Multiport Fuel Injection (MFI) System
DESCRIPTIONNCEC0014Input/Output Signal ChartNCEC0014S01
Sensor Input Signal to ECMECM func-
tionActuator
Camshaft position sensor Engine speed and piston position
Fuel injec-
tion & mix-
ture ratio
controlInjector Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Heated oxygen sensor 1 (front) Density of oxygen in exhaust gas
Throttle position sensorThrottle position
Throttle valve idle position
PNP switch Gear position
Vehicle speed sensor or ABS actuator and
electric unit (control unit)Vehicle speed
Ignition switch Start signal
Air conditioner switch Air conditioner operation
Knock sensor Engine knocking condition
Electrical load Electrical load signal
Battery Battery voltage
Power steering oil pressure switch Power steering operation
Heated oxygen sensor 2 (rear)* Density of oxygen in exhaust gas
* Under normal conditions, this sensor is not for engine control operation.
Basic Multiport Fuel Injection SystemNCEC0014S02The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the camshaft position sensor and the mass air
flow sensor.
Various Fuel Injection Increase/Decrease CompensationNCEC0014S03In addition, the amount of fuel injected is compensated to improve engine performance under various oper-
ating conditions as listed below.
IDuring warm-up
IWhen starting the engine
IDuring acceleration
IHot-engine operation
IWhen selector lever is changed from ªNº to ªDº (CVT models only)
IHigh-load, high-speed operation
IDuring deceleration
IDuring high engine speed operation
IDuring high vehicle speed operation (M/T models)
IExtremely high engine coolant temperature
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTIONSR20DE
Multiport Fuel Injection (MFI) System
EC-23
If results are unsatisfactory, perform Fuel Pressure Regulator
Check, EC-SR-32.
Fuel Pressure Regulator CheckNCEC00261. Stop engine and disconnect fuel pressure regulator vacuum
hose from intake manifold.
2. Plug intake manifold with a rubber cap.
3. Connect variable vacuum source to fuel pressure regulator.
4. Start engine and read indication of fuel pressure gauge as
vacuum is changed.
Fuel pressure should decrease as vacuum increases. If results
are unsatisfactory, replace fuel pressure regulator.
IDo not reuse O-ring.
Injector
REMOVAL AND INSTALLATIONNCEC00271. Release fuel pressure to zero.
2. Disconnect fuel hoses and injector harness connectors.
3. Remove fuel tube assemblies with fuel injectors.
4. Expand and remove clips securing fuel injectors.
5. Extract fuel injectors straight from fuel tubes.
IBe careful not to damage injector nozzles during removal.
IDo not bump or drop fuel injectors.
IDo not disassemble or adjust fuel injectors.
6. Install fuel injectors with extra care for O-rings.
IDo not reuse O-rings.
IUse bare hands to install O-rings. Do not wear gloves.
IApply a coat of new engine oil (with a low viscosity of
5W-30, etc.) to O-rings before installation.
IDo not use solvent to clean O-rings and other parts.
IMake sure that O-rings and other parts are clean and free
from foreign particles.
IBe careful not to damage O-rings with service tools, clip
or finger nails. Do not expand or twist O-rings. If
stretched, do not insert them into fuel tubes immediately
after stretching.
IAlways insert O-rings straight into fuel tubes. Do not tilt
or rotate them during installation.
7. Position clips in grooves on fuel injectors.
IMake sure that protrusions of fuel injectors are aligned
with cutouts of clips after installation.
8. Align protrusions of fuel tubes with those of fuel injectors.
Insert fuel injectors straight into fuel tubes.
9. After properly inserting fuel injectors, check to make sure that
fuel tube protrusions are engaged with those of fuel injectors,
and that flanges of fuel tubes are engaged with clips.
SEF718B
SEF927W
BASIC SERVICE PROCEDURESR20DE
Fuel Pressure Regulator Check
EC-32
ACTIVE TEST MODENCEC0034S07
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJEC-
TIONIEngine: Return to the original
trouble condition
IChange the amount of fuel injec-
tion using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.IHarness and connector
IFuel injectors
IHeated oxygen sensor 1 (front)
IACV-AAC/V
OPENINGIEngine: After warming up, idle
the engine.
IChange the IACV-AAC valve
opening steps using CONSULT-
II.Engine speed changes according
to the opening steps.IHarness and connector
IIACV-AAC valve
ENG COOLANT
TEMPIEngine: Return to the original
trouble condition
IChange the engine coolant tem-
perature indication using CON-
SULT-II.If trouble symptom disappears, see
CHECK ITEM.IHarness and connector
IEngine coolant temperature sen-
sor
IFuel injectors
IGNITION TIM-
INGIEngine: Return to the original
trouble condition
ITiming light: Set
IRetard the ignition timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.IAdjust initial ignition timing
POWER BAL-
ANCEIEngine: After warming up, idle
the engine.
IAir conditioner switch ªOFFº
IShift lever ªNº
ICut off each injector signal one
at a time using CONSULT-II.Engine runs rough or dies.IHarness and connector
ICompression
IInjectors
IPower transistor
ISpark plugs
IIgnition coils
COOLING FANIIgnition switch: ON
ITurn the cooling fan ªONº and
ªOFFº using CONSULT-II.Cooling fan moves and stops.IHarness and connector
ICooling fan motor
FUEL PUMP
RELAYIIgnition switch: ON
(Engine stopped)
ITurn the fuel pump relay ªONº
and ªOFFº using CONSULT-II
and listen to operating sound.Fuel pump relay makes the operat-
ing sound.IHarness and connector
IFuel pump relay
SELF-LEARNING
CONTIIn this test, the coefficient of self-learning control mixture ratio returns to the original coefficient by touching
ªCLEARº on the screen.
PURG VOL
CONT/VIEngine: After warming up, idle
the engine.
IChange the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-II.Engine speed changes according
to the opening percent.IHarness and connector
IEVAP canister purge volume
control solenoid valve
IDLE AIR VOL
LEARNIIn this test, the idle air volume that keeps the engine within the specified range is memorized in ECM.
DTC CONFIRMATION MODENCEC0034S08SRT STATUS ModeNCEC0034S0801For details, refer to ªSYSTEM READINESS TEST (SRT) CODEº,
EC-SR-49.
SRT Work Support Mode
This mode enables a technician to drive a vehicle to set the SRT
while monitoring the SRT status.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONSR20DE
CONSULT-II (Cont'd)
EC-75
Component DescriptionNCEC0577The crankshaft position sensor (OBD) is located on the transmis-
sion housing facing the gear teeth (cogs) of the flywheel or drive
plate. It detects the fluctuation of the engine revolution.
The sensor consists of a permanent magnet, core and coil.
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 magnetic field near the sensor to
change.
Due to the changing magnetic field, the voltage from the sensor
changes.
The ECM receives the voltage signal and detects the fluctuation of
the engine revolution.
This sensor is not used to control the engine system.
It is used only for the on board diagnosis.
ECM Terminals and Reference ValueNCEC0578Specification data are reference values and are measured between each terminal and 48 (ECM ground).
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (AC Voltage)
58 B Sensors' ground[Engine is running]
IWarm-up condition
IIdle speedApproximately 0V
65 WCrankshaft position sen-
sor (OBD)[Engine is running]
IWarm-up condition
IIdle speed3 - 5V (AC range)
SEF721W
[Engine is running]
IEngine speed is 2,000 rpm6 - 9V (AC range)
SEF722W
On Board Diagnosis LogicNCEC0579
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0335
0335IThe proper pulse signal from the crankshaft position sen-
sor (OBD) is not sent to ECM while the engine is running
at the specified engine speed.IHarness or connectors
(The crankshaft position sensor (OBD) circuit is
open.)
ICrankshaft position sensor (OBD)
SEF956N Core
Permanent magnetCoil
SEF226X Crankshaft position
sensor (OBD) harness connector
Cooling fan motor
(Left side)
DTC P0335 CRANKSHAFT POSITION SENSOR (CKPS) (OBD)SR20DE
Component Description
EC-234
DescriptionNCEC0279SYSTEM DESCRIPTIONNCEC0279S01
Sensor Input Signal to ECMECM func-
tionActuator
Camshaft position sensor Engine speed
ECM IACV-AAC valve Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Throttle position sensor Throttle position
PNP switch Park/Neutral position
Air conditioner switch Air conditioner operation
Power steering oil pressure switch Power steering load signal
Battery Battery voltage
Vehicle speed sensor or ABS actuator and
electric unit (control unit)Vehicle speed
Cooling fan Cooling fan operation
Electrical load Electrical load signal
This system automatically controls engine idle speed to a specified
level. Idle speed is controlled through fine adjustment of the
amount of air which by-passes the throttle valve via IACV-AAC
valve. The IACV-AAC valve changes the opening of the air by-pass
passage to control the amount of auxiliary air. This valve is actu-
ated by a step motor built into the valve, which moves the valve in
the axial direction in steps corresponding to the ECM output sig-
nals. One step of IACV-AAC valve movement causes the respec-
tive opening of the air by-pass passage. (i.e. when the step
advances, the opening is enlarged.) The opening of the valve is
varied to allow for optimum control of the engine idling speed. The
crankshaft position sensor (POS) detects the actual engine speed
and sends a signal to the ECM. The ECM then controls the step
position of the IACV-AAC valve so that engine speed coincides with
the target value memorized in ECM. The target engine speed is the
lowest speed at which the engine can operate steadily. The opti-
mum value stored in the ECM is determined by taking into consid-
eration various engine conditions, such as during warm up,
deceleration, and engine load (air conditioner, power steering, cool-
ing fan operation and electrical load).
COMPONENT DESCRIPTIONNCEC0279S02The IACV-AAC valve is operated by a step motor for centralized
control of auxiliary air supply. This motor has four winding phases
and is actuated by the output signals of ECM which turns ON and
OFF two windings each in sequence. Each time the IACV-AAC
valve opens or closes to change the auxiliary air quantity, the ECM
sends a pulse signal to the step motor. When no change in the
auxiliary air quantity is needed, the ECM does not issue the pulse
signal. A certain voltage signal is issued so that the valve remains
at that particular opening.
SEF937W
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð
AUXILIARY AIR CONTROL (AAC) VALVESR20DE
Description
EC-263
Component DescriptionNCEC0327The crankshaft position sensor (OBD) is located on the transmis-
sion housing facing the gear teeth (cogs) of the flywheel or drive
plate. It detects the fluctuation of the engine revolution.
The sensor consists of a permanent magnet, core and coil.
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 magnetic field near the sensor to
change.
Due to the changing magnetic field, the voltage from the sensor
changes.
The ECM receives the voltage signal and detects the fluctuation of
the engine revolution.
This sensor is not used to control the engine system.
It is used only for the on board diagnosis.
ECM Terminals and Reference ValueNCEC0328Specification data are reference values and are measured between each terminal and 48 (ECM ground).
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (AC Voltage)
58 B Sensors' ground[Engine is running]
IWarm-up condition
IIdle speedApproximately 0V
65 WCrankshaft position sen-
sor (OBD)[Engine is running]
IWarm-up condition
IIdle speed3 - 5V (AC range)
SEF721W
0.2 ms
[Engine is running]
IEngine speed is 2,000 rpm6 - 9V (AC range)
SEF722W
0.2 ms
On Board Diagnosis LogicNCEC0329
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P1336
1336IA chipping of the flywheel or drive plate gear tooth (cog)
is detected by the ECM.IHarness or connectors
ICrankshaft position sensor (OBD)
IDrive plate/Flywheel
SEF956N Core
Permanent magnetCoil
SEF226X Crankshaft position
sensor (OBD) harness connector
Cooling fan motor
(Left side)
DTC P1336 CRANKSHAFT POSITION SENSOR
(CKPS) (OBD) (COG)SR20DE
Component Description
EC-290
CD AUTOCHANGER
Symptom Possible cause Repair order
No play of the CD after CD play
button is pushed.1. Radio
(The radio is not working.)
2. Harness connection
(Magazine does not eject.)
3. Discs
4. Magazine does not eject or a
disc remains in CD player.
5. Changer1. Remove the radio for repair.
2. Check harness connection.
3. Inspect disc.
(Refer to testing magazines and discs.)
4. Reset the changer.
(Disconnect harness connector at the changer
and reconnect after 30 sec.)
5. Remove the changer for repair.
CD skipping. 1. Rough road driving
2. Discs
3. Bracket
4. Changer1. System is not malfunctioning.
2. Inspect discs.
(Refer to testing magazines and discs.)
3. Check and repair bracket and installation
of changer.
4. Remove the changer for repair.
Error code [NO DISC] is shown
on the radio after CD play button
is pressed.1. Magazine setting
2. Magazine
3. Changer1. Confirm the magazine is pushed completely.
2. Inspect magazine.
(Refer to testing magazines and discs.)
3. Remove the changer for repair.
Testing magazines and discs
1. Confirm discs are installed correctly into the magazine (not upside down).
2. Visually inspect/compare the customer’s discs with each other and other discs.
Identify any of the following conditions:
Discs with a large outside diameter. [Normal size is 120 mm (4.72 in).]
Discs with rough or lipped edges.
Discs with excessive thickness [Normal size is 1.2 mm (0.047 in).]
Discs with scratches, abrasions, or pits on the surface.
Discs with grease/oil, fingerprints, foreign material.
Discs are warped due to excessive heat exposure.
3. Slide/place the discs in and out of the various magazine positions.
Identify any discs and/or positions that require additional force for placement/ejection. If interference
(sticking, excessive tensions) is found, replace the magazine or the discs.
Note:
Discs which are marginally out of specification (ex. dirty, scratched and so on) may play correctly
on a home stereo.
However, when used in the automative environment skipping may occur due to the added vehicle
movement and/or vibration due to road conditions. Autochangers should not be replaced when
discs are at fault.
Use a soft damp cloth to wipe the discs starting from the center outward in radial direction. Never
use chemical cleaning solutions to clean the discs.
AUDIO
Trouble Diagnoses (Cont’d)
EL-227
Precautions for Multiport Fuel Injection
System or Engine Control Module
lBefore connecting or disconnecting any harness connector
for the multiport fuel injection system or ECM (Engine Con-
trol Module):
Turn ignition switch to ªLOCKº position.
Disconnect negative battery terminal.
Otherwise, there may be damage to ECM.
lBefore disconnecting pressurized fuel line from fuel pump to
injectors, be sure to release fuel pressure.
lBe careful not to jar components such as ECM and mass air
flow sensor.
Precautions for Three Way Catalyst
If a large amount of unburned fuel flows into the catalyst, the
catalyst temperature will be excessively high. To prevent this,
follow the instructions below:
lUse unleaded gasoline only. Leaded gasoline will seriously
damage the three way catalyst.
lWhen checking for ignition spark or measuring engine
compression, make tests quickly and only when necessary.
lDo not run engine when the fuel tank level is low, otherwise
the engine may misfire causing damage to the catalyst.
Do not place the vehicle on flammable material. Keep flammable
material off the exhaust pipe and the three way catalyst.
Precautions for Turbocharger
The turbocharger turbine revolves at extremely high speeds and
becomes very hot. Therefore, it is essential to maintain a clean
supply of oil flowing through the turbocharger and to follow all
required maintenance instructions and operating procedures.
lAlways use the recommended oil. Follow the instructions for
proper time to change the oil and proper oil level.
lAvoid accelerating engine to a high rpm immediately after
starting.
lIf engine had been operating at high rpm for an extended
period of time, let it idle for a few minutes prior to shutting it
off.
Precautions for Engine Oils
Prolonged and repeated contact with used engine oil may cause
skin cancer. Try to avoid direct skin contact with used oil.
If skin contact is made, wash thoroughly with soap or hand
cleaner as soon as possible.
HEALTH PROTECTION PRECAUTIONS
lAvoid prolonged and repeated contact with oils, particularly
used engine oils.
SGI787
SGI292 Cold engine
PRECAUTIONS
GI-6