Mitsubishi Eclipse Workshop Manual page 76

13-12
FUEL
-
Troubleshooting
Trouble
:ode
No.
Diagnosis
rtem
Diagnosis content
Major
cause
Remarks (trouble
phenomenon,
etc.!
Engine
control unit
The engine control unit itself is
abnormal.
r
Engine stop
o
lmpossible start
1t
Oxygen
sensor
Though the airlfuel
mixture
ratio feed-back control
(closed
loop control) is
operated. the
signal
rcltage of the onßen
sensor
does not vary (to
be
lean/rich).
(1) The
oxlgen sensor
is troubled.
(2) Open-circuit short-circuit or
improper connector contact
ogculs
in the
oxygen sensor
crrcu[.
o
Deterioration
of
exhaust
gas purifying
performance'
(3)The fuel
pressure is
improper.
(4)
The injector
is troubled.
(5)Ar
is
sucked through the gasket
clearance.
etc.
(6) The
engine
control unit
is
troubled.
o
Deterioration of
exhaust
gas purifoing
performance'
.
Abnormal
start
.
Unstable idling
.
Abnormal
acceleration
12
Air flow
sensor
Though the engine is running,
the signal frequency
of the
air
flow
sensor
is
10Hz
or
less.
(1) Air
flow
sensor is
troubled.
(2) Open-circuit short-circuit or
improper connector contact
occurs
in the air
florru sensor
circuit.
(3) The
engine control unit
is
troubled.
.
Abnormal
acceleration'
.
Unstable
idling'
r3
Intake air
temperature
sensor
(1) The signal
voltage of the
intake air
temperature
sensor
is
4.5V or
higher.
(2) The signal roltage of
the
intake air temperature
sensor
is
0.27V or loler.
(l)
The
intake air
temperature sensor
is troubled.
(2) Open-circuit short-circuit
or
tmproper connector contact
occurs
in the air
intake
temperature sensor circuit.
(3)
The engine control unit
is
troubled.
o
Slightly
improper
drireabiliV
o At
high
temperatures.
(a) lmproper start'
(b)
Unstable
idling'
14
Throttle
position
sensor
(1)
The signal lroltage of
the
thronle position
sensor is
0.2V or
lorarer.
(2) Though
the idle position
switch is on. the
signal
voltage
of the throttle
position sensor
is 2V or
higher.
(1) The throttle position
sensor
is
troubled or improperly
adiusted.
(2)
Open-circuit shorl-circuit or
improper connector contact
occurs
in the throttle
position
sensor circuit.
o
SlightV improper
drireability
.
Engine stop
(3) The idle position
sruitch ON is
troubled.
(41
The idle position
sruitch signal
line is
short-circuited.
(5) The
engine control unit
is
troubled.
o
Engine stop
o
Racing
is
impossible
21 Engine
coolant
temperature
sensor
(1) The signal
roltage of
the
engine coolant
temperature
sensor
is 4.6V or
higher.
(2) The signal
rohage of
the
engine coolant
temperature
sensor
is 0.11V or lol,er.
(3) During
engine warming-up,
the engine coolant
temperature sensor signal
indicates that the
engine
coolant
temp€rature
drops.
(11
The engine coolant temperature
sensor is troubled.
(2)
Open+ircuit shoft-circuit or
improper connector contact
occurs
in the engine coolant
temperature sensor circuit.
(3) The
engine control unit
is
troubled.
During cold
weather.
o
Starting
is
impossible.'
o
Unstable
idling'
.
lmproper
acceleralion'
TROUBLESHOOTING TABLE
NOTE
'
:
The failsafe,/back-up function is in
operation.
C
o
@Mißubasha
MotorgCorporataon
Ap3. 1991
PWUE90I0