Fuel TOYOTA LAND CRUISER 1996 J80 Owner's Manual

DI−14
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
DTC No.
(See Page)
Detection ItemTrouble AreaMILMemory
P0171
( DI−51 )System too Lean
(Fuel T rim)
Air intake (hose loose)
 Fuel line pressure, leak
 Injector blockage
 Heated oxygen sensor malfunction
 Mass air flow meter
 Engine coolant temp. sensor
 *1
P0172
( DI−51 )System too Rich
(Fuel T rim)
Fuel line pressure
 Injector leak, blockage
 Heated oxygen sensor malfunction
 Mass air flow meter
 Engine coolant temp. sensor
 *1
P0300
( DI−54 )Random/Multiple Cylinder
Misfire DetectedIgnition system
 Injector
 Fuel line pressure
 EGR
 Compression pressure
 Valve clearance not to specification
 Valve timing
 Mass air flow meter
 Engine coolant temp. sensor
 *2
P0301
P0302
P0303
P0304
P0305
P0306
( DI−54 )Misfire Detected
− Cylinder 1
− Cylinder 2
− Cylinder 3
− Cylinder 4
− Cylinder 5
− Cylinder 6
P0325
( DI−59 )Knock Sensor 1 Circuit
MalfunctionOpen or short in knock sensor 1 circuit
 Knock sensor 1 (looseness)
 ECM
 *1
P0330
( DI−59 )Knock Sensor 2 Circuit
MalfunctionOpen or short in knock sensor 2 circuit
 Knock sensor 2 (looseness)
 ECM
 *1
P0335
( DI−62 )Crankshaft Position Sensor
”A” Circuit Malfunction
Open or short in crankshaft position sensor circuit for NE sig-
nal
 Crankshaft position sensor for NE signal
 Starter
 ECM
 *1
P0340
( DI−65 )Camshaft Position Sensor
Circuit MalfunctionOpen or short in camshaft position sensor circuit
 Camshaft position sensor
 ECM
 *1
P0385
( DI−67 )Crankshaft Position Sensor
”B” Circuit Malfunction
Open or short in crankshaft position sensor circuit for NE2
signal
 Crankshaft position sensor for NE2 signal
 ECM
 *1
P0401
( DI−69 )Exhaust Gas Recirculation
Flow Insufficient Detected
EGR valve stuck closed
 Short in VSV circuit for EGR
 Open in EGR gas temp. sensor circuit
 EGR hose disconnected
 ECM
 *1
P0402
( DI−80 )Exhaust Gas Recirculation
Flow Excessive Detected
EGR valve stuck open
 EGR VSV open malfunction
 Open in VSV circuit for EGR
 Short in EGR gas temp. sensor circuit
 ECM
 *1
*1: MIL lights up
*2: MIL lights up or blinking
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DI5OY−03
−
DIAGNOSTICS ENGINE
DI−19
1996 LAND CRUISER (RM451U)
PROBLEM SYMPTOMS TABLE
When the malfunction code is not confirmed in the DTC check and the problem \
still can not be confirmed
in the basic inspection, then proceed to this step and perform troubleshooting according to the numbered
order given in the table below.
SymptomSuspect AreaSee page
Engine does not crank (Does not start)1. Starting systemST−16
No initial combustion (Does not start)1. ECM power source circuit
2. Fuel pump control circuitDI−11 0
DI−11 5
No complete combustion (Does not start)1. Fuel pump control circuitDI−11 5
Engine cranks normally (Difficult to start)
1. Starter signal circuit
2. Fuel pump control circuit
3. CompressionDI−103
DI−11 5 EM−3
Cold engine (Difficult to start)1. Starter signal circuit
2. Fuel pump control circuitDI−103DI−11 5
Hot engine (Difficult to start)
1. Starter signal circuit
2. Fuel pressure control circuit
3. Fuel pump control circuitDI−103
DI−125DI−11 5
High engine idle speed (Poor idling)1. A/C signal circuit
2. ECM power source circuitAC−5
DI−11 0
Low engine idle speed (Poor idling)1. A/C signal circuit
2. Fuel pump control circuitAC−5
DI−11 5
Rough idling (Poor idling)1. Compression
2. Fuel pump control circuitEM−3
DI−11 5
Hunting (Poor idling)1. ECM power source circuit
2. Fuel pump control circuitDI−11 0
DI−11 5
Hesitation/Poor acceleration (Poor driveability)1. Fuel pump control circuit
2. A/T faultyDI−11 5
DI−147
Surging (Poor driveability)1. Fuel pump control circuitDI−11 5
Soon after starting (Engine stall)1. Fuel pump control circuitDI−11 5
During A/C operation (Engine stall)1. A/C signal circuit
2. Engine control module (ECM)AC−5
IN−18
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FI4741
(fig.1)Acceptable
Resistance kΩ
− 20 0 20 40 60 80 100
( − 4) 32 68 104 140 176 212
30
20
10
53
2
1
0.5
0.3
0.2
0.1
Temp. °C (F °)
DI−26
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
DTC P0110 Intake Air Temp. Circuit Malfunction
CIRCUIT DESCRIPTION
The intake air temperature sensor is built into the air flow meter
and senses the intake air temperature.
A thermistor built in the sensor changes the resistance value
according to the intake air temperature. The lower the intake air
temperature, the greater the thermistor resistance value, and
the higher the intake air temperature, the lower the thermistor
resistance value (See fig.1).
The intake air temperature sensor is connected to the ECM
(See next page). The 5 V power source voltage in the ECM is
applied to the intake air temperature sensor from the terminal
THA via a resistor R.
That is, the resistor R and the intake air temperature sensor are
connected in series. When the resistance value of the intake air
temperature sensor changes in accordance with changes in the
intake air temperature, the potential at terminal THA also
changes. Based on this signal, the ECM increases the fuel in-
jection volume to improve driveability during cold engine opera-
tion.
If the ECM detects the DTC ”P0110”, it operates the fail safe
function in which the intake air temperature is assumed to be
20 °C (68 °F).
Intake Air Temp.
° C (° F)Resistance
(kΩ)Voltage
(V)
−20 (− 4)16.24.3
0 (32)5.93.4
20 (68)2.52.4
40 (104)1.11.4
60 (140)0.60.9
80 (176)0.30.5
100 (212)0.10.2
DTC No.DTC Detecting ConditionTrouble Area
P0110Open or short in intake air temp. sensor circuit
Open or short in intake air temp. sensor circuit
 Intake air temp. sensor
 ECM
HINT:
After confirming DTC P110 use the OBD II scan tool or TOYOTA hand −held tester to confirm the intake air
temp. from ”CURRENT DATA”.
Temp. DisplayedMalfunction
− 40° C (− 40°F)Open circuit
140°C (284°F) or moreShort circuit
DI5P1−02
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FI6571
Throttle Position
SensorVCCVTA
IDLE2 ECM
5V
B+
−
DIAGNOSTICS ENGINE
DI−35
1996 LAND CRUISER (RM451U)
DTC P0120 Throttle/Pedal Position Sensor/Switch ”A”
Circuit Malfunction
CIRCUIT DESCRIPTION
The throttle position sensor is mounted in the throttle body and
detects the throttle valve opening angle.
When the throttle valve is fully closed, the IDL contacts in the
throttle position sensor are on, so the voltage at the terminal IDL
of the ECM becomes 0 V. At this time, a voltage of approximate-
ly 0.3 − 0.8 V is applied to terminal VTA of the ECM. When the
throttle valve is opened, the IDL contacts go off and thus the
power source voltage of approximately 12 V in the ECM is ap-
plied to the terminal IDL of the ECM. The voltage applied to the
terminal VTA of the ECM increases in proportion to the opening
angle of the throttle valve and becomes approximately 3.2 − 4.9
V when the throttle valve is fully opened. The ECM judges the
vehicle driving conditions from these signals input from termi-
nals VTA and IDL, and uses them as one of the conditions for
deciding the air− fuel ratio correction, power increase correction
and fuel −cut control etc.
DTC No.DTC Detecting ConditionTrouble Area
P0120
Condition (a) or (b) continues
(a) VTA < 0.1 V, and closed throttle position switch is OFF
(b) VTA > 4.9 VOpen or short in throttle position sensor circuit
 Throttle position sensor
 ECM
HINT:
If there is open circuit in IDL line, DTC P0120 does not indicate.
After confirming DTC P0120 use the OBD II scan tool or TOYOTA hand−held tester to confirm the
throttle valve opening percentage and closed throttle position switch condition\
.
Throttle valve opening position
expressed as percentage
Trouble Area
Throttle valve fully closedThrottle valve fully open
0 %0 %VCC line open
VTA line open or short
Approx. 99 %Approx. 100 %E2 line open
DI5P7−02
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P21242 FI7210A00027
Atmosphere
Flange
Platinum Electrode
Solid Electrolyte
(Zirconia Element)
Platinum Electrode
Heater
Coating (Ceramic)
Exhaust GasCover Ideal Air−
Fuel Mixture
Output Voltage
Richer − Air Fuel Ratio − Leaner
DI−40
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
DTC P0125 Insufficient Coolant Temp. for Closed Loop
Fuel Control
CIRCUIT DESCRIPTION
To obtain a high purification rate for the CO, HC and NOx components of th\
e exhaust gas, a three −way cata-
lytic converter is used, but for the most efficient use of the three −way catalytic converter, the air−fuel ratio
must be precisely controlled so that it is always close to the stoichiom\
etric air −fuel ratio.
The oxygen sensor has the characteristic where by its output voltage change\
s suddenly in the vicinity of the
stoichiometric air −fuel ratio. This characteristic is used to detect the oxygen concentrati\
on in the exhaust
gas and provide feedback to the computer for control of the air −fuel ratio.
When the air −fuel ratio becomes LEAN, the oxygen concentration in the exhaust increas\
es and the oxygen
sensor informs the ECM of the LEAN condition (small electromotive force: 0 V)\
.
When the air −fuel ratio is RICHER than the stoichiometric air −fuel ratio the oxygen concentration in the ex-
haust gas in reduced and the oxygen sensor informs the ECM of the RICH condit\
ion (large electromotive
force: 1 V). The ECM judges by the electromotive force from the oxygen \
sensor whether the air −fuel ratio
is RICH or LEAN and controls the injection time accordingly. However, if malfunction of the oxygen sensor
causes output of abnormal electromotive force, the ECM is unable to perform acc\
urate air −fuel ratio control.
The heated oxygen sensors include a heater which heats the zirconia element\
. The heater is controlled by
the ECM. When the intake air volume is low (the temp. of the exhaust gas i\
s low) current flows to the heater
to heat the sensor for accurate oxygen concentration detection.
DTC No.DTC Detecting ConditionTrouble Area
P0125
After the engine is warmed up, heated oxygen sensor (bank 1
sensor 2) output does not indicate RICH even once when
conditions (a), (b) and (c) continue for at least 1.5 min.
(a) Engine speed: 1,500 rpm or more
(b) Vehicle speed: 40 − 100 km/h (25 − 62 mph)
(c) Closed throttle position switch: OFF
 Open or short in heated oxygen sensor (bank 1 sensor 1)
circuit
 Heated oxygen sensor (bank1 sensor 1)
DI5P9−02
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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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DI−44
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
INSPECTION PROCEDURE
1 Check for open and short in harness and connector between ECM and heated
oxygen sensor (bank 1 sensor 1) (See page IN−28 ).
NG Repair or replace harness or connector
(See page IN−28 ).
OK
2 Check for heated oxygen sensor (bank 1 sensor 1) data.
PREPARATION:
(a) Remove the fuse cover on the instrument panel.
(b) Connect the OBD II scan tool or TOYOTA hand−held tester to the DLC3.
(c) Warm up engine to normal operating temp.
CHECK:
Read the heated oxygen sensor (bank 1 sensor 1) output voltage and sho\
rt −term fuel trim.
RESULT:
PatternHeated o xygen sensor (bank 1 sensor 1) output voltageShort−term fuel trim
1Lean condition (Changes at 0.55 V or less)Changes at about +20 %
2Rich condition (Changes at 0.4 V or more)Changes at about −20 %
3Except 1 and 2
1, 2 Check fuel trim system (See page DI−51 ).
3
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DI−46
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
DTC P0133 Heated Oxygen Sensor Circuit Slow Response (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
P0133
Response time for the heated oxygen sensor’s voltage output
to change from rich to lean, or from lean to rich, is 1 sec. or
more during idling after the engine is warmed up
(2 trip detection logic)
Heated oxygen sensor (bank 1 sensor 1)
HINT:
Sensor 1 refers to the sensor closer to the engine body.
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P0133) being output?
YES Go to relevant DTC chart.
NO
Replace heated oxygen sensor
(bank 1 sensor 1).
DI5PB−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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