engine TOYOTA T100 1996 Factory Service Manual

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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

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− 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

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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).

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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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P19555
A00046
EGR Gas Temp.
SensorECM
14 3
99 2
1
E6
E6THG
E25 V
E1 E6
E6
(M/T)(A/T)
ON
DI−74
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
INSPECTION PROCEDURE
TOYOTA hand−held tester:
1 Connect TOYOTA hand−held tester and read value of EGR gas temp. value.
PREPARATION:
(a) Connect the TOYOTA hand−held tester to the DLC3.
(b) Turn the ignition switch ON and push the TOYOTA hand−held tester main switch ON.
CHECK:
Read EGR gas temp. on the TOYOTA hand−held tester.
OK:
EGR gas temp.: 10°C (50°F) or more
HINT:
If there is an open circuit, the TOYOTA hand−held tester indicates 3.1°C (37.6°F).
OK Go to step 4.
NG
2 Check for open in harness or ECM.
PREPARATION:
(a) Disconnect the EGR gas temp. sensor connector.
(b) Connect the sensor wire harness terminals together.
(c) Turn the ignition switch ON.
CHECK:
Read EGR gas temp. on the TOYOTA hand−held tester.
OK:
EGR gas temp.: 159.3°C (318.7°F)
OK Confirm good connection at sensor.
If OK, replace EGR gas temp. sensor.
NG

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P19553
P19705
P19681
A00070
EGR Gas Temp.
SensorECM
14 3
99 2
1
THG
E25 V
E1 E6
(M/T)(A/T)E6E6
E6
ON
THGE2
THGE2 For M/T
For A/T
− DIAGNOSTICSENGINE (3RZ−FE)
DI−75
1996 TOYOTA T100 (RM449U)
3 Check for open in harness or ECM.
PREPARATION:
(a) Remove the right cowl side trim (See page MF−50).
(b) Connect between terminals THG and E2 of the ECM con-
nector.
HINT:
The EGR gas temp. sensor connector is disconnected. Before
checking, do a visual check and contact pressure check for the
ECM connector (See page IN−26).
CHECK:
Read EGR gas temp. on the TOYOTA hand−held tester.
OK:
EGR gas temp.: 159.3°C (318.7°F)
OK Open in harness between terminals E2 or THG.
Repair or replace harness.
NG
Confirm connection at ECM.
If OK, replace ECM.
4 Check connection of vacuum hose and EGR hose (See page EC−2).
NG Repair or replace.
OK

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FI7205 FI7206
A00071
ON
System is OFF System is ON
Air
F EF EAir
DI−76
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
5 Check VSV for EGR.
PREPARATION:
Select the ”ACTIVE TEST” mode on the TOYOTA hand−held
tester.
CHECK:
Check operation of VSV when it is operated by the TOYOTA
hand−held tester.
OK:
EGR system is OFF:
Air flows from port E to port F.
EGR system is ON:
Air does not flow from port E to port F.
OK Go to step 7.
NG
6 Check operation of VSV for EGR (See page MF−44).
NG Replace VSV for EGR.
OK
Check for short in harness and connector be-
tween VSV and ECM (See page IN−26).
7 Check EGR vacuum modulator (See page MF−44).
NG Repair or replace.
OK