1998 TOYOTA LAND CRUISER engine air intake

CO0IQ-06
A09750
P/S Air HoseRadiator
Reservoir Tank
Intake Air
Connector
Radiator Assembly
EVAP HoseV-Bank Cover
Engine Under Cover No.1
N´m (kgf´cm, ft´lbf) : Specified torque Generator
Drive Belt
A/C CompressorA/C Compressor
Connector
A/T Oil Cooler Hose
Fan with
Fluid Coupling
Fan Pulley
49 (500, 36)
5.0 (50, 43 in.´lbf)
18 (185, 13)
Air Hose
x 8Fan Shroud Fuel Return
Hose
20 (200, 15)
A/T Oil Cooler
Hose
A/C Discharge
Tube
Clamp
Bracket WireClamp
Clamp
Lower Radiator Hose
Bracket
- COOLINGWATER PUMP
CO-3
1764 Author
: Date
:
2004 LAND CRUISER (RM1071U)
WATER PUMP
COMPONENTS

- DIAGNOSTICSAUTOMATIC TRANSMISSION
DI-403
596 Author
: Date
:
2004 LAND CRUISER (RM1071U)
P0850:
Related DTCsP0850Park/neutral position switch/Verify switch cycling
Rid /C tMainPark/neutral position switchRequired sensors/ComponentsSubCrankshaft position sensor (NE), MAF meter
Frequency of operationContinuous
Duration30 sec.
MIL operation2 driving cycles
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
P0705:
ItSpecificationItemMinimumMaximum
The monitor will run whenever the follow-
ing DTCs are not present.See page DI-361
Ignition switchON
Battery voltage10.5 V or more
P0850:
ItSpecificationItemMinimumMaximum
The monitor will run whenever the follow-
ing DTCs are not present.See page DI-361
Vehicle speed70 km/h (43 mph) or more-
Engine speed1,500 rpm or more2,500 rpm or less
Intake air amount per revolution0.9 g/rev. or more-

- DIAGNOSTICSAUTOMATIC TRANSMISSION
DI-415
608 Author
: Date
:
2004 LAND CRUISER (RM1071U)
DTC P0711 Transmission Fluid Temperature Sensor ºAº
Performance
CIRCUIT DESCRIPTION
The ATF temperature sensor converts fluid temperature into a resistance value which is input into the ECM.
DTC No.DTC Detecting ConditionTrouble Area
P0711
(A) Both (a) and (b) are detected: (2-trip detection logic)
(a) Intake air and engine coolant temps. are more than -10°C
(14°F) at engine start
(b) After normal driving for over 20 min. and 9 km (6 mile) or
more, ATF temp. is less than 20°C (68°F)
(B) After 17 min. of engine start, the ATF temp. is 110°C
(230°F) or more (2-trip detection logic).

Open or short in ATF temperature sensor No. 1 circuit

ATF temperature sensor No. 1

ECM
MONITOR DESCRIPTION
The ATF temperature sensor converts the ATF temperature to an electrical resistance value. Based on the
resistance, the ECM determines the ATF temperature and detects an opens or shorts in the ATF temperature
circuit or a fault of the ATF temperature sensor.
After running the vehicle for a certain period, the ATF temperature should increase. If the ATF temperature
is below 10C (50F) after running the vehicle for a certain period, the ECM interprets this as a fault, and
turns on the MIL.
When the ATF temperature is 110C (230F) or more after 17 minutes of engine cold start, the ECM also
determines this as a fault, turns on the MIL, and stores the DTC.
MONITOR STRATEGY
Related DTCsP0711ATF temperature sensor/Rationality check
Required sensors/ComponentsATF temperature sensor
Frequency of operationContinuous
Duration3 sec.
MIL operation2 driving cycles
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever the follow-
ing DTCs are not present.See page DI-361
ATF Temperature sensor ºAº circuit
ECT (Engine coolant temperature) sensor
circuitThere is no malfunction in the circuit shown on the left.
IAT (Intake air temperature) sensor circuit
Time after engine start18 min. and 20 sec. or more-
ECT-15°C (5°F) or more-
Driving distance after engine start9 km (6 mile) or more-
IAT (12 sec. after engine start)-20°C (-4°F) or more-
ECT (12 sec. after engine start)-20°C (-4°F) or more-
DIC30-01

- DIAGNOSTICSAUTOMATIC TRANSMISSION
DI-367
560 Author
: Date
:
6. DEFINITION OF TERMS
TermDefinition
Monitor descriptionDescription of what the ECM monitors and how it detects malfunctions (monitoring purpose and its details).
Related DTCsDiagnostic code
Typical enabling condition
Preconditions that allow the ECM to detect malfunctions.
With all preconditions satisfied, the ECM sets the DTC when the monitored value(s) exceeds the malfunction
threshold(s).
Sequence of operation
The priority order that is applied to monitoring, if multiple sensors and components are used to detect the malfunc-
tion.
While another sensor is being monitored, the next sensor or component will not be monitored until the previous
monitoring has concluded.
Required sensor/compo-
nentsThe sensors and components that are used by the ECM to detect malfunctions.
Frequency of operation
The number of times that the ECM checks for malfunctions per driving cycle.
ºOnce per driving cycleº means that the ECM detects malfunction only one time during a single driving cycle.
ºContinuousº means that the ECM detects malfunction every time when enabling condition is met.
DurationThe minimum time that the ECM must sense a continuous deviation in the monitored value(s) before setting a
DTC. This timing begins after the ºtypical enabling conditionsº are met.
Malfunction thresholdsBeyond this value, the ECM will conclude that there is a malfunction and set a DTC.
MIL operation
MIL illumination timing after a defect is detected.
ºImmediatelyº means that the ECM illuminates MIL the instant the ECM determines that there is a malfunction.
º2 driving cycleº means that the ECM illuminates MIL if the same malfunction is detected again in the 2nd driving
cycle.
7. TOYOTA/LEXUS PART AND SYSTEM NAME LIST
This reference list indicates the part names used in this manual along with their definitions.
TOYOTA/LEXUS nameDefinition
Toyota HCAC system, Hydrocarbon adsorptive Catalyst
(HCAC) system, HC adsorptive three-way catalystHC adsorptive three-way catalytic converter
Variable Valve Timing sensor, VVT sensorCamshaft position sensor
Variable valve timing system, VVT systemCamshaft timing control system
Camshaft timing oil control valve, Oil control valve OCV,
VVT, VSVCamshaft timing oil control valve
Variable timing and lift, VVTLCamshaft timing and lift control
Crankshaft position sensor ºAºCrankshaft position sensor
Engine speed sensorCrankshaft position sensor
THAIntake air temperature
Knock control moduleEngine knock control module
Knock sensorEngine knock sensor
Mass or volume air flow circuitMass air flow sensor circuit
Vacuum sensorManifold air pressure sensor
Internal control module, Control module, Engine control
ECU, PCMPower train control module
FC idleDeceleration fuel cut
Idle air control valveIdle speed control
VSV for CCV, Canister close valve VSV for canister controlEvaporative emissions canister vent valve
VSV for EVAP, Vacuum switching valve assembly No. 1,
EVAP VAV, Purge VSVEvaporative emissions canister purge valve
VSV for pressure switching valve, Bypass VSVEvaporative emission pressure switching valve
Vapor pressure sensor, EVAP pressure sensor, Evaporative
emission control system pressure sensorFuel tank pressure sensor
Charcoal canisterEvaporative emissions canister
ORVR systemOn-boad refueling vapor recovery system
Intake manifold runner controlIntake manifold tuning system
Intake manifold runner valve, IMRV, IACV (runner valve)Intake manifold tuning valve
Intake control VSVIntake manifold tuning solenoid valve

P20302
FI7210
A00798
Atmosphere
Housing
Platinum Electrode
Solid Electrolyte
(Zirconia Element)
Platinum Electrode
Heater
Coating (Ceramic)
Exhaust Gas CoverIdeal Air-Fuel Mixture
Output Voltage
Richer - Air Fuel Ratio - Leaner
A21040
Reference(Bank 1 Sensor 1 System Drawing) :
ECM
EFI or ECD Relay
EFI or ECD
Fuse No. 1 From
Battery
GroundOX1A
MREL HT1A
Duty
Control Heater
Sensor Heated Oxygen Sensor
EFI or ECD
Fuse No. 2
E2 DI-50
- DIAGNOSTICSENGINE
243 Author
: Date
:
CIRCUIT DESCRIPTION
To obtain a high purification rate for the CO, HC and NOx components of the 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 stoichiometric air-fuel ratio.
The heated oxygen sensor has the characteristic which its output voltage changes suddenly in the vicinity
of the stoichiometric air-fuel ratio. This characteristic is used to detect the oxygen concentration in the ex-
haust gas and provide the ECM with feedback to control the air-fuel ratio.
When the air-fuel ratio becomes LEAN, the oxygen concentration in the exhaust increases and the heated
oxygen sensor informs the ECM of the LEAN condition (low voltage, i.e. less than 0.45 V).
When the air-fuel ratio is RICHER than the stoichiometric air-fuel ratio, the oxygen concentration in the ex-
haust gas is reduced and the heated oxygen sensor informs the ECM of the RICH condition (high voltage,
i.e. more than 0.45 V). The ECM judges by the voltage output from the heated oxygen sensor whether the
air-fuel ratio is RICH or LEAN and controls the injection time accordingly. However, if malfunction of the
heated oxygen sensor causes output of abnormal voltage, this disables the ECM for performing an accurate
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 temperature of the exhaust gas is
low) current flows to the heater to heat the sensor for accurate oxygen concentration detection.
HINT:
The ECM provides a pulse width modulated control circuit to adjust current through the heater. The heated
oxygen sensor heater circuit uses a relay on the B+ side of the circuit.

FI6929A09074A09707
Power Transistor
Output
Voltage
AB B+
Temperature Sensor
Platinum Hot Wire
Temperature Sensor
Platinum Hot Wire
- DIAGNOSTICSENGINE
DI-57
250 Author
: Date
:
2004 LAND CRUISER (RM1071U)
DTC P0100 Mass or Volume Air Flow Circuit
DTC P0102 Mass or Volume Air Flow Circuit Low Input
DTC P0103 Mass or Volume Air Flow Circuit High Input
CIRCUIT DESCRIPTION
The Mass Air Flow (MAF) meter measures the amount of air flowing through the throttle valve. The ECM uses
this information to determine the fuel injection time and provide a proper air fuel ratio. Inside the MAF meter,
there is a heated platinum wire exposed to the flow of intake air.
By applying a specific current to the wire, the ECM heats this wire to a given temperature. The flow of incom-
ing air cools the wire and an internal thermistor, affecting their resistance. To maintain a constant current
value, the ECM varies the voltage applied to these components in the MAF meter. The voltage level is pro-
portional to the airflow through the sensor. The ECM interprets this voltage as the intake air amount.
The circuit is constructed so that the platinum hot wire and temperature sensor provide a bridge circuit, with
the power transistor controlled so that the potential of A and B remains equal to maintain the set temperature.
DTC No.DTC Detection ConditionTrouble Area
P0100Open or short in mass air flow meter circuit for more than 3
sec.
P0102Open or short in mass air flow meter circuit for more than 3
sec.
Open or short in mass air flow meter circuit

Mass air flow meter
P0103
Open in mass air flow meter circuit for more than 3 sec. (EVG
circuit)
Short in mass air flow meter circuit for more than 3 sec. (+B
circuit)
Mass air flow meter

ECM
DIC23-01

- DIAGNOSTICSENGINE
DI-65
258 Author
: Date
:
2004 LAND CRUISER (RM1071U)
DTC P0101 Mass or Volume Air Flow Circuit Range/
Performance Problem
CIRCUIT DESCRIPTION
Refer to DTC P0100, P0102 and P0103 on page DI-57.
DTC No.DTC Detecting ConditionTrouble Area
P0101
After engine is warmed up, conditions (a), (b), (c) and (d) con-
tinue for more than 10 seconds:
(2 trip detection logic)
(a) Throttle valve fully closed
(b) Voltage output of the mass air flow meter is more than 2.2
V.
(c) Engine coolant temperature is more than 70 °C (158 °F).
(d) Engine speed is less than 900 rpm.

Mass air flow meter
Conditions (a), (b) and (c) continue for more than 6 seconds
with engine speed: (2 trip detection logic)
(a) Engine speed is more than 0 rpm.
(b) VTA is more than 0.1 V.
(c) Voltage output of the mass air flow meter is less than 0.25
V.
MONITOR DESCRIPTION
The MAF (Mass Air Flow) meter helps the ECM calculate the amount of air flowing through the throttle valve.
The ECM uses this information to determine the fuel injection time and provide a proper air fuel ratio. Inside
the MAF meter, there is a heated platinum wire exposed to the flow of intake air. By applying a specific current
to the wire, the ECM heats this wire to a given temperature. The flow of incoming air cools the wire and an
internal thermistor, affecting their resistance. To maintain a constant current value, the ECM varies the volt-
age applied to these components in the MAF meter. The voltage level is proportional to the air flow through
the MAF meter. The ECM interprets this voltage as the intake air amount. If there is a defect in the MAF meter
or an open or short circuit, the voltage level will deviate outside the normal operating range. The ECM inter-
prets this deviation as a defect in the MAF meter and sets a DTC.
Example:
If the voltage is more than 2.2 V at idle or less than 0.25 V at idle OFF, the ECM interprets this as a defect
in the MAF meter and sets a DTC.
MONITOR STRATEGY
Related DTCsP0101Mass air flow meter rationality
Main sensors/componentsMass air flow meter
Required sensors/componentsRelated sensors/componentsEngine speed sensor, Engine coolant tempera-
ture sensor, Throttle position sensor
Frequency of operationContinuous
Duration10 sec. (High voltage)
6 sec. (Low voltage)
MIL operation2 driving cycles
Sequence of operationNone
DI1LC-17

- 20 0 20 40 60 80 100
(- 4) 32 68 104 140 176 212 30
20
10
5
3
2
1
0.5
0.3
0.2
0.1
A21047
Acceptable (Fig.1)
Resistance KW
Temp. C (F)
DI-68
- DIAGNOSTICSENGINE
261 Author
: Date
:
2004 LAND CRUISER (RM1071U)
DTC P0110 Intake Air Temperature Circuit
DTC P0112 Intake Air Temperature Circuit Low Input
DTC P0113 Intake Air Temperature Circuit High Input
CIRCUIT DESCRIPTION
The intake air temperature (IAT) sensor, mounted on the mass
air flow (MAF) meter, monitors the intake air temperature. The
IAT sensor has a thermistor that varies its resistance depending
on the temperature of the intake air. When the air temperature
is low, the resistance in the thermistor increases. When the tem-
perature is high, the resistance drops. The variations in resis-
tance are reflected as voltage changes to the ECM terminal.
(See Fig. 1).
The intake air temperature sensor is connected to the ECM
(See below ). The 5 V power source voltage in the ECM is ap-
plied to the intake air temperature sensor from terminal THA
(THAR) via 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 voltage at terminal THA (THAR) also
changes. Based on this signal, the ECM increases the fuel in-
jection volume to improve the driveability during cold engine op-
eration.
DTC No.Proceed toDTC Detection ConditionTrouble Area
P0110Step 1
Open or short in intake air
temperature sensor circuit for
0.5 sec.

Open or short in intake air temperature sensor circuit
P0112Step 4Short in intake air tempera-
ture sensor circuit for 0.5 sec.

Open or short in intake air temperature sensor circuit

Intake air temperature sensor (built in mass air flow meter)

ECM
P0113Step 2Open in intake air tempera-
ture sensor circuit for 0.5 sec.
ECM
HINT:
After confirming DTC ºP0110, P0112 or P0113º, use the hand-held tester or the OBD II scan tool to confirm
the intake air temperature in the ºDIAGNOSIS / ENHANCED OBD II / DATA LIST / ALLº.
Temperature DisplayedMalfunction
-40°C (-40°F)Open circuit
140°C (284°F) or moreShort circuit
DI1LE-13