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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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 short term fuel trim value can be read using t\
he OBD
II scan tool or TOYOTA hand held 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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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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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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Q08582
ECM
O/D OFF Indicator Light
(Combination Meter)
Ignition Switch
Fuse BlockO/D Main Switch* E7
2
P−L
B−L Y
GAUGE
Battery B+
W
2
Y
3 2
4 4
2
2 2
4
W−B
6
FL AM1
B−Y
22
E6 A
A
EA2 C12
C12
19
OD2
B ID2
J1
B 9
1
1 8
3
Fuse Block
P−L
P−L
AM1
2
BF
R/B No. 2 R/B No. 2
O/D Main switch
Contact go off with switch pushed in.
Contact go on with switch once again.
*:
DI−174
−
DIAGNOSTICS AUTOMATIC TRANSMISSION
1996 LAND CRUISER (RM451U)
O/D Main Switch & O/D OFF Indicator Light Circuit
CIRCUIT DESCRIPTION
The O/D main switch contacts go off when the switch is pushed in and come on when it is pushed once again.\
In O/D main switch OFF position, the O/D OFF indicator lights up, and the \
ECM prohibits shifting to O/D.
WIRING DIAGRAM
DI5L3−03
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Q08584
ECM
Pattern Select Switch*
(PWR Mode Switch)
PWR
E7
P−B
B−W
PWR Indicator Light
(Combination Meter)
ID2
63
C12
13
16
20
15
B
J6
EGU−IG
Fuse Block
Ignition Switch
EA2
AM1
IG1
Fuse Block
AM1
P−B
P−B
6 B
B B ID2
B−W
B−W
3
1
B−Y
2
4
222
1 FL AM1
F6
Battery
2
2
3
4
WB −L
R/B No. 2
R/B No. 2
Pattern Select Switch (PWR Mode Switch)
When the PWR mode switch is pushed in, the switch is contacted and
the PWR mode is celected.
To cancel the PWR mode, push the PWR mode switch onec again.
*:
−
DIAGNOSTICS AUTOMATIC TRANSMISSION
DI−179
1996 LAND CRUISER (RM451U)
Pattern Select Switch Circuit (PWR Mode Switch)
CIRCUIT DESCRIPTION
The ECM memory contains the shift programs for the NORMAL and POWER pattern\
s, 2 position, L position
and the lock −up patterns. Following the programs corresponding to the signals from th\
e pattern select
switch, the park/neutral position switch and other various sensors, the ECM swi\
tches the solenoid valves
ON and OFF, and control the transmission gear change and the lock −up clutch operation.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check operation of PWR indicator light.
PREPARATION:
Check if the PWR indicator light normally when the PWR mode switch is set to NORM and PWR position.
NG Check and repair PWR indicator light.
OK
DI5L6−03
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Q08580
R−W
J1
A
W 5BRY
IG3
O
Ignition Switch
Fuse Block
GAUGE
Pattern Select Switch*
(2nd Start Switch)
B ECM
18
IH2 12
HI
1
113
9
E4
2C12
Battery
FL AM1
Fuse Block
B−L
W
B−Y
2
4
F6
6 A
A
Y
3
1
E4HOLD
2
EA2
AM1
22
1
AM1 IG1
B
C12
ID3 IH2
O
R−W
2 2
3
42nd STRT Indicator Light
(Combination Meter)
12
Y
R/B No. 2 R/B No. 2
Pattern Select Switch (2nd Start Switch)
When the 2nd start switch is pushed, the switch is contacted and the 2nd\
mode is selected.
To cancel the 2nd start, push the 2nd start swtch once again. The 2nd star\
t is automatically cancelled
out when the ignition switch is turned OFF.
*:
DI−182
−
DIAGNOSTICS AUTOMATIC TRANSMISSION
1996 LAND CRUISER (RM451U)
Pattern Select Switch Circuit (2nd Start Switch) & 2nd Start
Switch Indicator Light Circuit
CIRCUIT DESCRIPTION
When 2nd start mode is selected with the pattern select switch, the ECM cont\
rols the solenoid valves and
the transmission starts from 2nd gear.
In D position, the transmission automatically shifts up through 3rd to O\
/D as usual.
In 2nd position, the transmission is held in 2nd gear.
WIRING DIAGRAM
DI5L8−03
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Version 1.11 - 03/16/2010
Q08580
R-W
J1
A
W 5BRY
IG3
O
Ignition Switch
Fuse Block
GAUGE
(*) Pattern Select Switch
(2nd Start Switch)
B
ECM
18
IH2 12
HI
1
113
9
E4
2
C12
Battery
FL AM1
Fuse Block
B-L
W
B-Y
2
4
F6
6 A
A
Y
3
1
E4HOLD
2
EA2
AM1
22
1
AM1 IG1
B
C12
IG3 IL2
O
R-W
2 2
3
42nd STRT Indicator Light
(Combination Meter)
12
Y
R/B No.2 R/B No.2
DI-185
-
DIAGNOSTICS AUTOMATIC TRANSMISSION
1996 LAND CRUISER (RM451U)
Pattern Select Switch Circuit (2nd Start Switch) & 2nd Start
Switch Indicator Light Circuit
CIRCUIT DESCRIPTION
When 2nd start mode is selected with the pattern select switch, the ECM cont\
rols the solenoid valves and
the transmission starts from 2nd gear.
In D position, the transmission automatically shifts up through 3rd to O\
/D as usual.
In 2nd position, the transmission is held in 2nd gear.
WIRING DIAGRAM
(*) Pattern Select Switch (2nd Start Switch)
When the 2nd start switch is pushed, the switch is contacted and the 2nd\
mode is selected.
To cancel the 2nd start, push the 2nd start switch once again. The 2nd sta\
rt is automatically cancelled out
when the ignition switch is turned OFF.
DI5L8-02
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