1996 TOYOTA LAND CRUISER Vacuum

DI5OX−03
FI6526
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11
1213
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910
11
1213141516 123456
78
910
11
12 12345678910
11
1415161718192021221213
E4 E5E6 E7
ECM Terminals
−
DIAGNOSTICS ENGINE
DI−17
1996 LAND CRUISER (RM451U)
TERMINALS OF ECM
Symbols (Terminals No.)Wiring ColorConditionSTD Voltage (V)
BATT (E7 − 2) − E1 (E4 − 24)R − Y ↔ BR − BAlways9 − 14
+ B (E7 − 12) − E1 (E4 − 24)Y ↔ BR − BIG switch ON9 − 14
VCC (E5 − 1) − E2 (E5 − 9)R − G ↔ BR − BIG switch ON4.5 − 5.5
IDL (E5 − 11) − E2 (E5 − 9)G − W ↔ BR − B
IG switch ON and apply vacuum to the throttle opener
Throttle valve fully closed0 − 3
IG switch ON
Throttle valve fully open9 − 14
VTA (E5 − 10) − E2 (E5 − 9)G − B↔ BR − B
IG switch ON
Throttle valve fully closed0.3 − 0.8
IG switch ON
Throttle valve fully open3.2 − 4.9
VG (E5 − 2) − E21 (E5 − 16)G − BRIdling, N position, A/C switch OFF1.1 − 1.5
THA (E5 − 3) − E2 (E5 − 9)L − Y ↔ BR − BIdling, Intake air temp. 20° C (68° F)0.5 − 3.4
THW (E5 − 4) − E2 (E5 − 9) R − W↔BR − BIdling, Engine coolant temp. 80 °C (176°F)0.2 − 1.0
STA (E7 − 11) − E1 (E4 − 24)B − R ↔ BR − BCranking6.0 or more
#10 (E4 − 12) − E01 (E4 − 13)W − L ↔ BR
IG switch ON9 − 14
IdlingPulse generation
(See page DI−54)
#20 (E4 − 11) − E01 (E4 − 13)W − R ↔ BR
IG switch ON9 − 14
IdlingPulse generation
(See page DI−54)
#30 (E4 − 25) − E01 (E4 − 13)W − G ↔ BR
IG switch ON9 − 14
IdlingPulse generation
(See page DI−54)
#40 (E4 − 2) − E01 (E4 − 13)Y ↔ BR
IG switch ON9 − 14
IdlingPulse generation
(See page DI−54)
#50 (E4 − 1) − E01 (E4 − 13)Y − R ↔ BR
IG switch ON9 − 14
IdlingPulse generation
(See page DI−54)
#60 (E4 − 15) − E01 (E4 − 13)Y − L ↔ BR
IG switch ON9 − 14
IdlingPulse generation
(See page DI−54)
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P22417
Exhaust
Gas
Intake Air
Chamber EGR
Valve
VSV
EGR
Vacuum
Modulator
ECM
Throttle
valve
P22426
BR
From Battery R/B No.2
R−Y
2
222
2
2
Y−R
EFI Main
Y−R
1
2
43
REA2
EZ1
EB12 7
VSV for EGR 21
YYL
−W
EZ14
EGR Gas T emp.
Sensor
21
G−Y
BR−BE7 E4
E4
E5 3
22
19
9
THG
E1
EGR
E2 5V
MRLY
ECM
R
EB
EFI
1
Relay
B+
E01
−
DIAGNOSTICS ENGINE
DI−69
1996 LAND CRUISER (RM451U)
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 combust\
ion temp. and reduce NOx
emissions. The amount of EGR is regulated by the EGR vacuum modulator ac\
cording 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 the engine is warmed up and run at 80 km/h (50 mph)
for 3 to 5 minutes, the EGR gas temperature sensor value
does not exceed 38° C (100.4°F) above the ambient air tem-
perature. (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
DI5PK−02
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A00169
ON
EGR Gas Temp.
Sensor ECM
1
2 19
9
THG E2
BE6653
FI7057
P22167 E4
E5
THG E2 5V
DI−72
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
3 Check for open in harness or ECM.
PREPARATION:
(a) Remove the instrument panel speaker No.1 panel (See
page SF−65 ).
(b) Connect between terminals THG and E2 of ECM connec-
tor.
HINT:
EGR gas temp. sensor connector is disconnected.
Before checking, do a visual check and contact pressure check
for the ECM connector (See page IN−28).
CHECK:
Read EGR gas temp. on the TOYOTA hand−held tester.
OK:
EGR gas temp.: Approx. 157.5° C (315.5°F)
OK Open in harness between terminals E2 or THG. Repair or replace harness.
NG
Confirm connection at ECM.
If OK, replace ECM (See page IN−28).
4 Check the connection of the vacuum hose, EGR hose (See page EC−11).
NG Repair or replace.
OK
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A00170
System : ON
System : OFF Air
GE
Air GE
P22963
P22964
−
DIAGNOSTICS ENGINE
DI−73
1996 LAND CRUISER (RM451U)
5 Check the VSV for EGR.
PREPARATION:
(a) Remove the fuse cover on the instrument panel.
(b) Connect the TOYOTA hand−held tester to the DLC3.
(c) Turn ignition switch ON and TOYOTA hand −held tester
main switch ON.
(d) 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 ON:
Air does not flow from pipe G to pipe E.
EGR system is OFF:
Air from pipe G is flowing out through pipe E.
OK Go to step 7.
NG
6 Check operation of the VSV for EGR (See page SF−60).
NG Replace VSV for EGR.
OK
Check for open in harness and connector be-
tween VSV and ECM (See page IN−28).
7 Check EGR vacuum modulator (See page EC−11 ).
NG Repair or replace.
OK
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A00172
ON
THG E2 (+)(−)
BE6653
P24667
DI−76
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
3 Check for open in harness or ECM.
PREPARATION:
(a) Remove instrument panel speaker No.1 panel (See page
SF−65 ).
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminals of THG and E2 of ECM
connector.
HINT:
EGR gas temp. sensor connector is disconnected.
OK:
Voltage: 4.5 − 5.5 V
OK Open in harness between terminals E2 or THG. Repair or replace harness.
NG
Confirm connection at ECM.
If OK, replace ECM (See page IN−28).
4 Check connection of vacuum hose, EGR hose (See page EC−11).
NG Repair or replace.
OK
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DI−78
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
6 Check operation for the VSV for EGR (See page SF−60).
NG Replace VSV for EGR.
OK
Check for open in harness and connector be-
tween R/B No.2 and ECM (See page IN−28).
7 Check EGR vacuum modulator (See page EC−11 ).
NG Repair or replace.
OK
8 Check EGR valve (See page EC−11 ).
NG Repair or replace.
OK
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DI−80
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
DTC P0402 Exhaust Gas Recirculation Flow Excessive Detected
CIRCUIT DESCRIPTION
Refer to DTC P0401 (Exhaust Gas Recirculation Flow Insufficient Detected) on page DI−69.
DTC No.DTC Detecting ConditionTrouble 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
 EGR VSV open malfunction
 Open in VSV circuit for EGR
 Short in EGR gas temp. sensor circuit
 ECM
EGR valve is always open (2 trip detection logic)
Refer to DTC P0401 (Exhaust Gas Recirculation Flow Insufficient Detected) for the System Check Driving
Pattern and Wiring Diagram.
INSPECTION PROCEDURE
TOYOTA hand −held tester
1 Connect the TOYOTA hand −held tester and read EGR gas temp. value.
PREPARATION:
(a) Remove the fuse cover on the instrument panel.
(b) Connect the TOYOTA hand−held tester to the DLC3.
(c) Turn 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.: 150° C (302°F) or less (Not immediately after driving)
HINT:
If there is a short circuit, the TOYOTA hand−held tester indicates Approx. 157.5°C (315.5°F).
OK Go to step 4.
NG
DI5PL−02
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EC−8
−
EMISSION CONTROL EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
1996 LAND CRUISER (RM451U)
16. REMOVE TVV FROM CYLINDER HEAD
(a) Disconnect the 2 vacuum hoses.
(b) Remove the TVV.
17. INSPECT TVV OPERATION
(a) Cool the TVV to below 45° C (113°F) with cool water.
(b) Check that air flows from pipe J to the air filter.
(c) Heat the TVV to above 64° C (147°F) with hot water.
(d) Check that air flows from pipe J to pipe K.
If operation is not as specified, replace the TVV.
18. REINSTALL TVV
(a) Apply adhesive to 2 or 3 threads of the TVV, and install it.
Adhesive:
Part No. 08833 −00070, THREE BOND 1324
or equivalent
Torque: 29 N·m (300 kgf·cm, 22 ft·lbf)
(b) Reconnect 2 vacuum hoses.
19. REFILL WITH ENGINE COOLANT
20. REMOVE INTAKE MANIFOLD STAY
21. REMOVE VCV
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