Mitsubishi Eclipse. Manual — part 365

GENERAL INFORMATION

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-3

GENERAL INFORMATION

M1131000100961

.

The Multiport Fuel Injection System consists of sen-
sors which detect the engine conditions, the ENGINE
CONTROL MODULE (ECM) <M/T>/POWERTRAIN
CONTROL MODULE (PCM) <A/T> which controls
the system based on signals from these sensors,
and actuators which operate under the control of the
ECM <M/T>/PCM <A/T>. The ECM <M/T>/PCM
<A/T> carries out activities such as fuel injection con-
trol, idle air control, and ignition timing control. In
addition, the ECM <M/T>/PCM <A/T> is equipped
with several diagnostic test modes which simplify
troubleshooting when a problem develops.

.

FUEL INJECTION CONTROL
The injection drive times and injector timing are con-
trolled so that the optimum air/fuel mixture is sup-
plied to the engine to correspond to the
continually-changing engine operation conditions. A
single injector is mounted at the intake port of each
cylinder. Fuel is sent under pressure from the fuel
tank to the fuel injectors by the fuel pump, with the
pressure being regulated by the fuel pressure regula-
tor. The regulated fuel is distributed to each of the
injectors. Fuel injection is normally carried out once
for each cylinder for every two rotations of the crank-
shaft. The firing order is 1-2-3-4-5-6. Each cylinder
has a dedicated fuel injector. This is called multiport.
The ECM <M/T>/PCM <A/T> provides a richer
air/fuel mixture by carrying out "open-loop" control
when the engine is cold or operating under high load
conditions in order to maintain engine performance.
In addition, when the engine is under normal operat-
ing temperature after warming-up, the ECM
<M/T>/PCM <A/T> controls the air/fuel mixture by
using the heated oxygen sensor signal to carry out
"closed-loop" control. The closed-loop control
achieves the theoretical air/fuel mixture ratio where
the catalytic converter can obtains the maximum
cleaning performance.

.

IDLE AIR CONTROL
The idle speed is kept at the optimum speed by con-
trolling the amount of air that bypasses the throttle
valve in accordance with changes in idling conditions
and engine load during idling. The ECM <M/T>/PCM
<A/T> drives the idle air control (IAC) motor to keep
the engine running at the pre-set idle target speed in
accordance with the engine coolant temperature and

A/C and other electrical load. In addition, when the
A/C switch is turned off and on while the engine is
idling, the IAC motor adjusts the throttle valve bypass
air amount according to the engine load conditions to
avoid fluctuations in the engine speed.

.

IGNITION TIMING CONTROL
The ignition power transistor located in the ignition
primary circuit turns ON and OFF to control the pri-
mary current flow to the ignition coil. This controls
the ignition timing to provide the optimum ignition
timing with respect to the engine operating condi-
tions. The ignition timing is determined by the ECM
<M/T>/PCM <A/T> from engine speed, intake air vol-
ume, engine coolant temperature, and atmospheric
pressure.

.

DIAGNOSTIC TEST MODE

• When an abnormality is detected in one of the

sensors or actuators related to emission control,
the MALFUNCTION INDICATOR LAMP (SER-
VICE ENGINE SOON OR CHECK ENGINE
LAMP) illuminates to warn the driver.

• When an abnormality is detected in one of the

sensors or actuators, a diagnostic trouble code
corresponding to the abnormality is stored in the
ECM <M/T>/PCM <A/T>.

• The RAM data inside the ECM <M/T>/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 MB991958
(MUT-III Sub Assembly) under certain circum-
stances.

.

OTHER CONTROL FUNCTIONS

• Fuel Pump Control

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

• A/C Compressor Clutch Relay Control

Turns the compressor clutch of the A/C ON and
OFF.

• Fan Relay Control

The radiator fan and condenser fan speeds are
controlled in response to the engine coolant tem-
perature and vehicle speed.

• Generator Output Current Control

Prevents generator output current from increas-
ing suddenly and idle speed from dropping at
times such as when the headlights are turned on.

• Intake Manifold Tuning

GENERAL INFORMATION

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-4

Turns the solenoid of the variable induction ON
and OFF.

• Evaporative Emission Purge Control

(Refer to GROUP 17, Emission Control System

−

Evaporative Emission System

− General Informa-

tion.

P.17-103

)

• EGR Control

(Refer to GROUP 17, Emission Control System

−

Exhaust Gas Recirculation (EGR) System

− Gen-

eral Information.

P.17-109

)

GENERAL INFORMATION

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-5

MALTIPORT FUEL INJECTION (MFI) SYSTEM DIAGRAM
<Without variable induction system>

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

P.17-95

.

AK300834

6

FUEL TANK

CATALYTIC CONVERTER

FUEL PRESSURE
REGULATOR

M*1

*2

M*1

EGR
VALVE

FROM

FUEL

PUMP

TO

FUEL

TANK

1 LEFT BANK HEATED OXYGEN SENSOR (FRONT)
2 VOLUME AIRFLOW 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 LEFT BANK HEATED OXYGEN SENSOR (REAR)
10 RIGHT BANK HEATED OXYGEN SENSOR (FRONT)
11 RIGHT BANK HEATED OXYGEN SENSOR (REAR)
12 MANIFOLD ABSOLUTE PRESSURE SENSOR
13 FUEL TANK DIFFERENTIAL PRESSURE SENSOR
14 FUEL TEMPERATURE SENSOR
15 FUEL LEVEL SENSOR

POWER SUPPLY
VEHICLE SPEED SENSOR <M/T>
OUTPUT SHAFT SPEED SENSOR <A/T>
A/C SWITCH
TRANSMISSION RANGE SWITCH <A/T>
POWER STEERING PRESSURE SWITCH
IGNITION SWITCH - ST
KNOCK SENSOR

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

FUEL PUMP RELAY 1, 2
MULTIPORT FUEL INJECTION
(MFI) RELAY
A/C COMPRESSER CLUTCH RELAY
MALFUNCTION INDICATOR LAMP
(SERVICE ENGINE SOON OR
CHECK ENGINE LAMP)
DIAGNOSTIC OUTPUT

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

SENSE

DECIDE

ACT

NOTE

*1 : Manifold port
*2 : Restrictor

3 INTAKE AIR
TEMPERATURE SENSOR

7

VOLUME AIRFLOW SENSOR
(WITH BAROMETRIC
PRESSURE SENSOR)

3 IDLE AIR
CONTROL
MOTOR

4 THROTTLE POSITION SENSOR

12 MANIFOLD ABSOLUTE
PRESSURE SENSOR

1 INJECTOR

CHAMBER

VCV

A

4 EGR VACUUM
REGULATOR
SOLENOID VALVE

EVAPORATIVE EMISSION

2 PURGE SOLENOID

8 ENGINE

COOLANT

TEMPERATURE

SENSOR

10 RIGHT BANK

HEATED OXYGEN

SENSOR (FRONT)

11 RIGHT BANK

HEATED OXYGEN

SENSOR (REAR)

CRANKSHAFT POSITION

SENSOR

6

9 LEFT BANK HEATED
OXYGEN SENSOR (REAR)

5 CAMSHAFT
POSITION
SENSOR

14 FUEL
TEMPERATURE
SENSOR

15 FUEL LEVEL
SENSOR

13 FUEL TANK
DIFFERENTIAL
PRESSURE SENSOR

LEFT BANK
HEATED
1 OXYGEN
SENSOR
(FRONT)

EVAPORATIVE
EMISSION
CANISTER

5 EVAPORATIVE
EMISSION

VENTILATION

SOLENOID

FUEL TANK

AIR INLET

DISTRIBUTOR

AC

IGNITION
COIL

VENT VALVE

2,

E

GENERAL INFORMATION

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-6

<With variable induction system>

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

P.17-95

.

AK300835

FUEL TANK

CATALYTIC CONVERTER

FUEL PRESSURE
REGULATOR

M*1

*2

M*1

EGR
VALVE

FROM

FUEL

PUMP

TO

FUEL

TANK

NOTE

*1 : Manifold port
*2 : Restrictor

3 INTAKE AIR
TEMPERATURE SENSOR

2, 7

VOLUME AIRFLOW SENSOR
(WITH BAROMETRIC
PRESSURE SENSOR)

3 IDLE AIR
CONTROL
MOTOR

4 THROTTLE POSITION SENSOR

1 INJECTOR

E

CHAMBER

VCV

A

4 EGR VACUUM
REGULATOR
SOLENOID VALVE

2 EVAPORATIVE EMISSION

PURGE SOLENOID

8 ENGINE

COOLANT

TEMPERATURE

SENSOR

10 RIGHT BANK

HEATED OXYGEN

SENSOR (FRONT)

11 RIGHT BANK

HEATED OXYGEN

SENSOR (REAR)

6 CRANKSHAFT POSITION

SENSOR

9 LEFT BANK HEATED
OXYGEN SENSOR (REAR)

5 CAMSHAFT
POSITION
SENSOR

14 FUEL
TEMPERATURE
SENSOR

15 FUEL LEVEL
SENSOR

13 FUEL TANK
DIFFERENTIAL
PRESSURE SENSOR

1 LEFT BANK
HEATED
OXYGEN
SENSOR
(FRONT)

EVAPORATIVE
EMISSION
CANISTER

5 EVAPORATIVE
EMISSION
VENTILATION
SOLENOID

AIR INLET

DISTRIBUTOR

IGNITION
COIL

VENT VALVE

INTAKE MANIFOLD
TUNING ACTUATOR

VACUUM TANK

6 INTAKE MANIFOLD
TUNING SOLENOID

1 LEFT BANK HEATED OXYGEN SENSOR (FRONT)
2 VOLUME AIRFLOW 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 LEFT BANK HEATED OXYGEN SENSOR (REAR)
10 RIGHT BANK HEATED OXYGEN SENSOR (FRONT)
11 RIGHT BANK HEATED OXYGEN SENSOR (REAR)
12 MANIFOLD ABSOLUTE PRESSURE SENSOR
13 FUEL TANK DIFFERENTIAL PRESSURE SENSOR
14 FUEL TEMPERATURE SENSOR
15 FUEL LEVEL SENSOR

POWER SUPPLY
VEHICLE SPEED SENSOR <M/T>
OUTPUT SHAFT SPEED SENSOR <A/T>
A/C SWITCH
TRANSMISSION RANGE SWITCH <A/T>
POWER STEERING PRESSURE SWITCH
IGNITION SWITCH - ST
KNOCK SENSOR

1 INJECTOR
2 EVAPORATIVE EMISSION
PURGE SOLENOID
3 IDLE AIR CONTROL MOTOR
4 EGR VACUUM REGULATOR
SOLENOID VALVW
5 EVAPORATIVE EMISSION
VENTILATION SOLENOID
6 INTAKE MANIFOLD TUNING
SOLENOID

FUEL PUMP RELAY 1, 2
MULTIPORT FUEL INJECTION
(MFI) RELAY
A/C COMPRESSER CLUTCH RELAY
MALFUNCTION INDICATOR LAMP
(SERVICE ENGINE SOON OR
CHECK ENGINE LAMP)
DIAGNOSTIC OUTPUT

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

SENSE

DECIDE

ACT

12 MANIFOLD ABSOLUTE
PRESSURE SENSOR

AC