1996 TOYOTA LAND CRUISER wiring

A00484
Intake Air Temp. Sensor
(Inside the mass air flow meter)
3
4 L−Y
BR−B 5V
ECM
E5
E5
THA
E1
E2
P22420
3
9 R
−
DIAGNOSTICS ENGINE
DI−27
1996 LAND CRUISER (RM451U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
If DTCs P0110 (Intake Air Temp. Circuit Malfunction), P0115 (Engine Coolant Temp. Circuit Malfunction),
P0120 (Throttle/Pedal Position Sensor/Switch ”A” Circuit Malfunction)\
are output simultaneously, E2 (Sen-
sor Ground) may be open.
1 Connect the OBD II scan tool or TOYOTA hand −held tester, and read value of
intake air temperature.
PREPARATION:
(a) Remove the fuse cover on the instrument panel.
(b) Connect the OBD II scan tool or TOYOTA hand−held tester to DLC3.
(c) Turn ignition switch ON and OBD II scan tool or TOYOTA hand−held tester main switch ON.
CHECK:
Read temp. value on the OBD II scan tool or TOYOTA hand −held tester.
OK:
Same as actual intake air temp.
HINT:
If there is open circuit, push OBD II scan tool or TOYOTA hand− held tester indicates − 40° C (− 40°F).
If there is short circuit, OBD II scan tool or TOYOTA handheld tester indicates 140° C (284°F) or more.
NG − 40° C (− 40 °F) ....Go to step 2.
140 °C (284°F) or more ....Go to step 4.
OK
Check for intermittent problems
(See page DI−3 ).
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A00485
Engine Coolant Temp. Sensor2
1 R−W
BR−B 5V
ECM
E5
E5
THW
E1
E2
4
9
P22421
DI−30
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
DTC P0115 Engine Coolant Temp. Circuit Malfunction
CIRCUIT DESCRIPTION
A thermistor built into the engine coolant temperature sensor changes the\
resistance value according to the
engine coolant temperature.
The structure of the sensor and connection to the ECM is the same as in the\
intake air temp. circuit malfunc-
tion shown on page DI−26.
If the ECM detects the DTC P0115, it operates the fail safe function in which the engine coolant temp.\
is
assumed to be 80 °C (176
°F).
DTC No.Detection ItemTrouble Area
P0115Open or short in engine coolant temp. sensor circuit
 Open or short in engine coolant temp. sensor circuit
 Engine coolant temp. sensor
 ECM
HINT:
After confirming DTC P0115 use the OBD II scan tool or TOYOTA hand −held tester to confirm the engine
coolant temp. from CURRENT DATA.
Temp. DisplayedMalfunction
− 40° C (− 40°F)Open circuit
140°C (284°F) or moreShort circuit
WIRING DIAGRAM
DI5P5−02
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A00483
2
1 3 4R−G
G−B
G−W
BR−B
Throttle Position Sensor
* Closed Throttle
Position Switch
* E5 E5
E5 E5
10 1
11 9 VTA
E2 VCC
IDL 5V
E1 B+
P22422
ECM
FI7052
DI−36
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
If DTCs P0110 (Intake Air Temp. Circuit Malfunction), P0115 (Engine Coolant Temp. Circuit Malfunction),
P0120 (Throttle/Pedal Position Sensor/Switch ”A” Circuit Malfunction)\
are output simultaneously, E2 (Sen-
sor Ground) may be open.
1 Connect the OBD II scan tool or TOYOTA hand −held tester and read the throttle
valve opening percentage.
PREPARATION:
(a) Remove the fuse cover on the instrument panel.
(b) Connect the OBD II scan tool or TOYOTA hand−held tester to DLC3.
(c) Turn ignition switch ON and push the OBD II scan tool or TOYOTA hand−held tester main switch ON.
CHECK:
Read the throttle valve opening percentage.
OK:
Throttle valveThrottle valve opening positionexpressed as percentage
Fully openApprox. 75 %
Fully closedApprox. 10 %
OK Check for intermittent problems (See page DI−3 ).
NG
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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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FI7130
Vehicle Speed50 − 65 km/h
(31 − 40 mph)
Idling
IG SW OFF 1 − 3 min.1 min. Time
(1)(2)(3) (4)
(5)
−
DIAGNOSTICS ENGINE
DI−43
1996 LAND CRUISER (RM451U)
DTC P0130 Heated Oxygen Sensor Circuit Malfunction
(Bank 1 Sensor 1)
CIRCUIT DESCRIPTION
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control) on page DI−40.
DTC No.DTC Detecting ConditionTrouble Area
P0130
Voltage output of heated oxygen sensor (bank 1 sensor 1)
remains at 0.4 V or more, or 0.55 V or less, during idling after
the engine is warmed up (2 trip detection logic)Heated oxygen sensor (bank 1 sensor 1)
 Fuel trim malfunction
HINT:
Sensor 1 refers to the sensor closer to the engine body.
The heated oxygen sensor’s output voltage and the shortterm fuel trim value can be read using t\
he OBD
II scan tool or TOYOTA handheld tester.
WIRING DIAGRAM
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control) on page DI−35 for WIRING
DIAGRAM.
CONFIRMATION DRIVING PATTERN
(1) Connect the TOYOTA hand−held tester to the DLC3.
(2) Switch the TOYOTA hand−held tester from normal mode to check mode (See page DI−3).
(3) Start the engine and warm it up withe all accessory switches OFF.
(4) Drive the vehicle at 50 − 65 km/h (31 − 40 mph) for 1 − 3 min. to warm up the heated oxygen sensor.
(5) Let the engine idle for 1 min.
HINT:
If a malfunction exists, the MIL will light up during step (5).
NOTICE:
If the conditions in this test are not strictly followed, detection of the\
malfunction will not be possible.
If you do not have a TOYOTA hand −held tester, turn the ignition switch OFF after performing steps
(3) to (5), then perform steps (3) to (5) again.
DI5PA−02
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BE6653
P24460A00950
ON
HT1HT2
(−) (+)
−
DIAGNOSTICS ENGINE
DI−47
1996 LAND CRUISER (RM451U)
DTC P0135 Heated Oxygen Sensor Heater Circuit
Malfunction (Bank 1 Sensor 1)
DTC P0141 Heated Oxygen Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
CIRCUIT DESCRIPTION
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control) on page DI−40.
DTC No.DTC Detecting ConditionTrouble Area
P0135
P0141
When the heater operates, heater current exceeds 2 A
(2 trip detection logic)Open or short in heater circuit of heated oxygen sensor
 Heated oxygen sensor heater
 ECM
Heater current of 0.25 A or less when the heater operates
(2 trip detection logic)
HINT:
Sensor 1 refers to the sensor closer to the engine body.
Sensor 2 refers to the sensor farther away from the engine body.
WIRING DIAGRAM
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control) on page DI−40 for WIRING
DIAGRAM.
INSPECTION PROCEDURE
1 Check voltage between terminals HT1, HT2 of ECM connector and body ground.
PREPARATION:
(a) Remove instrument panel speaker No.1 panel (See page SF−65 ).
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminals HT1, HT2 of ECM connec-
tor and body ground.
HINT:
Connect terminal HT1 to bank 1 sensor 1.
Connect terminal HT2 to bank 1 sensor 2.
OK:
Voltage: 9 − 14 V
OK Check and replace ECM (See page IN−28 ).
NG
DI5PC−02
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−
DIAGNOSTICS ENGINE
DI−49
1996 LAND CRUISER (RM451U)
DTC P0136 Heated Oxygen Sensor Circuit Malfunction
(Bank 1 Sensor 2)
CIRCUIT DESCRIPTION
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control) on page DI−40.
DTC No.DTC Detecting ConditionTrouble Area
P0136
Voltage output of the heated oxygen sensor (bank 1 sensor 2)
remains at 0.4 V or more or 0.5 V or less when the vehicle is
driven at 40 km/h (25 mph) or more after the engine is warmed
up. (2 trip detection logic).
Heated oxygen sensor (bank 1 sensor 2)
HINT:
Sensor 2 refers to the sensor farther away from the engine body.
WIRING DIAGRAM
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control) on page DI−40 for WIRING
DIAGRAM.
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P0136) being output?
YES Go to relevant DTC chart.
NO
2 Check for open and short in harness and connector between ECM and heated\
oxygen sensor (bank 1 sensor 2) (See page IN−28 ).
NG Repair or replace harness or connector.
OK
DI5PD−02
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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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