1996 TOYOTA LAND CRUISER BAT

A15825
−
DIAGNOSTICS ENGINE
DI−103
1996 LAND CRUISER (RM451U)
DTC P1500 Starter Signal Circuit Malfunction
CIRCUIT DESCRIPTION
When the engine is cranked, the intake air flow is slow, so fuel vaporization is poor. A rich mixture is therefore
necessary in order to achieve good startability. While the engine is being cranked, the battery positive volt-
age is applied to terminal STA of the ECM. The starter signal is mainly used to increase the fuel inj\
ection
volume for the starting injection control and after −start injection control.
WIRING DIAGRAM
DI968−01
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Version 1.11 - 03/16/2010

P22477
BatteryFusible Link
E8
1 W
2 2
EFI
R/B No.2
R−YR−Y
EA2E7ECM
BATT
2
FL MAIN
2
−
DIAGNOSTICS ENGINE
DI−105
1996 LAND CRUISER (RM451U)
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
DI5PT−02
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Version 1.11 - 03/16/2010

BE6053P24676A08534
LOCK
(+)
(−)
BATT
P22346
R/B No.2
EFI Fuse
DI−106
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
INSPECTION PROCEDURE
1 Check voltage between terminal BATT of ECM connector and body ground.
PREPARATION:
Remove the instrument panel speaker No.1 panel
(See page SF−65 ).
CHECK:
Measure voltage between terminal BATT of ECM connector
and body ground.
OK:
Voltage 9 − 14 V
OK Check and replace ECM (See page IN−28 ).
NG
2 Check EFI fuse.
PREPARATION:
Remove EFI fuse from R/B No.2.
CHECK:
Check continuity of EFI fuse.
OK:
Continuity
NG Check for short in all the harness and components connected to EFI fuse.
OK
Check and repair harness or connector
between battery, EFI fuse and ECM.
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P22478
Battery
FL AM1
Fusible Link
1F6
B−L
2
2 2
2
3
4
AM1
R/B No.2
Junction
Connector (J4)
Y Y
IG Switch
4 2
1 B−W
B−YFuse Block
GAUGE
Y
B
B 6IH14
B−W Park/Neutral
Position Switch
3
2 G−R G−W
O
O
IH2
To A/T Indicator Light
(Combination Meter)
Starter
1
S1 E7
E7
E7
17
16
22 NSW
E1B+
E1 E1
L
2 ECM
W
EA26
B
B
B−R
65 3
2IH1
21
B−W
IH2
DI−108
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
DTC P1780 Park/Neutral Position Switch Malfunction
CIRCUIT DESCRIPTION
The park/neutral position switch goes on when the shift lever is in the N o\
r P shift position. When it goes on
terminal NSW of the ECM is grounded to body ground via the starter relay, thus the terminal NSW voltage
becomes 0 V. When the shift lever is in the D, 2, L or R position, the park/neutral\
position switch goes off,
so the voltage of ECM, terminal NSW becomes battery voltage, the voltage of the ECM internal power
source. If the shift lever is moved from the N position to the D position, this signal is used for air\
−fuel ratio
correction and for idle speed control (estimated control), etc.
DTC No.DTC Detecting ConditionTrouble Area
P1780
2 or more switches are ON simultaneously for ”N”, ”2” and ”\
L”
position (2 trip detection logic)
 Short in park/neutral position switch circuit
 Park/neutral position switch
 ECMWhen driving under conditions (a) and (b) for 30 sec. or more
the park/neutral position switch is ON (N position):
(2 trip detection logic)
(a) Vehicle speed: 70 km/h (44 mph) or more
(b) Engine speed: 1,500 − 2,500 rpm
HINT:
After confirming DTC P1780 use the T OYOTA hand−held tester to confirm the PNP switch signal from ”CUR-
RENT DATA”.
WIRING DIAGRAM
DI5PV−02
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S00816
BatteryFusible
Link
F8F7
11
W−R
3EA2
W−R11 6
IG Switch B−R
Fuse BlockIGN B−L
22
22 2
2
EFI Main Relay
1
2
3 4
EFI R
−Y
EC
EB
B−R
1EB1
R
Y−R
Y−REA2IH1
22 7
BR−B E4
E7 E7 E7
IGSW
MRLY
+B
E1 B+
ECM
1
3
12
24FL AM2
FL MAIN
W R
R/B No.2 Y
DI−11 0
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
ECM Power Source Circuit
CIRCUIT DESCRIPTION
When the ignition switch is turned ON, battery positive voltage is applied t\
o the coil, closing the contacts of
the EFI main relay (Marking: EFI) and supplying power to the terminals +B\
of the ECM.
WIRING DIAGRAM
DI5PX−02
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Version 1.11 - 03/16/2010

P24681
DI−11 2
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
4 Check IGN fuse from fuse block.
NG Check for short in all the harness and
components connected to IGN fuse.
OK
5 Check ignition switch.
PREPARATION:
(a) Remove instrument lower finish panel.
(b) Remove instrument cluster finish center panel No.2.
CHECK:
Check continuity between terminals.
OK:
Shift PositionTerminal No. to continuityTerminal No. to continuity
LOCK−−
ACC3 − 4−
ON2 − 3 − 46 − 11
START1 − 2 − 45 − 6 − 11
NG Replace ignition switch.
OK
Check for open and short in harness and
connector between battery and ignition
switch and ECM.
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DI−11 4
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
9 Check for open and short in harness and connector between terminal MREL of
ECM connector and body ground (See page IN−28).
NG Repair or replace harness or connector.
OK
Check for open and short in harness and
connector between terminal +B of ECM
connector and battery (See page IN−28 ).
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P22480
BatteryStarter
FL MAIN
FL AM2EFI
EFI Main Relay
IG Switch IG
ST
Park/Neutral
Position SwitchCircuit Opening
Relay
Fuel Pump Relay
Fuel Pump
From Crankshaft Position
Sensor Fuel Pump
Resistor
(STA Signal)
(NE Signal) MRLY
FC
STA
NE
Tr1
Tr2
ECM
IGN FPR
−
DIAGNOSTICS ENGINE
DI−11 5
1996 LAND CRUISER (RM451U)
Fuel Pump Control Circuit
CIRCUIT DESCRIPTION
In the diagram below, when the engine is cranked, current flows form terminal ST of the igni\
tion switch to
terminal STA of ECM (STA signal).
When the STA signal and NE signal are input to the ECM, Tr1 is turned ON, current flows to coil of the circuit
opening relay, the relay switches on, power is supplied to the fuel pump and the fuel\
pump operates.
While the NE signal is generated (engine running), the ECM keeps Tr1 ON (circuit opening relay ON) and
the fuel pump also keeps operating.
The fuel pump speed is controlled at 2 levels (high speed or low speed) b\
y the condition of the engine (start-
ing, light load, heavy load). When the engine starts (STA ON), Tr2 in the ECM is OFF, so battery voltage is
applied directry to the fuel pump. Fuel pump operates at high speed.
After the engine starts, during idling or light loads, since Tr2 goes ON, power is supplied to the fuel pump
via the fuel pump resistor.
Fuel pump operates at low speed.
DI5PY−02
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Brought to you by BirfMark
Version 1.11 - 03/16/2010