1996 TOYOTA LAND CRUISER light

DI−54
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
DTC P0300 Random/Multiple Cylinder Misfire Detected
DTC P0301 Cylinder 1 Misfire Detected
DTC P0302 Cylinder 2 Misfire Detected
DTC P0303 Cylinder 3 Misfire Detected
DTC P0304 Cylinder 4 Misfire Detected
DTC P0305 Cylinder 5 Misfire Detected
DTC P0306 Cylinder 6 Misfire Detected
CIRCUIT DESCRIPTION
Misfire: The ECM uses the crankshaft position sensor and camshaft position senso\
r to monitor changes in
the crankshaft rotation for each cylinder.
The ECM counts the number of times the engine speed change rate indicates that misfire has occurred.
When the misfire rate equals or exceeds the count indicating that the engine condition has deteriorat\
ed, the
MIL lights up.
If the misfire rate is high enough and the driving conditions will cause catalyst overheating, the MIL blinks
when misfiring occurs.
DTC No.DTC Detecting ConditionTrouble Area
P0300Misfiring of random cylinders is detected during the any partic-
ular 200 or 1,000 revolutions Ignition system
 Injector
 Fuel line pressure
 EGR
 Compression pressure
 Valve clearance not to specification
 Valve timing
 Mass air flow meter
 Engine coolant temp. sensor
P0301
P0302
P0303
P0304
P0305
P0306For any particular 200 revolutions of the engine, misfiring is
detected which can cause catalyst overheating
(This causes MIL to blink)
For any particular 1,000 revolutions of the engine, misfiring is
detected which causes a deterioration in emission
(2 trip detection logic)
HINT:
When the 2 or more codes for a misfiring cylinder are recorded repeatedly bu\
t no random misfire code is
recorded, it indicates that the misfires were detected and recorded at d\
ifferent times.
DI5PF−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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P20769
(43 − 56 mph)
Vehicle Speed
70 − 90 km/h
Idling
IG SW OFF (1)(2) (3)
(4) (6)
(5)
Warm up 3 − 5 min. 2 min.
3 − 5 min.2 min.(7)
Time
DI−70
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
SYSTEM CHECK DRIVING PATTERN
(1) Connect the OBD II scan tool or TOYOTA hand −held tester to the DLC3.
(2) Start and warm up the engine with all accessories switched OFF.
(3) Run the vehicle at 70 − 90 km/h (43 − 56 mph) for 3 min. or more.
(4) Idle the engine for about 2 min.
(5) Stop at safe place and turn the ignition switch OFF.
(6) Start the engine and do steps (3) and (4) again.
(7) Check the ”READINESS TESTS” mode on the OBD II scan tool or\
TOYOTA hand−held tester.
If ”COMPL” is displayed and the MIL does not light up, the system \
is normal.
If ”INCMPL” is displayed and the MIL does not light up, run the ve\
hicle again and check it.
HINT:
”INCMPL” is displayed when either condition (a) or (b) exists.\
(a) The system check is incomplete.
(b) There is a malfunction in the system.
If there is a malfunction in the system, the MIL will light up after ste\
ps (2) to (6) above are done.
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A00560
Vehicle Speed50 − 65 km/h
Idling
IG SW OFF (1)(2) (3)
Warmed up 5 − 10 mins.
Time
(31 −
40mph)
−
DIAGNOSTICS ENGINE
DI−85
1996 LAND CRUISER (RM451U)
CONFIRMATION ENGINE RACING PATTERN
(1) Connect the OBDII scan tool or TOYOTA hand−held tester to the DLC 3.
(2) Start and warm up the engine with all accessories switched OFF.
(3) Run the vehicle at 50 − 65 km/h (31 − 40 mph) for 5 − 10 mins.
HINT:
If a malfunction exists, the MIL will light up during step (3).
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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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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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DI5K4−03
Vehicle Brought to Workshop
Customer Problem Analysis
Check DTC and Freezes Frame Data (Pre−check)
Record or Print DTC and Freezed Frame Data
DI−131
Clear DTC and Freezed Frame Data DI−131
Visual Inspection
Setting the Check Mode Diagnosis
DI−131
1
Items insideare titles of pages in this manual, with the
page number indicated in the bottom portion. See the indicated
pages for detailed explanations.
Connect an OBD II scan tool or TOYOTA hand−held tester to DLC3.
If your display shows ”UNABLE TO CONNECT TO VEHICLE” when you have connected the
scan tool/TOYOTA hand− held tester, inspect DLC3
DI−131
2
3
4
5
6
symptom does not occur
Problem Symptom Confirmation8
7Symptom Simulation
symptom occurs
DTC Check
DI−131 OK Code
11Preliminary Check
DTC ChartMechanical System Tests
Manual Shifting Test
OK
OK
Chapter 1
(Electronic) Chapter 2
(On−Vehicle)OKChapter 3
(Off
−Vehicle)OK
Matrix Chart of Problem Symptoms
− DI−147
Circuit
InspectionStop Light Signal
 O/D Cancel Signal Check
NG
Parts Inspection
NG
NG NG
Identification of ProblemRepairConfirmation TestEnd
NG
NG
12
NG13
14
15 16
17
9
10
DI−153 − DI−185
18
DI−130
DI−143
DI−131
DI−131
DI−131
DI−147 DI−147
DI−147
P.IN−18
Step 2, 3, 4, 6, 9, 15, 18:
Diagnostic steps permitting the use of the TOYOTA
hand−held tester or TOYOTA brake− out−box.
−
DIAGNOSTICS AUTOMATIC TRANSMISSION
DI−129
296
Author: Date:
1996 LAND CRUISER (RM451U)
AUTOMATIC TRANSMISSION
HOW TO PROCEED WITH TROUBLESHOOTING
Troubleshoot in accordance with the procedure on the following page.
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DI5K9−03
Q08225
Q08634
TOYOTA Hand−held Tester
DLC3
−
DIAGNOSTICS AUTOMATIC TRANSMISSION
DI−131
1996 LAND CRUISER (RM451U)
PRE−CHECK
1. DIAGNOSIS SYSTEM
(a) Description
When troubleshooting OBD II vehicles, the only dif-
ference from the usual troubleshooting procedure
is that you connect to the vehicle the OBD II scan
tool complying with SAE J1978 or TOYOTA hand −
held tester, and read off various data output from
the vehicle’s ECM.
OBD II regulations require that the vehicle’s on −
board computer lights up the Malfunction Indicator
Lamp (MIL) on the instrument panel when the com-
puter detects a malfunction in the computer itself or
in drive system components which affect vehicle
emissions. In addition to the MIL lighting up when
a malfunction is detected, the applicable DTCs pre-
scribed by SAE J2012 are recorded in the ECM
memory (See page DI−13).
If the malfunction does not occurs in 3 trips, the MIL goes off but
the DTCs remain recorded in the ECM memory.
To check the DTCs, connect an OBD II scan tool or
TOYOTA hand−held tester to the DLC3 on the ve-
hicle. The OBD II scan tool or TOYOTA hand−held
tester also enables you to erase the DTCs and
check freeze frame data and various forms of en-
gine data (For operating instructions, see the OBDII
scan tool’s instruction book).
DTCs include SAE controlled codes and Manufac-
turer controlled codes.
SAE controlled codes must be set as prescribed by
the SAE, while Manufacturer controlled codes can
be set freely by the manufacturer within the pre-
scribed limits (See page DI−143).
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