TOYOTA T100 1996 Factory Service Manual

Downloaded from www.Manualslib.com manuals search engine − DIAGNOSTICSENGINE (5VZ−FE)
DI−187
1996 TOYOTA T100 (RM449U)
5 Check injector injection (See page SF−21).
NG Replace injector.
OK
6 Check EGR system (See page EC−9).*
NG Repair EGR system.*
OK
*: Only for 2WD models with a load capacity of 0.5 ton and regular cab.
7 Check mass air flow meter and engine coolant temp. sensor (See page SF−29
and SF−52).
NG Repair or replace.
OK
Check the compression pressure (See page EM−2), valve clearance (See page EM−4) and valve
timing (See page EM−17).

Downloaded from www.Manualslib.com manuals search engine P19919
ECM
KNK1
KNK2E1
E1 617
316 E6
E6E6
E6
(M/T)(A/T) BB
GRGR EC1
EC11
2 1
1 Knock Sensor 1
(On right bank)
Knock Sensor 2
(On left bank) DI−188
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
DTC P0325 Knock Sensor 1 Circuit Malfunction
DTC P0330 Knock Sensor 2 Circuit Malfunction
CIRCUIT DESCRIPTION
Knock sensors are fitted one to the right bank and left bank of 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 vibrates 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 between
1,760 rpm and 5,600 rpmOpen or short in knock sensor 1 circuit
Knock sensor 1 (looseness)
ECM
P0330No knock sensor 2 signal to ECM with engine speed between
1,760 rpm and 5,600 rpmOpen or short in knock sensor 2 circuit
Knock sensor 2 (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
DI0UU−01

Downloaded from www.Manualslib.com manuals search engine A00053
A00054 P20457
A00112
ECM
Knock Sensor
Female
ConnectorMale
Connector 11
2
2
E6 E6
E6
E6KNK1
KNK2 17 6
3161
1
(M/T)(A/T)
EC1
EC1
− DIAGNOSTICSENGINE (5VZ−FE)
DI−189
1996 TOYOTA T100 (RM449U)
INSPECTION PROCEDURE
HINT:
DTC P0325 is for the right bank knock sensor circuit. DTC P0330 is for the left bank knock sensor circuit.
1 Connect OBD II scan tool or TOYOTA hand−held tester and check knock sensor
circuit.
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand−held tes-
ter to the DLC3.
(b) Disconnect the wire to wire connector EC1.
(c) Connect the terminals of the disconnected EC1 male con-
nector and EC1 female as follows.
Male connector ↔Female connector
Terminal 1 ↔ Terminal 2
Terminal 2 ↔ Terminal 1
(d) Turn the ignition switch ON and push the OBDII scan tool
or TOYOTA hand−held tester main switch ON.
(e) After the engine is warmed up, perform quick racing to
4,000 rpm 3 times.
CHECK:
Check the DTC.
RESULT:
Type IDTC same as when vehicle brought in
P0325 → P0325 or P0330 → P0330
Type IIDTC different to when vehicle brought in
P0325 → P0330 or P0330 → P0325
Type II Go to step 3.
Type I
2 Check for open and short in harness and connector between EC1 connector and
ECM (See page IN−26).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page
IN−26).

Downloaded from www.Manualslib.com manuals search engine FI6510FI6607A00113
KNK signal waveform
0.5 V
/Division
5 msec./Division
100 μsec./Division 0V
200 mV
/Division
0V DI−190
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
3 Check for open and short in harness and connector between EC1 connector and
knock sensor (See page IN−26).
HINT:
If DTC P0325 has changed to P0330, check the knock sensor circuit on the right bank side.
If DTC P0330 has changed to P0325, check the knock sensor circuit on the left bank side.
NG Repair or replace harness or connector.
OK
Replace knock sensor.
Reference INSPECTION USING OSCILLOSCOPE
With the engine racing (4,000 rpm), measure between
terminal KNK1, KNK2 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 141 μsec (Normal mode vibration
frequency of knock sensor: 7.1 kHz).
HINT:
If normal mode vibration frequency is not 7.1 kHz, the sensor
is malfunctioning.

Downloaded from www.Manualslib.com manuals search engine P25501
ECM
G
G−
NE
NE− B
W
G
L 1
2
1
2 Camshaft Position Sensor
Crankshaft Position Sensor11 1 0
511
12 5
66 E5 E5
E5
E5E6
E6
E6
E6
E1
(M/T) (A/T)
− DIAGNOSTICSENGINE (5VZ−FE)
DI−191
1996 TOYOTA T100 (RM449U)
DTC P0335 Crankshaft Position Sensor ”A” Circuit
Malfunction
CIRCUIT DESCRIPTION
The crankshaft position sensor, which detects the engine speed and crankshaft angle signal (NE signal),
has been installed on the oil pump body.
The NE signal plate has 34 teeth. 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
and 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
DI0UV−01

Downloaded from www.Manualslib.com manuals search engine FI7059
FI7060
A00069
G, NE signal waveform
G
G NE
NE5 V
/Division
5 V
/Division 20 msec./Division (Idling)
10 msec./Division (Idling)
DI−192
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
INSPECTION PROCEDURE
1 Check resistance of crankshaft position sensor (See page IG−13).
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 − DIAGNOSTICSENGINE (5VZ−FE)
DI−193
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 DI−194
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
DTC P0340 Camshaft Position Sensor Circuit
Malfunction
CIRCUIT DESCRIPTION
The camshaft position sensor which detects the crankshaft angle signal (G signal), has been installed on
the front of right bank cylinder head. The timing rotor has been integrated with the right bank camshaft timing
pulley. When the camshafts rotate, the protrusion on the timing rotor 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
Starter
ECM
No camshaft position sensor signal to ECM with engine
speed 600 rpm or more
WIRING DIAGRAM
Refer to DTC P0335 on page DI−191.
INSPECTION PROCEDURE
1 Check resistance of camshaft position sensor (See page IG−1).
Reference INSPECTION USING OSCILLOSCOPE
Refer to DTC P0335 on page DI−191.
NG Replace camshaft position sensor.
OK
2 Check for open and short in harness and connector between ECM and camshaft
position sensor (See page IN−26).
NG Repair or replace harness or connector.
OK
DI0UW−02

Downloaded from www.Manualslib.com manuals search engine − DIAGNOSTICSENGINE (5VZ−FE)
DI−195
1996 TOYOTA T100 (RM449U)
3 Inspect sensor installation.
NG Tighten the sensor.
OK
Check and replace ECM (See page IN−26).

Downloaded from www.Manualslib.com manuals search engine FI4825
EGR
Vacuum
Modulator ECM
VSV EGR Valve Throttle Body
Throttle
Valve
Intake Air
Chamber
Exhaust Gas
P19921
R/B No.2 IG Switch
E4 E5
(M/T)(A/T)
E01
E1 ECM
E2 EGR
THG
E6 E6
E6 E6
18 8
21 14
922 1
BR−B P2
2
1 9 9
EA
W−R W−R
IE1W−REA1
W−B
2 3
2
2 2
2 2
2
2
1 1
5 B−W
EFIEFI Relay
VSV for EGR
EGR Gas
Temp. SensorB−YEA14B−Y
1C17
1A3
W−R IGNJ/B
No.1FromFrom Battery
R−W
5 V DI−196
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
DTC P0401 Exhaust Gas Recirculation Flow Insufficient
Detected*
*: Only for 2WD models with a load capacity of 0.5 ton and regular cab.
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
driveability:
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 valve does not
exceed 60°C (140°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
DI0UX−01