100 (RM449U)
4 Does malfunction disappear when a good knock sensor is installed?
YES Replace knock sensor.
NO
Check and replace ECM (See page IN−26).
Reference: INSPECTION USING OSCILLOSCOPE
With the engine racing (4,000 rpm), measure between
terminal KNK of ECM and body ground.
HINT:
The correct waveform is as shown.
Spread the time on the horizontal axis, and confirm that
period of the wave is 151 μsec (Normal mode vibration
frequency of knock sensor: 6.6 kHz).
HINT:
If normal mode vibration frequency is not 6.6 kHz the sensor is
malfunctioning.

Downloaded from www.Manualslib.com manuals search engine A00059
ECM
411
3
1
2R
G
W
B5
18
12
175
4
6 E7
E7
E7
E7E5
E5
E5
E5G
NE− NE G−
E1 (M/T)(A/T) Camshaft Position Sensor
(Built into distributor)
Crankshaft Position Sensor DI−66
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
DTC P0335 Crankshaft Position Sensor ”A” Circuit
Malfunction
CIRCUIT DESCRIPTION
Crankshaft position sensor (NE signal) consist of a signal plate and pickup coil.
The NE signal plate has 34 teeth and is mounted on the crankshaft. The NE signal sensor generates 34
signals of every engine revolution. The ECM detects the standard crankshaft angle based on the G signals,
and the actual crankshaft angle the engine speed by the NE signals.
DTC No.DTC Detecting ConditionTrouble Area
P0335
No crankshaft position sensor signal to ECM during cranking
(2 trip detection logic)Open or short in crankshaft position sensor circuit
Crankshaft position sensor
Starter
ECM
No crankshaft position sensor signal to ECM with engine
speed 600 rpm or more (2 trip detection logic)
WIRING DIAGRAM
DI0TR−03