EC-8
POSITIVE CRANKCASE VENTILATION ........539
Inspection ............................................................ ..539
REMOVAL AND INSTALLATION ..............540
ECM ................................................................ .540
Removal and Installation ..................................... ..540
SERVICE DATA AND SPECIFICATIONS
(SDS) .............. ............................................
541
SERVICE DATA AND SPECIFICATIONS
(SDS) ............................................................... .
541
Idle Speed ........................................................... ..541
Ignition Timing .......................................................541
Calculated Load Value ..........................................541
Mass Air Flow Sensor ............................................541
VQ35DE
PRECAUTION .............. ..............................
542
PRECAUTIONS .............................................. .542
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" .............................................................. ..
542
On Board Diagnostic (OBD) System of Engine
and CVT .............................................................. ..
542
General Precautions ..............................................543
PREPARATION ..........................................546
PREPARATION .............................................. .546
Special Service Tools .......................................... ..546
Commercial Service Tools .....................................546
SYSTEM DESCRIPTION ...........................548
COMPONENT PARTS .................................... .548
ENGINE CONTROL SYSTEM .................................548
ENGINE CONTROL SYSTEM : Component Parts
Location ............................................................... ..
548
Accelerator Pedal Position Sensor ........................552
Air Fuel Ratio (A/F) Sensor 1 ................................552
ASCD Steering Switch ...........................................553
Battery Current Sensor (With Battery Tempera-
ture Sensor) ......................................................... ..
553
Camshaft Position Sensor (PHASE) .....................554
Cooling Fan ......................................................... ..554
Crankshaft Position Sensor (POS) ........................554
ECM .......................................................................555
Electric Throttle Control Actuator ......................... ..555
Electronic Controlled Engine Mount .................... ..556
Engine Coolant Temperature Sensor ....................556
Engine Oil Pressure Sensor ................................ ..557
Engine Oil Temperature Sensor ............................557
EVAP Canister ..................................... ..................557
EVAP Canister Purge Volu me Control Solenoid
Valve .................................................................... ..
557
EVAP Canister Vent Control Valve ........................558
EVAP Control System Pressu re Sensor ................558
Fuel Injector ......................................................... .558
Fuel Level Sensor Unit and Fuel Pump (With Fuel
Tank Temperature Sensor) .................................. .
558
Heated Oxygen Sensor 2 ......................................559
Ignition Coil (With Power Transistor) ....................560
Intake Valve Timing Control Solenoid Valve .........560
Knock Sensor ....................................................... .560
Malfunction Indicator lamp (MIL) ...........................560
Mass Air Flow Sensor (With Intake Air Tempera-
ture Sensor) ......................................................... .
560
Oil Pressure Warning Lamp ..................................561
Power Valve Actuator 1 and 2 ..............................561
Refrigerant Pressure Sensor ................................562
Stop Lamp Switch & Brak e Pedal Position Switch .562
VIAS Control Solenoid Valve 1 and 2 .................. .562
STRUCTURE AND OPERATION .....................563
Positive Crankcase Ventilation (PCV) ...................563
On Board Refueling Vapor Recovery (ORVR) ..... .564
SYSTEM ...........................................................565
ENGINE CONTROL SYSTEM ................................ .565
ENGINE CONTROL SYSTEM : System Descrip-
tion ....................................................................... .
565
ENGINE CONTROL SYSTEM : Fail-safe .............566
MULTIPORT FUEL INJECTION SYSTEM ............. .568
MULTIPORT FUEL INJECTION SYSTEM : Sys-
tem Description .................................................... .
568
ELECTRIC IGNITION SYSTEM ............................. .571
ELECTRIC IGNITION SYSTEM : System De-
scription ................................................................ .
571
AIR CONDITIONING CUT CONTROL ................... .572
AIR CONDITIONING CUT CONTROL : System
Description ........................................................... .
573
AUTOMATIC SPEED CONTROL DEVICE (ASCD) .574
AUTOMATIC SPEED CONTROL DEVICE (AS-
CD) : System Description ..................................... .
574
COOLING FAN CONTROL .................................... .575
COOLING FAN CONTROL : System Description .575
ELECTRONIC CONTROLLED ENGINE MOUNT .. .577
ELECTRONIC CONTROLLED ENGINE MOUNT
: System Description ............................................ .
577
EVAPORATIVE EMISSION SYSTEM .....................579
EVAPORATIVE EMISSION SYSTEM : System
Description ........................................................... .
580
THROTTLE CONTROL ...........................................581
THROTTLE CONTROL : Syst em Description ......581
INTAKE VALVE TIMING CONTROL ..................... .582
INTAKE VALVE TIMING CONTROL : System De-
scription ................................................................ .
583
ENGINE PROTECTION CONTROL AT LOW EN-
GINE OIL PRESSURE ........................................... .
583
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EC-20
< PREPARATION >[QR25DE]
PREPARATION
Socket wrench Removes and installs engine coolant temperature
sensor
Oxygen sensor thread
cleaner
i.e.: (J-43897-18)
(J-43897-12) Reconditions the exhaust system threads before
installing a new oxygen sensor. Use with anti-
seize lubricant shown below.
a: 18 mm diameter with pitch 1.5 mm for Zirco-
nia Oxygen Sensor
b: 12 mm diameter with pitch 1.25 mm for Tita-
nia Oxygen Sensor
Anti-seize lubricant
i.e.: (Permatex
TM
133AR or equivalent
meeting MIL specifica-
tion MIL-A-907) Lubricates oxygen sensor thread cleaning tool
when reconditioning exhaust system threads.
Tool name
(TechMate No.) Description
S-NT705
AEM488
S-NT779
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COMPONENT PARTSEC-23
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EXHAUST COMPARTMENT
BODY COMPARTMENT
Intake valve timing intermediate lock control solenoid valve
EC-30, "Intake Valve Timing Intermediate Lock Control So-lenoid Valve"
Intake valve timing control solenoid valve
EC-30, "Intake Valve Timing Control Solenoid Valve"
Exhaust valve timing control solenoid valveEC-31, "Exhaust Valve Timing Control Solenoid Valve"
Ignition coil (with power transistor)EC-26, "Ignition Coil With Power Transistor"
Engine coolant temperature sensorEC-28, "Engine Coolant Temperature Sensor"
Intake manifold tuning valveEC-31, "Intake Manifold Tuning Valve"
Intake manifold runner control valve position sensor
EC-31, "Intake Manifold Runner Control Valve"
Intake manifold runner control valve actuator
No. Component Function
To engine assembly
JPBIA5841ZZ
No. Component Function
Air fuel ratio (A/F) sensor 1 EC-32, "Air Fuel Ratio (A/F) Sensor 1"
Heated oxygen sensor 2EC-32, "Heated Oxygen Sensor 2"
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EC-28
< SYSTEM DESCRIPTION >[QR25DE]
COMPONENT PARTS
The mass air flow sensor is placed in the stream of intake air. It
measures the intake flow rate by measuring a part of the entire
intake flow. The MAF sensor controls the temperature of the heater
in sensing element to a certain amount. The temperature distribution
around the heater changes according to the increase in intake air
volume. The change is detected by a thermistor and the air volume
data is sent to ECM by the MAF sensor.
INTAKE AIR TEMPERATURE SENSOR
The intake air temperature sensor is built-into mass air flow sensor. The sensor detects intake air temperature
and transmits a signal to the ECM.
The temperature sensing unit uses a thermistor wh ich is sensitive to the change in temperature.
*: These data are reference values on the diagnosis tool.
Manifold Absolute Pressure SensorINFOID:0000000009462062
The manifold absolute pressure (MAP) sensor is placed at intake
manifold collector. It detects intake manifold pressure and sends the
voltage signal to the ECM.
The sensor uses a silicon diaphragm which is sensitive to the
change in pressure. As the pressure increases, the voltage rises.
NOTE:
The sensor is equipped, but used for trouble diagnosis only.
Engine Coolant Te mperature SensorINFOID:0000000009462063
The engine coolant temperature sensor is used to detect the engine
coolant temperature. The sensor modifies a voltage signal from the
ECM. The modified signal returns to the ECM as the engine coolant
temperature input. The sensor uses a thermistor which is sensitive to
the change in temperature. The elec trical resistance of the ther-
mistor decreases as temperature increases.
PBIA9559J
Intake air temperature
[° C ( °F)] Vo l ta g e* (V)
25 (77) 1.9 – 2.1
80 (176) 3.2 – 3.4
JPBIA4619ZZ
JPBIA5280ZZ
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*: These data are reference values and are measured between ECM terminals.
Crankshaft Position Sensor (POS)INFOID:0000000009462064
The crankshaft position sensor (POS
) is located on the oil pan facing
the gear teeth (cogs) of the signal pl ate. It detects the fluctuation of
the engine revolution.
The sensor consists of a permanent magnet and Hall IC.
When the engine is running, the high and low parts of the teeth
cause the gap with the sensor to change.
The changing gap causes the magnet ic field near the sensor to
change.
Due to the changing magnetic fiel d, the voltage from the sensor
changes.
The ECM receives the voltage signal and detects the fluctuation of
the engine revolution.
ECM receives the signals as shown in the figure.
Camshaft Position Sensor (PHASE)INFOID:0000000009462065
The camshaft position sensor (PHASE) senses the retraction of
intake camshaft to identify a particular cylinder. The camshaft posi-
tion sensor (PHASE) senses the piston position.
When the crankshaft position sensor (POS) system becomes inoper-
ative, the camshaft position sensor (PHASE) provides various con-
trols of engine parts instead, utilizing timing of cylinder identification
signals.
The sensor consists of a permanent magnet and Hall IC.
When engine is running, the high and low parts of the teeth cause
the gap with the sensor to change.
The changing gap causes the magnet ic field near the sensor to
change.
Due to the changing magnetic field, the voltage from the sensor changes.
Engine coolant temperature
[° C ( °F)] Vo l ta g e* (V)
Resistance (k
Ω)
–10 (14) 4.4 7.0 - 11.4 20 (68) 3.5 2.37 - 2.63
50 (122) 2.2 0.68 - 1.00
90 (194) 1.0 0.236 - 0.260
SEF012P
JPBIA5848ZZ
JMBIA0714GB
JPBIA5846ZZ
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EC-32
< SYSTEM DESCRIPTION >[QR25DE]
COMPONENT PARTS
Air Fuel Ratio (A/F) Sensor 1
INFOID:0000000009462072
The sensor element of the A/F sensor 1 is composed an electrode
layer, which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the lean and rich range. Together with its
control electronics, the sensor outputs a cl ear, continuous signal throughout a wide range.
The exhaust gas components diffuse through the diffusi on layer at the sensor cell. An electrode layer is
applied voltage, and this current relati ve oxygen density in lean. Also this current relative hydrocarbon density
in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this
electrode layer of current. In additi on, a heater is integrated in the
sensor to ensure the required operating temperature of approxi-
mately 760 °C (1,400 °F).
A/F SENSOR 1 HEATER
A/F sensor 1 heater is integrated in the sensor.
The ECM performs ON/OFF duty control of the A/F sensor 1 heater corresponding to the engine operating
condition to keep the temperature of A/F s ensor 1 element within the specified range.
Heated Oxygen Sensor 2INFOID:0000000009462073
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas.
Even if switching characteristics of the air fuel ratio (A/F) sensor 1
are shifted, the air fuel ratio is controlled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1 V in richer conditions to 0 V in leaner con-
ditions.
Under normal conditions the heated ox ygen sensor 2 is not used for
engine control operation.
HEATED OXYGEN SENSOR 2 HEATER
Heated oxygen sensor 2 heater is integrated in the sensor.
The ECM performs ON/OFF control of the heated oxy gen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
JPBIA4038GB
JPBIA5446GB
SEF327R
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EC-34
< SYSTEM DESCRIPTION >[QR25DE]
COMPONENT PARTS
*: These data are reference values and are measured between ECM terminals.
Cooling FanINFOID:0000000009462077
The ECM controls the cooling fan corresponding to the
vehicle speed, engine coolant temperature, refrigerant
pressure, and air conditioner ON signal. The control system has 4-step control [HIGH/MIDDLE/LOW/OFF].
Cooling fan operates at each speed when the current flows in the cooling fan motor.
Refer to EC-59, "COOLING FAN CONTROL : System De scription (with automatic air conditioner)"
for cooling
fan operation.
EVAP CanisterINFOID:0000000009462078
EVAP canister stores the generat ed fuel vapors in the sealed fuel
tank to activated charcoals of EVAP canister when the engine is not
operating or when refueling to the fuel tank.
EVAP Canister Purge Volume Control Solenoid ValveINFOID:0000000009462079
The EVAP canister purge volume control solenoid valve uses a ON/
OFF duty to control the flow rate of fuel vapor from the EVAP canis-
ter. The EVAP canister purge volume control solenoid valve is
moved by ON/OFF pulses from the ECM. The longer the ON pulse,
the greater the amount of fuel vapor that will flow through the valve.
Engine oil temperature
[° C ( °F)] Vol tag e* (V)
Resistance (k
Ω)
–10 (14) 4.4 7.0 - 11.4 20 (68) 3.5 2.37 - 2.63
50 (122) 2.2 0.68 - 1.00
90 (194) 1.0 0.236 - 0.260
110 (230) 0.6 0.143 - 0.153
SEF012P
JPBIA5851ZZ
JMBIA0069ZZ
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MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system prov
ides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst (manifold) can then better r educe CO, HC and NOx emissions. This system uses A/F
sensor 1 in the exhaust manifold to monitor whether t he engine operation is rich or lean. The ECM adjusts the
injection pulse width according to the sensor voltage si gnal. For more information about A/F sensor 1, refer to
EC-32, "Air Fuel Ratio (A/F) Sensor 1"
. This maintains the mixture rati o within the range of stoichiometric
(ideal air-fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 is located downstream of the th ree way catalyst (manifold). Even if the switching
characteristics of A/F sensor 1 shift, the air-fuel rati o is controlled to stoichiometric by the signal from heated
oxygen sensor 2.
• Open Loop Control
The open loop system condition refers to when the EC M detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.
- Deceleration and acceleration
- High-load, high-speed operation
- Malfunction of A/F sensor 1 or its circuit
- Insufficient activation of A/F sensor 1 at low engine coolant temperature
- High engine coolant temperature
- During warm-up
- After shifting from N to D
- When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from A/F sensor 1.
This feedback signal is then sent to the ECM. The ECM cont rols the basic mixture ratio as close to the theoret-
ical mixture ratio as possible. However, the basic mi xture ratio is not necessarily controlled as originally
designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic changes dur-
ing operation (i.e., fuel injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is
then computed in terms of “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value co mpared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensati on used to maintain the mixture ratio at its theoretical
value. The signal from A/F sensor 1 indicates whether the mixture ratio is RICH or LEAN compared to the the-
oretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and an increase in
fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation ca rried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
PBIB2793E
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