Page 460 of 2062

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
Page 470 of 2062

Downloaded from www.Manualslib.com manuals search engine DI−206
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
DTC P0402 Exhaust Gas Recirculation Flow Excessive
Detected*
*: Only for 2WD models with a load capacity of 0.5 ton and regular cab.
CIRCUIT DESCRIPTION
Refer to DTC P0401 on page DI−196.
DTC No.Detection ItemDTC Detecting ConditionTrouble AreaTrouble Area
P0402
EGR gas temp. sensor value is high during EGR cut−off
when engine is cold (Race engine at about 4,000 rpm
without load so that vacuum is applied to port E)
(2 trip detection logic)EGR valve stuck open
VSV for EGR open malfunction
Open in VSV circuit for EGR
Short in EGR gas temp. sensor circuit
ECM
P0402EGR valve is always open (2 trip detection logic)
WIRING DIAGRAM
Refer to DTC P0401 on page DI−196.
SYSTEM CHECK DRIVING PATTERN
Refer to DTC P0401 on page DI−196.
INSPECTION PROCEDURE
TOYOTA hand−held tester:
1 Connect TOYOTA hand−held tester and read 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.: 159°C (318.2°F) or less (Not immediately after driving)
HINT:
If there is a short circuit, the TOYOTA hand−held tester indicates 159.3°C (318.7°F).
OK Go to step 4.
NG
DI0UY−01
Page 477 of 2062
Downloaded from www.Manualslib.com manuals search engine S00594
Vapor Pressure SensorECM
From
Battery
From
IG SwitchII
IDIM12H
2D2C
2BE7
E6
E7
E6
E6 3
92
25
12 3
AA2 1
8 2 1 VSV (for EVAP)
VSV
(for Vapor
Pressure Sensor) LG
W−B B−O BP L−R
BR13
22 3
2
1
10
IGN
Instrument
Panel J/BDriver Side J/B
EFI Relay
EB
J/B
No.3VC
E2
E1
E01
E01 TPC EVP 1PTNK
BR
EFI
A
12 LGW−L 3
B−O5 V
− DIAGNOSTICSENGINE (5VZ−FE)
DI−213
1996 TOYOTA T100 (RM449U)
WIRING DIAGRAM
INSPECTION PROCEDURE
TOYOTA hand−held tester:
1 Check VSV connector for EVAP, VSV connector for vapor pressure sensor and
vapor pressure sensor connector for looseness and disconnection.
NG Repair or connect VSV or sensor connector.
OK
Page 490 of 2062

Downloaded from www.Manualslib.com manuals search engine FI7112 FI7166
A00081
T/M
Cable
Combination
MeterECM 4−pulseTo Speedometer Cable
No.1 Vehicle Speed SensorMagnet Reed Switch
S05704
Combination Meter
Speed
SensorFrom Cruise
Control ECUECM
E4 E4
(M/T)(A/T)812
6
C11GG
G
5 V
SP1
E1 DI−226
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
DTC P0500 Vehicle Speed Sensor Malfunction
CIRCUIT DESCRIPTION
This sensor is mounted in the combination meter. It contains a magnet which is rotated by the speed meter
cable.
Turning the reed switch ON and OFF 4 times for every revolution of the speedmeter.
It is then transmitted to the ECM. The ECM determines the vehicle speed based on the frequency of these
pulse signals.
DTC No.DTC Detecting ConditionTrouble Area
P0500
No speed sensor signal to ECM under conditions (a)
(2 trip detection logic)
(a) Vehicle is being drivenOpen or short in No.1 vehicle speed sensor circuit
No.1 vehicle speed sensor
ECM
Speedometer cable
WIRING DIAGRAM
DI0V3−01
Page 492 of 2062

Downloaded from www.Manualslib.com manuals search engine P01559
Throttle Valve
From
Air
Cleaner
Signal
ECM
ValveIAC Valve
To Cylinders Intake Air Chamber
P19957
ECM
RSC
RSOE01
E01 B−R
BR−R6
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 3 B−W
22 2
5 1
1 2
2 B−YEA1
W−R
B−Y
4
IGNJ/B
No.11A
1C 3
1722
23 DI−228
− DIAGNOSTICSENGINE (5VZ−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 and a VSV for idle−
up control is also added (for air conditioning).
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
Open or short in A/C signal circuit
Air intake (hose loose)
WIRING DIAGRAM
DI0V4−01
Page 495 of 2062
Downloaded from www.Manualslib.com manuals search engine P19954
− DIAGNOSTICSENGINE (5VZ−FE)
DI−231
1996 TOYOTA T100 (RM449U)
DTC P0510 Closed Throttle Position Switch Malfunction
CIRCUIT DESCRIPTION
Refer to Throttle/ Pedal Position Sensor/ Switch ”A” Circuit Malfunction on page DI−163.
DTC No.DTC Detecting ConditionTrouble Area
P0510The closed throttle position switch does not turn ON even once
when the vehicle is driven (2 trip detection logic)Open in closed throttle position switch circuit
Closed throttle position switch
ECM
HINT:
After confirming DTC P0510 use the TOYOTA hand−held tester to confirm the closed throttle position switch
signal from ”CURRENT DATA”.
Throttle ValveClosed throttle position Switch SignalMalfunction
Fully ClosedOFFOpen Circuit
Fully OpenONShort Circuit
WIRING DIAGRAM
DI9AF−01
Page 500 of 2062
Downloaded from www.Manualslib.com manuals search engine S00903
Battery W−R
W−R R−L WAM2
2
24
3R/B 8
IA3Switch IG
B−R
IE1
B−L
BR−B
B−W
B−Y
BRInjector
No.1
No.2
No.3
EB
8B−R
714
No.2Spark
PlugB−RB−RECM
Ignition
Coil
B−R
BR−Y
BR−W
B−R
B−R
B−W
2 1
2 1
2 1
10
2
1
3
8 4 5 6 7 9
To
Tachometer
(M/T)(A/T)
E7 E7
E7 E7
E7 E7
E7 E7IGT1 23 24
22 25
21 26
17 12IGT2
IGT3
IGF5 V
DI−236
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check spark plug (See page IG−1).
NG Go to step 4.
OK
Page 505 of 2062
Downloaded from www.Manualslib.com manuals search engine − DIAGNOSTICSENGINE (5VZ−FE)
DI−241
1996 TOYOTA T100 (RM449U)
DTC P1335 Crankshaft Position Sensor Circuit
Malfunction (during engine running)
CIRCUIT DESCRIPTION
Refer to DTC P0335 on page DI−191.
DTC No.DTC Detecting ConditionTrouble Area
P1335No crankshaft position sensor signal to ECM with engine
speed 1,000 rpm or more
Open or short in crankshaft position sensor circuit
Crankshaft position sensor
Starter
ECM
WIRING DIAGRAM
Refer to DTC P0335 on page DI−191.
INSPECTION PROCEDURE
Refer to DTC P0335 on page DI−191.
DI0V6−01