1989 MITSUBISHI GALANT air condition

FUEL SYSTEM - On-Vehicule Inspection of MFI Components 13-47
OPERATION
l
Activates the fuel pump during engine cranking
and while the engine is running.
l When the ignition switch is set to the START
position, current flows, by way of the
multiport
fuel injection relay coil, from the ignition switch
to ground. As a result, the
multiport fuel injec-
tion relay switch is switched ON, and the power
for activation of the fuel pump is supplied, by
way of the
multiport fuel injection relay switch,
from the battery to the fuel pump.
INSPECTION
Using Scan tool
l While the engine is running, the engine control
module switches ON the power transistor, after
which current flows to the
multiport fuel injec-
tion relay coil, and the power for activation of
the fuel pump is supplied to the fuel pump.
l When the
multiport fuel injection relay switch is
switched ON, battery voltage is also applied to
the engine control module, and so the engine
control module detects the fact that the power
for activation of the fuel pump is being supplied
to the fuel pump.
Function Item
No.
Actuation Inspection conditions DescriptionNormal condition
Actuator test 07 Actuates fuel
. Engine cranking Hold the return hosePulsation can be felt.
pump, clrcu-
. Fuel pump forced between two fingers
lating fuel. activation
so as to feel the
The inspection pulsation of the
flow-should be conducteding of fuel.
for both of the above conditions. Listen to the pump
Pump sound can besound at a place nearheard.the fuel tank.
Check for continuity of the ground
circuit.
I
. ;E;;,, pumpconnector: Discon-
2
1
Y-
!
Repair theharness.
@El- @ HarnessGround)connector
O~AOZOl3
I
Check for continuity between the fuel
pump and the checking terminal.
connector: Discon-
1
@uide 1
B
0. ;;;;,,
pump
L
Check the fuel pump.
. Apply battery voltage to the check-
ing terminal and operate the pump.
!I:7
OK
connector :1 = 6FUl238
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13-50 FUEL SYSTEM - On-Vehicule Inspection of MFI Components
INSPECTION
Using Scan Tool
Item No. Data display Inspection conditions
12Sensor de-
tection air
volume (fre-
quency) . Engine coolant
temperature: 85-95°C(185-205°F). Lights, cooling fan, elec-
trical accessories: OFF
. Transaxle: neutral (iVT
models: “P” range)
RacingFrequency in-
creases as racing
rpm increases.
NOTEThe volume air flow sensor output frequency may be about 10% higher than\
indicated above when the vehicle is new [driven approximately 500 km (300 miles) or less].
Regular waveform 03A0203
HARNESS INSPECTION
@
Harness sideconnector
6
0-0
~
0
=
Using Oscilloscope
(1) Run the engine at idle speed.
(2) Connect the probe to the
osilloscope pick-up point a
s
shown in the circuit diagram, and check the wave form.
Measure the power supply voltage.
. Connector: Disconnected
. Ignition switch: ON
--P
IRepair the
Harness sideconnector
Measure the terminal voltage.
. Connector: Disconnected
. Ignition switch: ON ~

0
OK’ 30
Repair the
harness
.
cm-an)
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13-52 FUEL SYSTEM - On-Vehicule Inspection of MFI Components
Consequently, the intake air temperature sensor
terminal voltage varies in accordance with the
temperature of the intake air, becoming lower
when the temperature of the intake air in-
creases. TROUBLESHOOTING HINTS
Because the intake air temperature sensor detects
the temperature of the intake air in the air cleaner, it
indicates a temperature different than the
tempera-
ture of the outside air when the engine is running.
INSPECTION
Using Scan tool
Function Item
No.
Data reading 13 Data display
Sensor de-tectlontemperature
connector
-,-S=
[
a
ry:
EQO
n
OlRO262
Check conditions
Ignition switch: ON
Or, engine running Intake air temp.
At
-20°C (-4°F)
At 0°C (32°F)
Standard value -20°C
0°C
IAt60~) I 80°CI
HARNESS INSPECTION
I
@ Harness sideconnector 8 0-0
Jill
I54
T
Volume air flowsensor side connector
Check for continuity of the ground
circuit.
. Connector: Disconnected
/-
/OKcl2
--/
Repair theharness.
@El-lT$lH)
IMeasure the power supply voltage.
Connector: Disconnected Ignition
switch: ON
IASTOPVoltage (V)
1 4.5-4.9 1
SENSOR INSPECTION
(1) Disconnect the volume air flow sensor connectors.
(2) Measure resistance between terminals @
and
@.
6FUO622
Temperature “C (“F)
0(32)
20(68)
80 (176)
Resistance (kS2)
6.0
2.7
0.4A
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13-54 FUEL SYSTEM - On-Vehicule Inspection of MFI Components
TROUBLESHOOTING HINTS Hint 1: Hint 2:
If there is a malfunction of the barometric-pressure If, during high-speed driving, there is a noticeable
sensor,
driveability of the vehicle will become worse sharp drop of the displayed pressure of th
e
barometric-rxessure sensor, check for clogging ofparticularly at hig’h altitude

.
the air cleaner.
INSPECTION Using Scan tool
AltitudeStandard valueICheck conditions
Item No. Data display
25Sensor detec-
tion pressure
Function
Data reading
Ignition switch: ON
At 0 m (0 ft.) 760 mmHg
At 600
m(1,969ft.j710 mmHg
I
At 1,200 m660
mmHg(3,937
ft.)
At 1,800
m(5,906 ft.) 610 mmHgI
HARNESS INSPECTION
Check for continuity of the ground
circuit.
. Connector: Disconnected
connector
L,?
la
Fi
gg-CI
e
Repair the
harness.
KBEil-IBHZI)
Measure the power supply voltage of
the barometric oressure
sensor.
. Connector: Disconnected
. Ignition switch: ON
Harness side
connector
Check for an open-circuit or a short-circuit to ground between the engine
control module and the barometric pressure sensor.
f Volume air flow sensor connector: Disconnected
Engine control
module harness
@ Harness sideside connector
Engine control module connec-
tor: Disconnected Repair the
harness.
ozsEl-~)
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13-56 FUEL SYSTEM - On-Vehicule Inspection of MFI Components
INSPECTION
Using Scan tool
FunctionItem No.
Data reading
-*LI
Data display
Sensor de-
tection
temperature
HARNESS INSPECTION
connector OlLO461Check conditions
Ignition switch: ON
Or, engine running Coolant temperature
Standard value
At
-20°C (-4°F)-20°C
At 0°C (32°F)0°C I
At
20°C (68°F)20°C
connector - Ic
OIL0463L
-16R1251
Temperature “C (“F)Resistance (kS2)
0 (32)5.9
20 (68)2.5
40 (104)1.1
80 (176) 0.3
(3) If the resistance deviates from the standard value greatly
replace the sensor.
J
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At 40°C (104°F)40°C
At 80°C (176°F)80°C
1
Check for continuity of the ground
circuit.
. Connector: Disconnected
Repair the
harness.
b&XII-@.
lm
Measure the power supply voltage.I. Connector: Disconnected
Ignition switch: ONVoltage
(VI
SENSOR INSPECTION
(1) Remove engine coolant temperature’ sensor from the
intake manifold.
(2) With temperature sensing portion of engine coolan
t
temperature sensor immersed in hot water check resist-
ance.

13-58 FUEL SYSTEM -On-Vehicule Inspection of MFI Components
TROUBLESHOOTING HINTS
Hint 1:Hint 2:
The signals of the throttle-position sensor are more If the voltage of the throttle-position sensor deviates
important for control of the automatic transaxle than from the standard value, check once again after
for control of the engine; shifting “impact shocks” making the throttle-position sensor adjustment.
are produced if there is a malfunction of the
throttle-position sensor.
INSPECTION
Using Scan tool
Function/ Item No.1 Data display 1 Inspection conditions1 Throttle valve1 Standard value
Data reading 14 Sensor
vol-tageIgnition switch: ON held
for 15 sec. or more
HARNESS INSPECTION
E q-0
JJ ~
@ Harness side0
connector
@ Harness sideconnector
Harness side
connector
Measure the power supply voltage of
the throttle position sensor.
. Connector:’ Disconnected
. Ignition switch: ON
Check for continuity of the ground
circuit.
Connector: Disconnected
Repair the
harness.
bZilZl-m* &I)
Check for an open-circuit, or a short-
circuit to ground, between the engine
control module and the throttle posi-
. Throttle position sensor connector: Engine control module connector:
Disconnected Repair the
harness.
Fi&TUI-mj
01103611
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13-62 FUEL SYSTEM -On-Vehicule Inspection of MFI Components
INSPECTION
Using Scan tool
FunctionItem No.
Data reading 26 Data display
Inspection conditions Switch
status Ignition
switch: ON
(Check after pumping
accelerator several times.) Throttle valve
Normal indication
To idle position
ON
Slightly openedOFF
HARNESS INSPECTION
Harness sideconnector
Y
OlR085
motor connector1 FUO480
Measure the power supply voltage of
the closed throttle position switch.
. Connector: Disconnected
. Ignition switch: ON
IVoltage (V)I
I4 or moreI
Repair theharness.
c@a-m)
SENSOR INSPECTION
(1) Disconnect the idle speed control motor connector.
(2) Check the continuity between terminal
@ and body ground.
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IAccelerator DedalIContinuitvI
DepressedNon-conductive (42)
Released Conductive (0. Q)
(3) If out of specification, replace the idle speed control motor
assembly.

IS-64 FUEL SYSTEM -On-Vehicule Inspection of MFI Components
IDLE SPEED CONTROL MOTOR POSITION SENSOR
MIOWAD
@ Component sideIdle speed control motor
connectorposition sensor
l-F---

-
@ Harness side I--
connector
i5EL1402,
4,0
t t
13 A23A17 A14 A24
Enginecontrol
module
: 5v 5v
lFUO514
Fnnirw rnntrol
module connector
Plunger stroke
OlROlOlOlL0838
OPERATION
l The idle speed control motor position sensor functions to convert the data concerning theposition of the plunger (located within the idle-
speed control motor) to voltage, and to input
that voltage (as signals) to the engine control
module. The engine control module, based upon
those signals, then functions to regulate the idle-speed control motor.
l The
5V power supply within the engine control
module is supplied to the idle speed control
position sensor; it then passes through the re-
sistance within the sensor and is grounded at
the engine control module.
TROUBLESHOOTING HINTS
Hint 1’
The idle speed control motor position sensor is the
most important sensor for control of the idling
speed; there is very often a malfunction of this sen-
sor if a problem occurs when the ,engine load is
caused to fluctuate, such as when, during idling, the
air conditioning switch is switched back and forth
between OFF and ON, etc. l
When the plunger located within the idle-speed
control motor extends from its contracted con-
dition, the resistance between the idle speed
control motor position sensor’s variable-resist-
ance terminal and the ground terminal also in-
creases in accordance with that extension. As a
result, the voltage of the idle speed control
motor position sensor’s variable-resistance ter-
minal also becomes higher in accordance with
the extension.
Hint 2:
If the output voltage of the idle speed control motor
position sensor deviates from the standard value
even though the results of the checking of the idle
speed control motor position sensor harness and of
the component itself are normal, the malfunction
may be presumed to be among the following:
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