Downloaded from www.Manualslib.com manuals search engine A00653
w/o Tachometer
w/ Tachometer
− DIAGNOSTICSENGINE (5VZ−FE)
DI−131
1996 TOYOTA T100 (RM449U) Terminal No.
Connection / Voltage or ResistanceCondition
2Bus Line / Pulse generationDuring transmission
4Chassis Ground ↔ Body Ground / 1 Ω or lessAlways
5Signal Ground ↔ Body Ground / 1 Ω or lessAlways
16Battery Positive ↔ Body Ground / 9 − 14 VAlways
HINT:
If your display shows ”UNABLE TO CONNECT TO VEHICLE”
when you have connected the cable of the OBD II scan tool or
TOYOTA hand−held tester to DLC3, turned the ignition switch
ON and operated the scan tool, there is a problem on the ve-
hicle side or tool side.
If communication is normal when the tool is connected to
another vehicle, inspect DLC3 on the original vehicle.
If communication is still not possible when the tool is con-
nected to another vehicle, the problem is probably in the
tool itself, so consult the Service Department listed in the
tool’s instruction manual.
2. INSPECT DIAGNOSIS (Normal Mode)
(a) Check the MIL
(1) The MIL comes on when the ignition switch is turned
ON and the engine is not running.
HINT:
If the MIL does not light up, troubleshoot the combination meter
(See page BE−36).
(2) When the engine started, the MIL should go off. If
the lamp remains on, the diagnosis system has de-
tected a malfunction or abnormality in the system.
(b) Check the DTC.
NOTICE:
TOYOTA hand−held tester only: When the diagnosis sys-
tem is switched from normal mode to check mode, it erases
all DTCs and freezed frame data recorded in normal mode.
So before switching modes, always check the DTCs and
freezed frame data, and note them down.
(1) Prepare the OBD II scan tool (complying with SAE
J1978) or TOYOTA hand−held tester.
(2) Connect the OBD II scan tool or TOYOTA hand−
held tester to the DLC3 at the lower of the instru-
ment panel.
(3) Turn the ignition switch ON and push the OBD II
scan tool or TOYOTA hand−held tester switch ON.
(4) Use the OBD II scan tool or TOYOTA hand−held
tester to check the DTCs and freezed frame data,
note them down. (For operating instructions, see
the OBD II scan tool’s instruction book.)
(5) See page DI−129 to confirm the details of the
DTCs.
Downloaded from www.Manualslib.com manuals search engine FI3605
Flashing
ON
OFF
0.13 Seconds
DI−132
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
NOTICE:
When simulating symptoms with an OBD II scan tool (ex-
cluding TOYOTA hand−held tester) to check the DTCs, use
normal mode. For code on the DTC chart subject to ”2 trip
detection logic”, turn the ignition switch OFF after the
symptom is simulated the 1st time. Then repeat the simula-
tion process again. When the problem has been simulated
twice, the MIL lights up and the DTCs are recorded in the
ECM.
3. INSPECT DIAGNOSIS (Check Mode)
HINT:
TOYOTA hand−held tester only:
Compared to the normal mode, the check mode has an in-
creased sensitivity to detect malfunctions.
Furthermore, the same diagnostic items which are detected in
the normal mode can also be detected in the check mode.
(a) Check the DTC.
(1) Initial conditions
Battery positive voltage 11 V or more
Throttle valve fully closed
Transmission in ”P” or ”N” position
Air conditioning switched OFF
(2) Turn the ignition switch OFF.
(3) Prepare the TOYOTA hand−held tester.
(4) Connect the TOYOTA hand−held tester to DLC3 at
the lower of the instrument panel.
(5) Turn the ignition switch ON and push the TOYOTA
hand−held tester switch ON.
(6) Switch the TOYOTA hand−held tester normal mode
to check mode (Check that the MIL flashes.).
(7) Start the engine. (The MIL goes out after the engine
start.)
(8) Simulate the conditions of the malfunction de-
scribed by the customer.
NOTICE:
Leave the ignition switch ON until you have checked the
DTCs, etc.
(9) After simulating the malfunction conditions, use the
TOYOTA hand−held tester diagnosis selector to
check the DTCs and freezed frame data, etc.
HINT:
Take care not to turn the ignition switch OFF. Turning the ignition
switch OFF switches the diagnosis system from check mode to
normal mode. so all DTCs, etc. are erased.
(10) After checking the DTC, inspect the applicable cir-
cuit.
Downloaded from www.Manualslib.com manuals search engine − DIAGNOSTICSENGINE (5VZ−FE)
DI−133
1996 TOYOTA T100 (RM449U)
(b) Clear the DTC.
The following actions will erase the DTCs and freezed
frame data.
(1) Operating the OBD II scan tool (complying with SAE
J1978) or TOYOTA hand−held tester to erase the
codes (See the OBD II scan tool’s instruction book
for operating instructions.).
(2) Disconnecting the battery terminals or EFI fuse.
NOTICE:
If the TOYOTA hand−held tester switches the ECM from
normal mode to check mode or vice−versa, or if the igni-
tion switch is turned from ON to ACC or OFF during check
mode, the DTCs and freezed frame data will be erased.
4. FAIL−SAFE CHART
If any of the following codes is recorded, the ECM enters fail−safe mode.
DTC No.Fail−Safe OperationFail−Safe Deactivation Conditions
P0100Ignition timing fixed at 10° BTDCReturned to normal condition
P0110Intake air temp. is fixed at 20°C (68°F)Returned to normal condition
P0115Engine coolant temp. is fixed at 80°(176°F)Returned to normal condition
P0120VTA is fixed at 0°
Following condition must be repeated at least 2 times
consecutively
0.1 V VTA 0.95 V
P0135
P0141Heater circuit in which an abnormality is detected is
turned offIgnition switch OFF
P0325
P0330Max. timing retardationIgnition switch OFF
P1300Fuel cutIGF signal is detected for 6 consective ignitions
5. CHECK FOR INTERMITTENT PROBLEMS
HINT:
TOYOTA HAND−HELD TESTER only:
By putting the vehicle’s ECM in check mode, 1 trip detection logic is possible instead of 2 trip detection logic
and sensitivity to detect open circuits is increased. This makes it easier to detect intermittent problems.
(a) Clear the DTCs (See step 3).
(b) Set the check mode (See step 3).
(c) Perform a simulation test (See page IN−16).
(d) Check the connector and terminal (See page IN−26).
(e) Handle the connector (See page IN−26).
6. BASIC INSPECTION
When the malfunction code is not confirmed in the DTC check, troubleshooting should be performed in the
order for all possible circuits to be considered as the causes of the problems. In many cases, by carrying
out the basic engine check shown in the following flow chart, the location causing the problem can be found
quickly and efficiently. Therefore, use of this check is essential in engine troubleshooting.
1 Is battery positive voltage 11 V or more when engine is stopped?
NO Charge or replace battery.
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ON
Fuel Inlet Hose
DI−136
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
7 Check fuel pressure.
PREPARATION:
(a) Be sure that enough fuel is in the tank.
(b) Connect the TOYOTA hand−held tester to the DLC3.
(c) Turn the ignition switch ON and push the TOYOTA hand−
held tester main switch ON.
(d) Use ”ACTIVE TEST” mode to operate the fuel pump.
(e) Please refer to the TOYOTA hand−held tester operator’s
manual for further details.
(f) If you have no TOYOTA hand−held tester, connect the
positive (+) and negative (−) leads from the battery to the
fuel pump connector (See page SF−5).
CHECK:
Check for fuel pressure in the fuel inlet hose when it is pinched
off.
HINT:
At this time, you will hear a fuel flowing noise.
NG Proceed to page SF−5 and continue to trouble-
shoot.
OK
Downloaded from www.Manualslib.com manuals search engine P19917
From
IG Switch
Mass Air Flow MeterBattery
R/B No.2
J/B No.1B−W
W−R
B−YEFI
IGN
EFI RelayW−R
B−Y
W−B
EA1EA1
IE1
W−R W−R
1A1C
EA
1
2
222
2
12
2
2 3 2
4
17
31
2
52
E6 E6
E6 E68
818
GR−R
BR−W
(M/T)(A/T)
VG
E3
E1
W
9
9ECM
DI−150
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Connect OBD II scan tool or TOYOTA hand−held tester and read value of mass
air flow rate.
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand−held tester to the DLC3.
(b) Turn the ignition switch ON and push the OBD II scan tool or TOYOTA hand−held tester main switch
ON.
(c) Start the engine.
CHECK:
Read mass air flow rate on the OBD II scan tool or TOYOTA hand−held tester.
RESULT:
Type IType II
Mass air flow rata (gm/sec.)Approx. 011.0 − 25.1 (idling after warming up)
Type I Go to step 2.
Type II Go to step 5.
Downloaded from www.Manualslib.com manuals search engine P19611
R/B No.2
B−W
22E6 E6
E6 E6
BRE1 E1
EB
2
2
22
From Battery
To Body GroundFrom
IG Switch
EFI RelayW−R
EFI
2
2
15 13EA1IE1 W−RW−RW−R 99
W−R
Heated
Oxygen
Sensor
(Bank 1
Sensor 2)2
13
423
14Heated
Oxygen
Sensor
(Bank 1
Sensor 1)
P−G
E5 E7
E7
E5
E5 E7 R−G RECM
OX1
HT1
OX2
E1
HT2E03
E03 (M/T)(A/T)5
3
13
24
913
16
19
16
15 W
BR BR
BR
DI−170
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
HINT:
After confirming DTC P0125 use the OBD II scan tool or TOYOTA hand−held tester to confirm voltage output
of heated oxygen sensor from "CURRENT DATA".
If voltage output of heated oxygen sensor is 0 V, heated oxygen sensor circuit may be open or short.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Connect OBD II scan tool or TOYOTA hand−held tester and read value for
voltage output of heated oxygen sensor (bank 1 sensor 1).
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand−held tester to the DLC3.
(b) Warm up the engine to normal operating temp.
CHECK:
Read voltage output of heated oxygen sensor (bank 1 sensor 1) when engine is suddenly raced.
HINT:
Perform quick racing to 4,000 rpm 3 times using the accelerator pedal.
OK:
Heated oxygen sensor (bank 1 sensor 1) output a RICH signal (0.45 V or more) at least once
OK Check and replace ECM (See page IN−26).
NG
Downloaded from www.Manualslib.com manuals search engine S00901
Battery W−RW−R
R−L W
AM2
2
2 4
3R/B No.28
IA3
8
7Switch IG
B−R
IE114
B−R
B−RB−R
B−R 2
B−R 2
B−R 2
B−R 2
B−R 2
B−R 2Injector
No.1
No.2
No.3
No.4
No.5
No.61
1
1
1
1
1W−R
W
W−G
Y−R
W−L
Y−B
BR
BRE7 E7
E7 E7
E7 E7
E7 E7
E7 E7
E7 E7
E7 E7
E7 E7
(M/T)(A/T)
EB
12 10
11 9
25 8
10 7
96
85
13 34
26 33#10
#20
#30
#40
#50
#60
E01
E02ECM
FI6588
FI6538
A00064
10 V
/Division10 V
/Division
GND GND
100 msec./Division (Idling)1 msec./Division (Idling)
Injection duration
(Magnification)
DI−184
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
WIRING DIAGRAM
Reference INSPECTION USING OSCILLOSCOPE
INJECTOR SIGNAL WAVEFORM
With the engine idling, measure between terminals #10 − #60 and E01 of ECM.
HINT:
The correct waveform is as shown.
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