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.