Mitsubishi Eclipse. Technical Information Manual (1994) — part 9

ENGINE <NON-TURBO> Control System

SYSTEM BLOCK DIAGRAM

Sensors

MAP Sensor

Engine coolant temperature sensor

Power-train control module (PCM)

Actuators

Fuel injection control

No. 1 injector

No. 2 injector

No. 3 injector

No. 4 injector

Throttle position sensor

Idle air control

Idle air control motor
(stepper motor)

Crankshaft position sensor

Ignition timing control

Ignition coil

MFI relay control (Power supply)

MFI relay (ASD relay)

I

Fuel pump control

Fuel pump relay

I

Air conditioning compressor
clutch relay control

Air conditioning compressor
clutch relay

Fan relay control

Radiator fan motor relay and air

I

Generator generating voltage
control

Generator

Power steering pressure switch

Park/Neutral position switch

Ignition

(J2 SENSE)

Tachometer control

Charging system indicator lamp

control

Tachometer

Charging system indicator lamp

C h e c k e n g i n e / m a l f u n c t i o n

,

indicator lamp control

Knock sensor

Control of indicator/warning

lamps in the instrument panel

Break switch

Diagnostic output

Power supply

RAM data transmission

MFI relay operating voltage
(ASD SENSE)

I

EGR control

Indicator/warning lamps in the

Diagnostic output terminal

Diagnostic output terminal (MUT)

I

purge solenoid

I

I - - +

EGR solenoid

I

Pulsed secondary air injection
control

i I

Pulsed secondary air injection

Battery temperature sensor

solenoid

ENGINE <NON-TURBO> Control System

MULTIPORT FUEL INJECTION (MFI) SYSTEM DIAGRAM

Heated oxygen sensor (Front)

Manifold absolute pressure sensor

intake air temperature sensor
Throttle position sensor
Camshaft position sensor
Crankshaft position sensor

Engine coolant temperature sensor

Knock sensor
Heated oxygen sensor (Rear)

l

Power supply

l

Vehicle speed sensor

l

switch

l

Park/Neutral position switch

l

Power steering pressure switch

l

Ignition switch-IG (J2 sense)

l

Brake switch

l

MFI relay (ASD relay)

al injector
a2 Evaporative emission purge solenoid
a3 Idle air control motor

EET solenoid
Ignition coil

Pulsed secondary air injection solenoid

l

Fuel pump relay

Multiport fuel injection (MFI) relay

(ASD relay)

l

Air conditioning compressor clutch relay

l

Check engine/Malfunction indicator lamp

l

Diagnostic output

l

Fan motor relay

l

Generator

l

Engine speed meter

l

Changing warning light

l

Indicator/warning lamps in the instrument
panel

Powertrain control

module (PCM)

I

I

Evaporative emission
purge solenoid

Throttle

valve

. .

Air

transducer solenoid

-

-

-

From fuel pump

Engine

Air cleaner

Manifold absolute
pressure sensor

Intake air temperature sensor

Camshaft position sensor

Heated oxygen
sensor (Front)

I

I I

solenoid

I
I

I

coolant temperature sensor

Knock sensor

Crankshaft position sensor

oxygen

ENGINE <NON-TURBO> Control Svstem

SENSORS

MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR

The powertrain control module (PCM) supplies 5
volts direct current to the MAP sensor. The MAP

mospheric air pressure from the MAP sensor

sensor converts intake manifold pressure into

age. While the engine operates, the PCM

age. The PCM monitors the MAP sensor output

mines intake manifold pressure from the MAP

voltage. As vacuum increases, MAP sensor voltage

sor voltage. Based on MAP sensor voltage and

decreases proportionately. Also, as vacuum

inputs from other sensors, the PCM adjusts spark

advance and the air/fuel mixture.

creases, MAP sensor voltage increases
ately.

At wide-open-throttle and during cranking, before
the engine starts running, the PCM determines

The MAP sensor mounts to the intake manifold.

INTAKE AIR TEMPERATURE SENSOR

The intake air temperature sensor measures the
temperature of the air as it enters the engine. The
sensor supplies one of the inputs the PCM uses
to determine injector pulse width and spark advance.

The intake air temperature sensor threads into the

intake manifold.

--

Intake air

ENGINE <NON-TURBO> Control System

ENGINE COOLANT TEMPERATURE SENSOR

The coolant temperature sensor provides an input

voltage to the power-train control module (PCM).

The PCM determines engine coolant temperature
from the engine coolant temperature sensor.

As coolant temperature varies, the coolant
ture sensor’s resistance changes, resulting in a
ferent input voltage to the PCM.

When the engine is cold, the PCM will demand
slightly richer air-fuel mixtures and higher idle
speeds until normal operating temperatures are

reached.

The engine coolant sensor threads into the water
jacket below the thermostat housing. New sensors

have sealant applied to the threads.

Thermostat

housing

Engine coolant

AFUO066

POSITION SENSOR

The throttle position sensor mounts to the side of the throttle body.