1996 TOYOTA LAND CRUISER ac wiring diagram

V08423
Knock Sensor 1
GR ECM
KNK E1
12
E6
WIRING DIAGRAM
Wiring Diagram
This shows a wiring diagram of the circuit.
Use this diagram together with ELECTRICAL
WIRING DIAGRAM to thoroughly understand the
circuit.
Wire colors are indicated by an alphabetical code.
B = Black, L = Blue, R = Red, BR = Brown,
LG = Light Green, V = Violet, G = Green,
O = Orange, W = White, GR = Gray, P = Pink,
Y = Yellow, SB = Sky Blue
The first letter indicates the basic wire color and
the second letter indicates the color of the stripe.
DTC P0325Knock Sensor 1 Circuit Malfunction
CIRCUIT DESCRIPTION
Knock sensor is fitted to the cylinder block to detect engine knocking. This sensor c\
ontains a piezoelectric element which
generates a voltage when it becomes deformed, which occurs when the cyli\
nder block vibrates due to knocking. If engine
knocking occurs, ignition timing is retarded to suppress it.
DTC No. DTC Detection Condition Trouble Area
P0325 No knock sensor 1 signal to ECM with engine speed,
1,200 rpm or more.  Open or short in knock sensor1 circuit
 Knock sensor 1 (looseness)
 ECM
If the ECM detects the above diagnosis conditions, it operates the fall sa\
fe function in which the corrective retard angle
value is set to the maximum value.
 Diagnostic Trouble Code No. and Detection Item
 Circuit Description
The major role and operation, etc. of the circuit
and its component parts are explained.
 Indicates the diagnostic trouble code, diagnostic
trouble code set parameter and suspect area of
the problem.

IN−26
−
INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
1996 LAND CRUISER (RM451U)
6. CIRCUIT INSPECTION
How to read and use each page is shown below.
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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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−
DIAGNOSTICS ENGINE
DI−25
1996 LAND CRUISER (RM451U)
DTC P0101 Mass Air Flow Circuit Range/Performance
Problem
CIRCUIT DESCRIPTION
Refer to DTC P0100 (Mass Air Flow Circuit Malfunction) on page DI−20.
DTC No.DTC Detecting ConditionTrouble Area
P0101
Conditions (a) and (b) continue with engine speed 900 rpm or
less (2 trip detection logic):
(a) Closed throttle position switch: ON
(b) Mass air flow meter output > 2.2 V
Mass air flow meterConditions (a) and (b) continue with engine speed 1500 rpm
(2 trip detection logic):
(a) Mass air flow meter output < 1 V
(b) VTA  0.72 V
WIRING DIAGRAM
Refer to DTC P0100 (Mass Air Flow Circuit Malfunction) on page DI−20 for the WIRING DIAGRAM.
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P0101) being output?
YES Go to relevant DTC chart.
NO
Replace mass air flow meter.
DI5P0−02
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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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