BAT TOYOTA LAND CRUISER 1996 J80 Repair Manual

−
DIAGNOSTICS ENGINE
DI−7
1996 LAND CRUISER (RM451U)
(10) After checking the DTC, inspect the applicable cir-
cuit.
(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 LOCK 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 5 ° BTDC
 Injection method fixed at simultaneous injectionReturned 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°
The following condition must be repeated at least 2 times
consecutively
When closed throttle position switch is ON:
0.1 V  VTA  0.95 V
P0135
P0141The heater circuit in witch an abnormality is detected is
turned offIgnition switch OFF
P0325
P0330Max. timing retardationIgnition switch OFF
P1300Fuel cutIGF signal is detected for 6 consective ignitions
P1605Max. timing retardationReturned to normal condition
5. CHECK FOR INTERMITTENT PROBLEMS
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.
(1) Clear the DTC (See step 2).
(2) Set the check mode (See step 3).
(3) Perform a simulation test (See page IN−18).
(4) Check the connector and terminal (See page IN−28).
(5) Handle the connector (See page IN−28).
(6) Visual check and contact pressure (See page IN−28).
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P04771
InsideOutside
DI−8
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
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 problem\
s. 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.
YES
2 Is engine cranked?
NO Proceed to page ST−16 , and continue to trouble-
shoot.
YES
3 Does engine start?
NO Go to step 7.
YES
4 Check air filter.
PREPARATION:
Remove air filter.
CHECK:
Visually check that the air cleaner element is not dirty or exces-
sive oily.
HINT:
If necessary, clean the element with compressed air. First blow
from inside thoroughly, then blow from outside of element.
NG Repair or replace
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P09401
P22893
DI−10
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
OK
Proceed to matrix chart of problem symp-
toms on page DI−19.
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 ignition switch ON and push TOYOTA hand −held
tester main switch ON.
(d) Use ACTIVE TEST mode to operate the fuel pump.
(e) 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−6).
CHECK:
Check for fuel pressure in the fuel return hose when it is pinched
off.
HINT:
At this time, you will hear a fuel flowing noise.
NG Proceed to page SF−6 and continue to trouble-
shoot.
OK
8 Check for spark.
PREPARATION:
(a) Remove No.2 and No.3 cylinder head cover.
(b) Disconnect high −tension cord from spark plug.
(c) Remove spark plug.
(d) Install the spark plug to the high −tension cord.
(e) Ground the spark plug.
(f) Disconnect injector connector.
CHECK:
Check if spark occurs while engine is being cranked.
NOTICE:
To prevent excess fuel being injected from the injectors
during this test, don’t crank the engine for more than 5 − 10
seconds at a time.
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−
DIAGNOSTICS ENGINE
DI−15
1996 LAND CRUISER (RM451U)
DTC No.
(See Page)
Detection ItemTrouble Area*MILMemory
P0420
( DI−84 )Catalyst System Efficiency
Below Threshold Three− way catalytic convertor
 Open or short in heated oxygen sensor circuit
 Heated oxygen sensor

P0500
( DI−87 )Vehicle Speed Sensor
Malfunction
Combination meter
 Open or short in speed sensor circuit
 ECM
 Vehicle speed sensor

P0505
( DI−89 )Idle Control System
Malfunction
IAC valve is stuck or closed
 Open or short in IAC valve circuit
 Open or short A/C signal circuit
 Air intake (hose loose)

P0510
( DI−93 )Closed Throttle Position
Switch MalfunctionOpen in closed throttle position switch circuit
 Closed throttle position switch
 ECM

P1300
( DI−97 )Igniter Circuit Malfunction
Open or short in IGF or IGT circuit from igniter to ECM
 Igniter
 ECM

P1335
( DI−102 )Crankshaft Position Sensor
Circuit Malfunction
(during engine running)
Open or short in crankshaft position sensor circuit for NE sig-
nal
 Crankshaft position sensor for NE signal
 Starter
 ECM
−
P1500
( DI−103 )Stater signal circuit MalfunctionOpen or short in starter signal circuit
 ECM−
P1600
( DI−105 )ECM BATT MalfunctionOpen in back up power source circuit
 ECM
P1605
( DI−107 )Knock Control CPU MalfunctionECM
P1780
( DI−108 )Park/Neutral Position Switch
MalfunctionShort in park/neutral position switch circuit
 Park/neutral position switch
 ECM

*: −  MIL does not light up,   MIL lights up
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DI5OX−03
FI6526
12345678910
11
1213
1415161718192021222324252612345678
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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P22419
WR−Y
GECM
Y−R R
R
BR
Battery Fusible Link
EFI
R/B No.2
EFI Main
Relay
Y−R
FL MAIN
BR
1
Mass Air Flow
Meter
2
2 2
2 2
2
1 1
1
F8 2
4
3 E7
E5
E5 VGMRLY
2
23
7
5 16B+
E1
EB
E21
EB1 EA2
−
DIAGNOSTICS ENGINE
DI−21
1996 LAND CRUISER (RM451U)
WIRING DIAGRAM
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P22423
2
1 3
4
13
24
O
2
2
22 2
2
EB1
EA2
EFI
BR
R−Y
Y−RR
Y−R
1 7
R 3
5
1
E7
E5
E5
EFI Main
Relay
From BatteryEB
R/B No.2
14
32
BR−B
BR−B
BR−B WL
GR E6
E4E6
MRLY
B+
HT1
OX2
E1
HT2 E03
OX1
Heated Oxygen Sensor
(bank 1 sensor 1)
Heated Oxygen Sensor
(bank 1 sensor 2)
ECM
Y−R
Y−R
EC
32
14
E1E03
E1
7
−
DIAGNOSTICS ENGINE
DI−41
1996 LAND CRUISER (RM451U)
HINT:
After confirming DTC P0125 use the OBD II scan tool or TO YOTA handheld tester to confirm voltage output
of heated oxygen sensor (bank 1 sensor 1) from CURRENT DATA.
If voltage output of heated oxygen sensor (bank 1 sensor 1) is 0 V, heated oxygen sensor (bank 1 sensor
1) circuit may be open or short.
WIRING DIAGRAM
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P22424
Fusible Link
Battery
FL AM2
F7
EA2
6
11
3
1 IG Switch
W−RW
−R
B−R B−R
IH1
14B−R
B−R
B−R
B−R
B−R B−R 2
2
2
2
2
2 1
1
1
1
1
1 W−L
W−R
W−G Y
Y−R
Y−L
BR
BR E4
E4
E4
E4
E4 E4
E4
E4 11 12
25 2
1
15
13
26
EC
Injector #10
#20 #30
#40
#50
#60
E01
E02 ECM
No.1
No.2
No.3
No.4
No.5
No.6
FI6588 FI6538
A00064
10V/
Division
GND 10V/
Division
100 m sec./Division (Idling) GND(Magnification)
1 m sec./Division (Idling)
Injection duration
−
DIAGNOSTICS ENGINE
DI−55
1996 LAND CRUISER (RM451U)
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.
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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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P22474
EBBR
22 22
1 3
4
2 2
2
R−Y R/B No.2
From BatteryR
Y−R
EA2
EB1
Y−RY −R
Y−R R
R−G
R−B
G−Y
Y−L
4
1
3 6
IAC Valve MRLY
E7
E4
E4
E4
E4 7 3
6
5
4
ISC1
ISC2
ISC3
ISC4 B+
E01
E01
E01
E01
EFI
2
5
EFI Main
Relay
7
1 ECM
A00202
ISC1
ISC2
ISC3
ISC4 A/C Switch OFF
→ ON
(IAC Valve Open)
20 V/Division
10 msec./Division
ISC1
ISC2
ISC3
ISC4 20 V/
Division
10 msec./Division
(IAC Valve Close)
A/C Switch ON →
OFF
FI6536
FI6537
DI−90
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
WIRING DIAGRAM
Reference: INSPECTION USING OSCILLOSCOPE
With the engine idling measure wavefoms between terminals
ISC1, ISC2, ISC3, ISC4 and E01 of ECM when A/C switch ON
or OFF.
HINT:
The correct waveforms are as shown.
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