Downloaded from www.Manualslib.com manuals search engine Engine Electrical Devices: 1C-13
Mass Air Flow (MAF) and Intake Air
Temperature (IAT) Sensor Removal and
Installation
S6RW0D1306019
CAUTION!
• Do not disassemble MAF and IAT sensor.
• Do not expose MAF and IAT sensor to any
shock.
• Do not clean MAF and IAT sensor.
• If MAF and IAT sensor has been dropped, it
should be replaced.
• Do not blow compressed air by using air
gun or the like.
• Do not put finger or any other object into
MAF and IAT sensor. Malfunction may
occur.
Removal
1) Disconnect negative cable at battery.
2) Disconnect MAF and IAT sensor connector.
3) Remove air cleaner case (1).
4) Remove MAF and IAT sensor (2) from air cleaner
case.
Installation
Reverse removal procedure noting the followings.
• Tighten MAF and IAT sensor screws to specified
torque.
Tightening torque
MAF and IAT sensor screw: 1.5 N·m (0.15 kgf-m,
1.1 lb-ft)
• Connect MAF and IAT sensor connector securely.
Intake Air Temperature (IAT) Sensor InspectionS6RW0D1306020
CAUTION!
Do not heat up MAF and IAT sensor more
than 100 °C (212 °F). Otherwise, MAF and IAT
sensor will be damaged.
• Check sensor O-ring (1) for damage and
deterioration. Replace as necessary.
• Blow hot air to temperature sensing part (2) of MAF
and IAT sensor (3) using hot air drier (4) and measure
resistance between sensor terminals while heating air
gradually.
If measured resistance does not show such
characteristic as shown, replace MAF and IAT sensor.
Intake air temperature sensor resistance
–20 °C (–4 °F): 13.6 – 18.4 kΩ
20 °C (68 °F): 2.21 – 2.69 kΩ
60 °C (140 °F): 0.493 – 0.667 kΩ
I6RW0D130004-02
[A]: Lower limit [D]: Resistance
[B]: Nominal [E]: Temperature
[C]: Upper limit 5. Temperature gauge
20 0
68 32 104 140 17640 60 80 (2.45)
(0.58)
1
2 3
45
[A][B]
[E] [C] [D]
I4RS0A130012-01
Downloaded from www.Manualslib.com manuals search engine 1C-14 Engine Electrical Devices:
Specifications
Tightening Torque SpecificationsS6RW0D1307001
Reference:
For the tightening torque of fastener not specified in this section, refer to “Fasteners Information in Section 0A”. Fastening partTightening torque
Note
N⋅mkgf-mlb-ft
ECM mounting bolt 8 0.8 6.0 )
ECT sensor 15 1.5 11.0 )
Heated oxygen sensor 45 4.5 32.5 )
CMP sensor bolt (non-VVT model) 10 1.0 7.5 )
CMP sensor bolt (VVT model) 11 1.1 8.0 )
CKP sensor bolt 11 1.1 8.0 )
Knock sensor 22 2.2 16.0 )
MAF and IAT sensor screw 1.5 0.15 1.1 )
Downloaded from www.Manualslib.com manuals search engine Engine Mechanical: 1D-1
Engine
Engine Mechanical
General Description
Engine Construction DescriptionS6RW0D1401001
The engine is water-cooled, in line 4 cylinders, 4 stroke cycle gasoline unit with its DOHC (Double overhead camshaft)
valve mechanism arranged for “V” type valve configuration and 16 valves (4 valves/one cylinder). The double
overhead camshaft is mounted over the cylinder head; it is driven from crankshaft through timing chain, and no push
rods are provided in the valve train system.
I5RW0C140032-01
Downloaded from www.Manualslib.com manuals search engine 1D-2 Engine Mechanical:
I5RW0C140033-01
[A]: For engine with VVT system [B]: For engine without VVT system
Downloaded from www.Manualslib.com manuals search engine Engine Mechanical: 1D-3
Camshaft Position Control (VVT Variable Valve Timing) System DescriptionS6RW0D1401002
System Description
The VVT system is an electronic control system which continuously vary and optimize the intake valve timing in
response to the engine operating condition.
The optimized intake valve timing produce such an air intake with high efficiency that both the higher power generation
and lower fuel consumption can be attained in the whole engine speed range from low to high. In the area of the
average engine load, low emission of nitrogen oxides (NOx) and high fuel efficiency can also be attained by making
the valve opening overlap between the intake and exhaust valves longer.
For the brief of the system operation, the intake valve timing is varied by the cam timing sprocket (1) which varies the
rotational phase between the intake camshaft (3) and sprocket. The rotor (2) in the cam timing sprocket is actuated by
switching or adjusting the hydraulic pressure applied to the chambers for the timing advancing (7) and/or retarding (6).
To switch or adjust the hydraulic pressure appropriately, ECM operates the oil control valve (12) with detecting the
engine speed, intake air value, throttle opening, engine coolant temperature and camshaft position (angle).
1
4
5
10
8
9
2
7
6
12
11
3
60˚ (variable angle)
Most retarded timing Most advanced timing
Exhaust valveIntake valve
Crank angle
Overlap of valves
Valve lift
I5RW0C140002-01
4. Oil passage to chamber for timing retarding 8. Oil filter 10. Oil pan
5. Oil passage to chamber for timing advancing 9. Oil pump 11. Control signal from ECM
Downloaded from www.Manualslib.com manuals search engine 1D-4 Engine Mechanical:
Oil Control Valve
The oil control valve switches and adjusts the hydraulic
pressure applied to the cam timing sprocket by moving
the spool valve (1) according to the duty pulse signals
output from the ECM. By this operation, the intake valve
timing is varied continuously. Signals output from the
ECM are the duty pulse of about 240 Hz.
Cam Timing Sprocket
The cam timing sprocket is equipped with the chambers
for timing advancing (2) and retarding (3) which are
separated by the rotor (5). The rotor rotates receiving the
hydraulic pressure applied to both the chambers. The
sprocket (1) is installed on the housing (4) and the rotor
is secured on the intake camshaft by fastening the bolts.
Therefore, the actuation of the rotor makes the phase
difference between the sprocket and intake camshaft.
Timing Advancing
When the duty ratio of the signal output from the ECM is
heavy, the spool valve (4) of the oil control valve moves
to the left (opposite direction against the coil (5)). By this
spool valve movement, the pressurized oil (1) is led into
the chambers for timing advancing and the oil in the
chambers for timing retarding is drained. This operations
actuate the rotor (3) and result in the advanced timing of
the intake valve.Timing Holding
When the duty ratio of the signal output from the ECM
shows that of holding, the spool valve of the oil control
valve is located at hold position. Because this condition
generates no oil pressure changes in both chambers,
the rotor is fixed at a target position.
Timing Retarding
When the duty ratio of the signal output from the ECM is
light, the spool valve of the oil control valve moves to the
right (head for the coil). By this spool valve movement,
the pressurized oil is led into the chambers for timing
retarding and the oil in the chambers for timing
advancing is drained. This operations actuate the rotor
and result in the retarded timing of the intake valve.
6. Seal
2. Drain
1
I5RW0C140034-01
12
3 4
5
6
I3RH0B140004-01
1
2
5
4
3
I5RW0C140035-01
I5RW0C140036-01
I5RW0C140037-01
Downloaded from www.Manualslib.com manuals search engine Engine Mechanical: 1D-5
Targeted Timing Varying Operation
Diagnostic Information and Procedures
Compression CheckS6RW0D1404001
Check compression pressure on all 4 cylinders as
follows:
1) Warm up engine to normal operating temperature.
2) Stop engine after warming up.
NOTE
After warming up engine, place transmission
gear shift lever in “Neutral” (shift selector
lever to “P” range for A/T model), and set
parking brake and block drive wheels.
3) Remove air cleaner assembly with air suction hose
referring to “Air Cleaner Assembly Removal and
Installation”.
4) Remove cylinder head upper cover.
5) Remove ignition coil assemblies and all spark plugs
referring to “Spark Plug Removal and Installation in
Section 1H”.
6) Disconnect fuel injector wires at the coupler.7) Install special tools (Compression gauge) into spark
plug hole.
Special tool
(A): 09915–64512
(B): 09915–64530
(C): 09915–67010 Driving condition Valve timing Target of control Effect
Engine running at idle
speedMost retardedTo shorten the valve opening overlap in
order to prevent the exhaust gas
counterflow to intake manifold.Stabilization of the engine
rotation at idle speed.
Average engine load
rangeTo the advanced
sideTo lengthen the valve opening overlap
in order to enhance the internal
exhaust gas recirculation and reduce
the pumping loss.Improvement of the fuel
efficiency.
Lowering of the exhaust
emission.
Light engine load
rangeTo the retarded sideTo shorten the valve opening overlap in
order to prevent the exhaust gas
counterflow to intake manifold.Keeping of the engine stability.
Low or average
engine speed range
with heavy engine
loadTo the advanced
sideTo advance the closing timing of the
intake valve in order to improve the
volumetric efficiency.Improvement of generating the
engine torque at low and
average engine speed.
High engine speed
range with heavy
engine loadTo the retarded sideTo retard the closing timing of the
intake valve in order to improve the
volumetric efficiency.Improvement of generating the
engine power.
Low engine coolant
temperatureMost retardedTo shorten the valve opening overlap in
order to prevent the exhaust gas
counterflow to intake manifold and
reduce the fuel increasing.
To slow the fast idle speed of the
engine as a result of stabilizing the
engine idling.Stabilization of the fast idling of
the engine.
Improvement of the fuel
efficiency.
At engine starting and
stoppingMost retardedTo shorten the valve opening overlap in
order to prevent the exhaust gas
counterflow to intake manifold.Improvement of start ability.
(A)
(C)
(B)
I3RH0B140009-01
Downloaded from www.Manualslib.com manuals search engine 1D-6 Engine Mechanical:
8) Disengage clutch (1) (to lighten starting load on
engine) for M/T vehicle, and depress accelerator
pedal (2) all the way to make throttle fully open.
9) Crank engine with fully charged battery, and read the
highest pressure on compression gauge.
NOTE
• For measuring compression pressure,
crank engine at least 250 r/min. by using
fully charged battery.
• If measured compression pressure is
lower than limit value, check installation
condition of special tool. If it is properly
installed, possibility is compression
pressure leakage from where piston ring
and valve contact.
Compression pressure
Standard: 1400 kPa (14.0 kgf/cm2, 199.0 psi)
Limit: 1100 kPa (11.0 kgf/cm2, 156.0 psi)
Max. difference between any two cylinders: 100
kPa (1.0 kgf/cm
2, 14.2 psi)
10) Carry out Steps 7) through 9) on each cylinder to
obtain 4 readings.
11) After checking, install spark plugs and ignition coil
assemblies with high-tension cord referring to “Spark
Plug Removal and Installation in Section 1H”.
12) Connect ignition coil couplers.
13) Connect fuel injector wires at the coupler.
14) Install cylinder head upper cover.
15) Install air cleaner assembly with air section hose
referring to “Air Cleaner Assembly Removal and
Installation”.
Engine Vacuum CheckS6RW0D1404002
The engine vacuum that develops in the intake line is a
good indicator of the condition of the engine. The
vacuum checking procedure is as follows:
1) Warm up engine to normal operating temperature.
NOTE
After warming up engine, place transmission
gear shift lever in “Neutral” (shift selector
lever to “P” range for A/T model), and set
parking brake and block drive wheels.
2) Stop engine and turn off the all electric switches.
3) Remove air cleaner assembly with air suction hose
referring to “Air Cleaner Assembly Removal and
Installation”.
4) Remove PCV hose (1) from PCV valve (2).
5) Connect special tool (Vacuum gauge) to PCV hose
(1).
Special tool
(A): 09915–67311
6) Blind PCV valve (2) using tape (3) or the like.I2RH0B140005-01
12
I5RW0C140038-01
(A)
1
2
3
I5RW0A140003-02