1996 TOYOTA T100 engine

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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

Downloaded from www.Manualslib.com manuals search engine FI7059
FI7060
A00069
G, NE signal waveform
5 V/
Division
5 V/
Division G
NE
G
NE20 msec./Division (Idling)
10 msec./Division (Idling)
− DIAGNOSTICSENGINE (3RZ−FE)
DI−67
1996 TOYOTA T100 (RM449U)
INSPECTION PROCEDURE
1 Check resistance of crankshaft position sensor (See page IG−14).
Reference: INSPECTION USING OSCILLOSCOPE
During cranking or idling, check between terminals G and G−,
NE and NE− of ECM
HINT:
The correct waveforms are as shown.
NG Replace crankshaft position sensor.
OK
2 Check for open and short in harness and connector between ECM and crank-
shaft position sensor (See page IN−26).
NG Repair or replace harness or connector.
OK

Downloaded from www.Manualslib.com manuals search engine DI−68
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
3 Inspect sensor installation and teeth of signal plate.
NG Tighten the sensor. Replace signal plate.
OK
Check and replace ECM (See page IN−26).

Downloaded from www.Manualslib.com manuals search engine − DIAGNOSTICSENGINE (3RZ−FE)
DI−69
1996 TOYOTA T100 (RM449U)
DTC P0336 Crankshaft Position Sensor ”A” Circuit
Range/Performance
CIRCUIT DESCRIPTION
Refer to DTC P0335 on page DI−66.
If the ECM records the DTC P0336, it operates the fail safe function, stopping the fuel injection.
DTC No.DTC Detecting ConditionTrouble Area
P0336Deviation on crankshaft position sensor signal and camshaft
position sensor signalValve timing
Distributor installation
ECM
INSPECTION PROCEDURE
1 Check valve timing (See page EM−38).
NG Adjust valve timing.
OK
2 Check distributor installation (See page EM−5).
NG Reinstall distributor.
OK
Check and replace ECM (See page IN−26).
DI0TS−02

Downloaded from www.Manualslib.com manuals search engine DI−70
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
DTC P0340 Camshaft Position Sensor Circuit
Malfunction
CIRCUIT DESCRIPTION
Camshaft position sensor (G signal) consist of signal plate and pickup coil. The G signal plate has one tooth
on its outer circumference and is built into the distributor.
When the camshafts rotate, the protrusion on the signal plate and the air gap on the pickup coil change,
causing fluctuations in the magnetic field and generating an electromotive force in the pickup coil.
The NE signal plate has 34 teeth and is mounted on the crankshaft. The NE signal sensor generates 34
signals for every engine revolution. The ECM detects the standard crankshaft angle based on the G signals
and the actual crankshaft angle and the engine speed by the NE signals.
DTC No.DTC Detecting ConditionTrouble Area
P0340
No camshaft position sensor signal to ECM during cranking
(2 trip detection logic)Open or short in camshaft position sensor circuit
Camshaft position sensor
Distributor
Starter
ECM
No camshaft position sensor signal to ECM during engine run-
ning
WIRING DIAGRAM
Refer to DTC P0335 on page DI−66.
INSPECTION PROCEDURE
1 Check resistance of camshaft position sensor (See page EM−3).
Reference: INSPECTION USING OSCILLOSCOPE
Refer to DTC P0335 on page DI−66.
NG Replace distributor housing.
OK
2 Check for open and short in harness and connector between ECM and
distributor (See page IN−26).
NG Repair or replace harness or connector.
OK
DI0TT−03

Downloaded from www.Manualslib.com manuals search engine − DIAGNOSTICSENGINE (3RZ−FE)
DI−71
1996 TOYOTA T100 (RM449U)
3 Check air gap (See page EM−1).
NG Replace distributor housing.
OK
Check and replace ECM (See page IN−26).

Downloaded from www.Manualslib.com manuals search engine P19893
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