Page 309 of 2062

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 From
IG Switch
EFI RelayW−R
EFI2
1 5 13EA1
IE1 W−RW−RW−R 9
9
W−R
Heated
Oxygen
Sensor
(Bank 1
Sensor 2)2
13
423
14Heated
Oxygen
Sensor
(Bank 1
Sensor 1)
P−G
E7 E7
E7 E7
E7 E7 R−G WECM
OX1
HT1
OX2
E1
HT2E03
E03 (M/T)(A/T)6
2
5
14
155
3
13
24
16 B
To Body Ground
− DIAGNOSTICSENGINE (3RZ−FE)
DI−45
1996 TOYOTA T100 (RM449U)
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Connect OBD II scan tool or TOYOTA hand−held tester and read value for volt-
age 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
Page 323 of 2062
Downloaded from www.Manualslib.com manuals search engine S00877
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.
Page 336 of 2062

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
Page 352 of 2062

Downloaded from www.Manualslib.com manuals search engine A00652
ECM VSV for EVAP
Throttle
Valve
Fuel Tank Charcoal
CanisterFig 1
A00647
IG Switch
(M/T)(A/T)
23W−G
2
1
EFI
EFI Relay
VSV for
ECM From From
Battery
22
2
2
223 2
E7 E5
EA
W−B
IE2W−G1 R/B No.2
PRG
E01 4EVAP5
EA1
W−RW−R
921
B−W
DI−88
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
DTC P0441 Evaporative Emission Control System
Incorrect Purge Flow
CIRCUIT DESCRIPTION
To reduce HC emissions, evaporated fuel from the fuel tank is
routed through the charcoal canister to the intake manifold for
combustion in the cylinders.
The ECM changes the duty signal to the VSV for EVAP so that
the intake quantity of HC emissions is appropriate for the driving
conditions (engine load, engine speed, vehicle speed, etc.) af-
ter the engine is warmed up.
DTC No.DTC Detecting ConditionTrouble Area
P0441Proper response to computer command does not occur
(2 trip detection logic)
Open or short in VSV circuit for EVAP
VSV for EVAP
ECM
Vacuum hose cracks, hole, blocked, damaged or
disconnected
Charcoal canister
WIRING DIAGRAM
DI0TX−03
Page 358 of 2062

Downloaded from www.Manualslib.com manuals search engine P01559
Throttle Valve
To Cylinder ECM
Signal
From
Air
Cleaner
Valve
IAC Valve
Intake Air
Chamber
P19957
ECM
RSC
RSOE01
E01 V−Y
V−R96
10 7 E7 E7
E7 E7
(M/T)(A/T)
3
1 IAC
Valve
W−R IG Switch FromFrom Battery
R/B No.2EFI Relay
EFI2
IE1
EA1
W−R
9
9
EA
W−R
W−B 2
2
2 B−W
22
15 2
2
B−Y
EA1
W−R
B−Y
4
IGN
J/B
No.11A
1C 3
17
3 DI−94
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
DTC P0505 Idle Control System Malfunction
CIRCUIT DESCRIPTION
The rotary solenoid type IAC valve is located in front of the in-
take air chamber and intake air bypassing the throttle valve is
directed to the IAC valve through a passage.
In this way the intake air volume bypassing the throttle valve is
regulated, controlling the engine speed.
The ECM operates only the IAC valve to perform idle−up and
provide feedback for the target idling speed.
DTC No.DTC Detecting ConditionTrouble Area
P0505Idle speed continues to vary greatly from target speed
(2 trip detection logic)IAC valve is stuck or closed
Open or short in IAC valve circuit
Air intake (hose loose)
WIRING DIAGRAM
DI0TZ−03
Page 367 of 2062

Downloaded from www.Manualslib.com manuals search engine S00874
IG Switch
(M/T)(A/T)
23ECM
E7 E7 1
AM2
IA3
8W−RW−R
8
2
27
B−R
R−L
W Battery
IE1R/B No.2B−R
B−R
25 V
Tr
1
20
317
E7 E7 14B−L
B−Y2
1 Tr
2
3 4
Tachometer To To
Spark plug
B−W
Igniter IgnitionCoil
IGT
IGF 5
− DIAGNOSTICSENGINE (3RZ−FE)
DI−103
1996 TOYOTA T100 (RM449U)
DTC P1300 Ignition Circuit Malfunction
CIRCUIT DESCRIPTION
The ECM determines the ignition timing, turns on Tr1 at a predetermined angle (°CA) before the desired igni-
tion timing and outputs an ignition signal (IGT) ”1” to the igniter.
Since the width of the IGT signal is constant, the dwell angle control circuit in the igniter determines the time
the control circuit starts primary current flow to the ignition coil based on the engine rpm and ignition timing
one revolution ago, that is, the time the Tr
2 turns on.
When it reaches the ignition timing, the ECM turns Tr
1 off and outputs the IGT signal ”0”.
This turns Tr
2 off, interrupting the primary current flow and generating a high voltage in the secondary coil
which causes the spark plug to spark. Also, by the counter electromotive force generated when the primary
current is interrupted, the igniter sends an ignition confirmation signal (IGF) to the ECM. The ECM stops fuel
injection as a fail safe function when the IGF signal is not input to the ECM.
DTC No.DTC Detecting ConditionTrouble Area
P1300No IGF signal to ECM for 4 consecutive IGT signal during
engine runningOpen or short in IGF or IGT circuit from igniter to ECM
Igniter
ECM
WIRING DIAGRAM
DI0U1−03
Page 374 of 2062

Downloaded from www.Manualslib.com manuals search engine P19741
ECM
STA
E1 E4
(M/T) (A/T)
11
E4 11
B−R
Starter IE1
B−R
B−RB−R B−R (M/T)
21 35
Starter
Relay 1
2
W−B (A/T)
IC
B (A/T) W
Park/Neutral
Position Switch
15
B
5
6 B−Y 22
IA3
AM1
W
ALT
BatteryR/B No. 2W−B (M/T)
Clutch
Start
SwtichIE1
B (M/T) B−Y
6 3 W
W
W
14IE1
2
2
2
2
W
DI−11 0
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
DTC P1500 Starter Signal Circuit Malfunction
CIRCUIT DESCRIPTION
When the engine is cranked, the intake air flow is slow, so fuel vaporazation is poor. A rich mixture is therefore
necessary in order to achieve good startability. While the engine is being cranked, the battery voltage is ap-
plied to terminal STA of the ECM. The starter signal is mainly used to increase the fuel injection volume for
the starting injection control and after−start injection control.
DTC No.DTC Detecting ConditionTrouble Area
P1500No starter signal to ECM
Open or short in starter signal circuit
Open or short in ignition swtich or starter relay circuit
ECM
HINT:
In this circuit, diagnosis can only be made in the check mode.
WIRING DIAGRAM
DI984−01
Page 376 of 2062
Downloaded from www.Manualslib.com manuals search engine S00876
W−RB−G
EFI
R/B No.2 22
W
8
EA1 IE1B−G
(M/T)17
B−G (A/T)B−G
(M/T)
E4 E42 1
(M/T)(A/T)ECM
BATT
Battery DI−11 2
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
DTC P1600 ECM BATT Malfunction
CIRCUIT DESCRIPTION
Battery positive voltage is supplied to terminal BATT of the ECM even when the ignition switch is OFF for
use by the DTC memory and air−fuel ratio adaptive control value memory, etc.
DTC No.DTC Detecting ConditionTrouble Area
P1600Open in back up power source circuitOpen in back up power source circuit
ECM
HINT:
If DTC P1600 appear, the ECM does not store another DTC.
WIRING DIAGRAM
DI0U4−03