Mitsubishi Eclipse / Eclipse Spyder (2000-2002). Service and repair manual — part 76

GENERAL DESCRIPTION

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-3

.

G EN ER A L DESC RIPTIO N

M1131000100154

The Multiport Fuel Injection System consists of
sensors, actuators and the engine control module
(ECM) <M/T> or powertrain control module (PCM)
<A/T>. The sensors detect the engine condition. The
module controls the system based on signals from
these sensors. The actuators work under the control
of the ECM <M/T> or PCM <A/T>. The ECM <M/T>
or PCM <A/T> carries out activities such as fuel
injection control, idle air control, and ignition timing
control. In addition, the ECM <M/T> or PCM <A/T>
has several diagnostic test modes which simplify
troubleshooting when a problem develops. In
addition, the ECM <M/T> or PCM <A/T> is equipped
with several diagnostic test modes which simplify
troubleshooting when a problem develops.

FUEL INJECTION CONTROL
The ECM <M/T> or PCM <A/T> controls injector
drive times and injector timing to supply the optimum
air/fuel mixture to the engine according to the
continually-changing engine operation conditions. A
single injector is mounted at the intake port of each
cylinder. The fuel pump supplies pressurized fuel
from the fuel tank to the fuel injectors. The fuel
pressure regulator controls the fuel pressure. Thus,
the regulated fuel is distributed to each injector. Fuel
is normally injected for each cylinder every two
rotations of the crankshaft. The firing order is 1-3-4-
2. Each cylinder has a dedicated fuel injector. This is
called "multiport." The ECM <M/T> or PCM <A/T>
provides a richer air/fuel mixture by carrying out
"open-loop" control when the engine is cold or
running under high load conditions. Thus, engine
performance is maintained. In addition, when the
engine is under normal operating temperature after
warming-up, the ECM <M/T> or PCM <A/T> controls
the air/fuel mixture according to the heated oxygen
sensor signal. This control is a "closed-loop" control.
The closed-loop control achieves the theoretical air/
fuel mixture ratio where the catalytic converter can
obtain the maximum cleaning performance.

IDLE AIR CONTROL
The engine control module controls the amount of air
that bypasses the throttle valve according to
changes in idling conditions and engine load during
idling. Thus, idle speed is kept at an optimum speed.
The ECM <M/T> or PCM <A/T> drives the idle air

control (IAC) motor according to engine coolant
temperature, A/C, and other electrical load. Thus,
idle speed is kept at an optimum speed. In addition,
when the air conditioning switch is turned off and on
while the engine is idling, the IAC motor adjusts the
throttle valve bypass air amount. Thus, idle speed is
maintained at constant speed regardless of various
engine load conditions.

IGNITION TIMING CONTROL
The ignition power transistor located in the ignition
primary circuit turns on and off to control primary
current flow to the ignition coil. This maintains
ignition timing at an optimum level regardless of
various engine operating conditions. The ECM <M/
T> or PCM <A/T> determines the ignition timing
according to engine speed, intake air volume, engine
coolant temperature, and atmospheric pressure.

DIAGNOSTIC TEST MODE

•

When a fault is detected in any of the sensors or
actuators related to emission control, the
SERVICE ENGINE SOON/MALFUNCTION
INDICATOR LAMP illuminates to warn the driver.

•

When a fault is detected in one of the sensors or
actuators, a diagnostic trouble code
corresponding to the fault is stored in the ECM
<M/T> or PCM <A/T>.

•

The RAM data inside the ECM <M/T> or PCM
<A/T> that is related to the sensors and actuators
can be read with the scan tool. In addition, the
actuators can be controlled by the scan tool
MUT-II (MB991502) under certain circumstances.

OTHER CONTROL FUNCTIONS

1. Fuel Pump Control Turns on the fuel pump relay

so that current is supplied to the fuel pump while
the engine is cranking or running.

2. A/C Compressor Clutch Relay Control Turns on

and off the air conditioning compressor clutch.

3. Evaporative Emission Purge Control (Refer to

GROUP 17, Emission Control System

−

Evaporative Emission Control System

−

General

Information

P.17-90

.)

4. EGR Control (Refer to GROUP 17, Emission

Control System

−

Exhaust Gas Recirculation

(EGR) System

−

General Information

P.17-96

.)

GENERAL DESCRIPTION

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-4

MULTIPORT FUEL INJECTION (MFI) SYSTEM DIAGRAM

NOTE: For the vacuum hose routing, refer to
GROUP 17, Vacuum Hoses

P.17-84

.

AK000740

1 HEATED OXYGEN SENSOR (FRONT)
2 VOLUME AIR FLOW SENSOR
3 INTAKE AIR TEMPERATURE SENSOR
4 THROTTLE POSITION SENSOR
5 CAMSHAFT POSITION SENSOR
6 CRANKSHAFT POSITION SENSOR
7 BAROMETRIC PRESSURE SENSOR
8 ENGINE COOLANT TEMPERATURE SENSOR
9 KNOCK SENSOR
10 HEATED OXYGEN SENSOR (REAR)
11 MANIFOLD DIFFERENTIAL PRESSURE SENSOR
12 FUEL TANK DIFFERENTIAL PRESSURE SENSOR

POWER SUPPLY
VEHICLE SPEED SENSOR
A/C SWITCH
PARK/NEUTRAL POSITION SWITCH <A/T>
POWER STEERING PRESSURE SWITCH
IGNITION SWITCH - ST

1 INJECTOR
2 EVAPORATIVE EMISSION
PURGE SOLENOID
3 IDLE AIR CONTROL MOTOR
4 EGR SOLENOID
5 EVAPORATIVE EMISSION
VENTILATION SOLENOID\

FUEL PUMP RELAY
MULTIPORT FUEL INJECTION
(MFI) RELAY
A/C COMPRESSER CLUTCH RELAY
SERVICE ENGINE SOON/
MALFUNCTION INDICATOR LAMP
DIAGNOSTIC OUTPUT
IGNITION COIL,
IGNITION POWER TRANSISTER

ECM <M/T>
PCM <A/T>

SENSE

DECIDE

ACT

A

E

AIR INLET

3 INTAKE AIR
TEMPERATURE SENSOR

3 IDLE AIR
CONTROL
MOTOR

7,

2

VOLUME AIR FLOW SENSOR
(WITH BAROMETRIC
PRESSURE SENSOR)

12 FUEL TANK
DIFFERENTIAL
PRESSURE
SENSOR

EVAPORATIVE
EMISSION
CANISTER

FUEL TANK

5 EVAPORATIVE
EMISSION
VENTILATION
SOLENOID

2 EVAPORATIVE

EMISSION

PURGE

SOLENOID

4 EGR
SOLENOID

4 THROTTLE POSITION
SENSOR

MANIFOLD
DIFFERENTIAL
PRESSURE
SENSOR
11

EGR
VALVE

VACUUM

CONTROL

VALVE

M*1

*2

FROM

FUEL

PUMP

TO

FUEL

TANK

FUEL

PRESSURE

REGULATOR

1

8

INJE-
CTOR

5 CAMSHAFT

POSITION

SENSOR

ENGINE COOLANT

TEMPERATURE

SENSOR

1 HEATED OXYGEN SENSOR (FRONT)

9 KNOCK SENSOR

6 CRANK SHAFT
POSITION SENSOR

10 HEATED OXYGEN SENSOR (REAR)

NOTE

*1 : Manifold port
*2 : Restrictor

AA

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

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M U LTIPO R T FU EL IN JEC TIO N (M FI) D IA G N O SIS

TROUBLESHOOTING STRATEGY

M1131008500156

Use these steps to plan your diagnostic strategy. If
you follow them carefully, you will be sure to have
exhausted most of the possible ways to find an MFI
fault.
1. Gather as much information as possible about the

complaint from the customer.

2. Verify that the condition described by the

customer exists.

3. Check the vehicle for any MFI Diagnostic Trouble

Code (DTC).

4. If you cannot verify the condition and there are no

DTCs, the malfunction is intermittent. For
information on how to cope with intermittent
malfunctions, refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

−

How

to cope with Intermittent Malfunction

P.00-6

.

5. If you can verify the condition but there are no

DTCs, or the system cannot communicate with
the scan tool, refer to the trouble symptom
classification table.

6. If there is a DTC, record the number of the code,

then erase the code from the memory using the
scan tool.

NOTE: If a DTC is erased, its "freeze frame" data will
be also erased and the readiness test status will be
reset. If necessary, store the "freeze frame" data
before erasing the DTC.
7. Reconfirm the malfunction symptom and carry out

a test drive with the drive cycle pattern.

8. If DTC is set again, carry out an inspection with

the inspection procedure for diagnostic trouble
codes of that code.

9. If DTC is not set again, the malfunction is

intermittent. For information on how to cope with
intermittent malfunctions, refer to GROUP 00,
How to Use Troubleshooting/Inspection Service
Points

−

How to cope with Intermittent Malfunction

P.00-6

.

10.After repairs are completed, conduct a road test

duplicating the complaint set conditions to confirm
the malfunction has been eliminated.

NOTE: If the engine control module (ECM) <M/T> or
powertrain control module (PCM) <A/T> is replaced,
the immobilizer-ECU should be replaced together
with it. Each ECM <M/T> or PCM <A/T> has an
individual information for immobilizer-ECU, and the
individual information is registered in the immobilizer-
ECU.

TROUBLE CODE DIAGNOSIS

M1131008600142

SERVICE ENGINE SOON/MALFUNCTION INDICATOR
LAMP
Among the on-board diagnostic items, a Service Engine Soon/
Malfunction Indicator Lamp illuminates to notify the driver of an
emission control malfunction.
However, when an irregular signal returns to normal and the
engine control module (ECM) <M/T> or powertrain control
module (PCM) <A/T> judges that it has returned to normal, the
Service Engine Soon/Malfunction Indicator Lamp is switched
off.
Moreover, when the ignition switch is turned off, the lamp is
switched off. Even if the ignition switch is turned on again, the
lamp does not illuminate until the malfunction is detected.
Immediately after the ignition switch is turned on, the Service
Engine Soon/Malfunction Indicator Lamp is lit for five seconds
to indicate that the Service Engine Soon/Malfunction Indicator
Lamp operates normally.

AK000054

AB

SERVICE ENGINE SOON/
MALFUNCTION INDICATOR LAMP

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-6

Items Indicated by the Service Engine Soon/Malfunction Indicator Lamp

DTC NO.

ITEMS

-

Engine control module (ECM) <M/T> or Powertrain control module (PCM) <A/T>
malfunction

P0101

Volume air flow circuit range/performance problem

P0102

Volume air flow circuit low input

P0103

Volume air flow circuit high input

P0107

Barometric pressure circuit low input

P0108

Barometric pressure circuit high input

P0111

Intake air temperature circuit range/performance problem

P0115

Engine coolant temperature circuit high input

P0116

Engine coolant temperature circuit range/performance problem

P0117

Engine coolant temperature circuit low input

P0121

Throttle position circuit range/performance problem

P0122

Throttle position circuit low input

P0123

Throttle position circuit high input

P0128

Coolant thermostat malfunction

P0130

O

2

sensor circuit malfunction (sensor 1)

P0133

O

2

sensor circuit slow response (sensor 1)

P0134O

2

sensor circuit no activity detected (sensor 1)

P0135

O

2

sensor heater circuit malfunction (sensor 1)

P0136

O

2

sensor circuit malfunction (sensor 2)

P0139

O

2

sensor circuit slow response (sensor 2)

P0141

O

2

sensor heater circuit malfunction (sensor 2)

P0171

System too lean

P0172

System too rich

P0201

Injector circuit malfunction-cylinder 1

P0202

Injector circuit malfunction-cylinder 2

P0203

Injector circuit malfunction-cylinder 3

P0204Injector circuit malfunction-cylinder 4

P0300

Random misfire detected

P0301

Cylinder 1 misfire detected

P0302

Cylinder 2 misfire detected

P0303

Cylinder 3 misfire detected

P0304Cylinder 4

misfire detected

P0335

Crankshaft position sensor circuit malfunction

P0340

Camshaft position sensor circuit malfunction

P0401

Exhaust gas recirculation flow insufficient detected

P0403

Exhaust gas recirculation solenoid malfunction

P0421

Warm up catalyst efficiency below threshold (bank 1)

P0442

Evaporative emission control system leak detected