Engine control TOYOTA LAND CRUISER 1996 J80 Service Manual

A00184
STARTIGT
(+)(−)
BE6653
P24674
FI6605
IGT signal waveform
5 m sec/Division (Idling)
IGT
IGF
2 V/Div.
0V 0V
−
DIAGNOSTICS ENGINE
DI−99
1996 LAND CRUISER (RM451U)
4 Check for open and short in harness and connector in IGT signal circuit betwe\
en
ECM and igniter (See page IN−28).
NG Repair or replace harness or connector.
OK
5 Check voltage between terminals IGT of ECM connector and body ground.
PREPARATION:
Remove instrument panel speaker No.1 panel (See page
SF−65 ).
CHECK:
Measure voltage between terminal IGT of ECM connector and
body ground when engine is cranked.
OK:
Voltage: More than 0.1 V and less than 4.5 V
Reference: INSPECTION USING OSCILLOSCOPE
During cranking or idling, check waveforms between terminals
IGT and E1 of engine control module.
HINT:
The correct regulator waveforms are as shown.
NG Check and replace ECM (See page IN−28 ).
NG
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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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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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−
DIAGNOSTICS ENGINE
DI−107
1996 LAND CRUISER (RM451U)
DTC P1605 Knock Control CPU Malfunction
CIRCUIT DESCRIPTION
Refer to DTC P0325, P0330 (Knock Sensor 1, 2 Circuit Malfunction) on page DI−59.
DTC No.DTC Detecting ConditionTrouble Area
P1605Engine control computer malfunction (for knock control)ECM
WIRING DIAGRAM
Refer to P0325, P0330 (Knock Sensor 1, 2 Circuit Malfunction) on page DI−59.
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P1605) being output?
YES Go to relevant DTC chart.
NO
Check and replace ECM (See page IN−28 ).
DI5PU−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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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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P22216
Pressure RegulatorVSV
ECM
To Fuel Tank
(Return)
From Delivery Pipe Intake
Manifold
P22482
BRFrom BatteryR/B No.2EB
2
2
2
2
EFI Main
22Y−R
Y−R
EB11
REA27R
R−Y
EZ1
VSV for Fuel21
EZ1
Relay
EFI
12 4
3
1B B3
L−R
Pressure Control E7
E4 3
21 FPU
MRLY
ECM
B+
E01
−
DIAGNOSTICS ENGINE
DI−125
1996 LAND CRUISER (RM451U)
Fuel Pressure Control Circuit
CIRCUIT DESCRIPTION
The ECM turns on a VSV (V acuum Switching Valve) to draw the
air into the diaphragm chamber of the pressure regulator if it de-
tects that the temperature of the engine coolant is too high dur-
ing engine starting.
The air drawn into the chamber increases the fuel pressure to
prevent fuel vapor lock at high engine temperature in order to
help the engine start when it is warm.
Fuel pressure control ends approx. 120 sec. after the engine is
started.
WIRING DIAGRAM
DI5PZ−02
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A00197
ONON
OFF
BE6653
P22965
P22966
G
E
G E Air Filter
Air Filter
DI−126
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
INSPECTION PROCEDURE
TOYOTA hand −held tester
1 Connect the TOYOTA hand−held tester and check operation of VSV for fuel
pressure control.
PREPARATION:
(a) Remove the fuse cover on the instrument panel.
(b) Connect the TOYOTA hand−held tester to the DLC3.
(c) Turn ignition switch ON and TOYOTA hand −held tester
main switch ON.
(d) Select the ACTIVE TEST mode on the TOYOTA hand −
held tester.
CHECK:
Check operation of VSV when VSV is operated by the T OYOTA
hand −held tester.
OK:
VSV is ON:
Air from pipe E is flowing out through the air filter.
VSV is OFF:
Air from pipe E is flowing out through pipe G.
OK Check and repair fuel pressure regulator (See page SF−19 ).
NG
2 Check VSV for fuel pressure control (See page SF−59).
NG Replace VSV for fuel pressure control.
OK
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A00198
ONFPU
(+)
(−)
BE6653
P24688
−
DIAGNOSTICS ENGINE
DI−127
1996 LAND CRUISER (RM451U)
3 Check for open and short in harness and connector between EFI main relay
(Marking: EFI) and ECM (See page IN−28).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN−28 ).
OBD II scan tool (excluding TOYOTA hand −held tester)
1 Check VSV for fuel pressure control (See page SF−59 ).
NG Replace VSV for fuel pressure control.
OK
2 Check voltage between terminal FPU 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 terminal FPU of ECM connector and
body ground.
OK:
Voltage: 9 − 14 V
NG Check for open and short in harness and con- nector between EFI main relay (Marking: EFI)
and ECM (See page IN−28 ).
OK
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DI−136
−
DIAGNOSTICS AUTOMATIC TRANSMISSION
1996 LAND CRUISER (RM451U)
If the lock−up is defective:
Lock−up solenoid is stuck.
Lock−up control valve is stuck.
Lock−up signal value is stuck.
(2) In the same way, check the shock and slip at the 1 → 2, 2 →3 and 3 → O/D up−shift.
Evaluation:
If the shock is excessive:
Line pressure is too high.
Accumulator is defective.
Check ball is defective. (3) Run at the D position lock −up or O/D gear and check for abnormal noise and vibration.
HINT:
The check for the cause of abnormal noises and vibration must be made with \
extreme care as it could also
be due to loss of balance in the propeller shaft, differential, torque converter clutch, etc.
(4) While running in the D position, 2nd, 3rd and O/D gears, check to see that the\
possible kick −down
vehicle speed limits for 2 →1, 3 → 2 and O/D →3 kick−downs conform to those indicated on
the automatic shift schedule.
(5) Check for abnormal shock and slip at kick −down.
(6) Check for the lock −up mechanism.
Drive in D position, O/D gear, at a steady speed (lock −up ON) of about 95 km/h (59 mph).
Lightly depress the accelerator pedal and check that the engine RPM does not change
abruptly.
If there is a big jump in engine RPM, there is no lock −up.
(b) 2 position test. Shift into the 2 position and, while driving with the accelerator pedal held \
constantly at the full throttle
valve opening position, push in one of the pattern selectors and check the fo\
llowing points:
HINT:
When the 2nd start switch is on, there is no 1 → 2 up−shift and 2 →1 down−shift.
(1) Check to see that the 1 → 2 up− shift takes place and that the shift point conforms to the automatic
shift schedule.
HINT:
There is no O/D up−shift and lock−up in the 2 position. (2) While running in the 2 position and 2nd ge ar, release the accelerator pedal and check the engine
braking effect.
Evaluation:
If there is no engine braking effect:
2nd coast brake is defective. (3) Check for abnormal noise at acceleration and deceleration, and for shock at up −shift and down −
shift.
(c) L position test. (1) While running in the L position, check to see that there is no up −shift to 2nd gear.
(2) While running in the L position, release the accelerator pedal and check the engine braking ef- fect.
Evaluation:
If there is no engine braking effect:
1stand reverse brake is defective. (3) Check for abnormal noise during acceleration and deceleration.
(d) R position test. Shift into the R position and fully depress the accelerator pedal and ch\
eck for slipping.
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