Mitsubishi Eclipse. Technical Information Manual (1994) - part 24

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ENGINE <TURBO>   Control System

ACTUATORS AND CONTROL

FAN MOTOR RELAY (RADIATOR AIR CONDITIONING CONDENSER)

This relay controls the radiator fan and air 

control module.

ing 

 fan based on signals from the engine

 

GENERATOR G TERMINAL

N71 

The engine control module limits the generator 
put current by duty control of the continuity between

generator terminal G and the ground.

Trio diode

      - - - - - - - -  

   

     

 

c o i l

.

 

Field

I

coil

I
I I

 

I 

L 

 

Voltage regulator

 

Generator

 terminal voltage: 14.4 V or more

Engine control module

When there is no continuity between generator 

minal G and the ground (let this be 100% duty),

transistor No. 1 

 stays in the always ON state.

When the voltage at generator terminal S reaches

14.4 V, the power transistor is forced to OFF to

adjust the generator output voltage to 14.4 V. This
operation is the same as that of the conventional
generator.

ENGINE <TURBO>   Control System

Voltage regulator

Generator

S terminal voltage: 12.3 V or more

Engine control module

 

When generator terminal G is short-circuited to the
ground (let this be 0% duty), the 

 stays in the

always OFF state. In this case, when the voltage
at generator terminal S reaches 12.3 V, the power

transistor is forced to OFF to adjust the output 
age to 12.3   Since the voltage is lower than
charged battery voltage, practically no current flows
from the generator.

ENGINE 

   Control Svstem

COOLING FAN CONTROL

This sytem is similar to the one introduced on the

1994 

Two transistors inside the engine control module
control the radiator fan and the air conditioning con-
denser fan motor according to the engine coolant
temperature and the vehicle speed. When the air
conditioning switch and air conditioning pressure
switch are ON, the fan motor rotate at high speed

 

regardless of the engine coolant temperature and

vehicle speed.

l

When the engine coolant temperature is faulty,
the fan motors (radiator and condenser) are
driven at high speed.
The engine control module also controls the

fan suitable to the various driving conditions

 cruising, accelerating and decelerating, etc.

Ignition switch

Battery

Radiator

fan motor

relay

Radiator

fan motor

relay

relay

,

(Low speed

transistor)

(High speed

transistor)

ECM

Engine coolant 

 Sensor

.

Throttle position sensor

.

Closed throttle position switch

.

Crankshaft position sensor

.

Vehicle speed sensor

.

Air conditioning switch

.

Air conditioning pressure switch

.

ENGINE <TURBO>   Control System

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GENERATOR CURRENT CONTROL

During the period the engine is in operation, the

engine ECM achieves duty control of the continuity
between generator terminal G and the ground. (In
this case, the OFF duty of terminal G is controlled
to equal the ON duty of the power transistor in the
voltage regulator.)
Operation of the headlights causes a sudden in-
crease in current consumption, but the engine ECM
suppresses a sudden increase in the generator out-
put current, thereby preventing the sudden in-
creases in electric load from abruptly reducing the
engine speed while the engine is running at idle.
(During the period before the generator generates
enough power, the battery current is additionally
supplied to the headlights, etc.) During the period
of approximately 0.5 seconds after the power steer-
ing pressure switch has been set to ON and also
during the period of approximately 0.5 seconds after
the selector lever has been changed over from the

N range to the D range, the engine ECM controls

generator terminal G in terms of 30% OFF duty
to suppress generation of power by the generator.

ECM

Engine coolant temperature sensor

Crankshaft position sensor

D

Air conditioning switch

D

Power steering pressure switch

D

Ignition switch-ST

D

Under the following conditions, however, this control
is not achieved.

l 

High engine speed

l 

Engine coolant ternperature 50°C or lower

l 

Air conditioner 

 ON

l

More than 0.5 seconds after the power steering
pressure switch has been set to ON
More than 0.5 seconds after the selector lever
has been changed over from “N” to “D”

l

Three seconds or less after the engine has been
started

When a high signal at generator terminal FR lasting
for more than 20 seconds is input to the engine

ECM during operation of the engine, the engine
ECM determines that the generator terminal FR

circuit has been open-ciircuited and stores diagnostic
trouble code (No. 

 in memory, and places

generator terminal G   the always OFF state.

Generator G terminal

Generator FR terminal

FR G

Generator

1