1989 MITSUBISHI GALANT Service Repair Manual

FUEL SYSTEM -On-Vehicule
inspection of MFI Components13-83
AIR CONDITIONING SWITCH AND A/C COMPRESSOR CLUTCH RELAYM13YRAE
Air conditioning switch
Sub fl
FUSC?
Air conditic@compresscclutch relal
Magnetic
clutch
Jsibie li
7
)ningIr /k
!Ik 171 control unitAuto compressor
-
-
)N
Engine control 65moduleA I7
‘1
6FU1411
Engine control module connector
IhJ-Jl r--vrJ=-Jl/l
OlLO838
OPERATION
l
The air conditioning switch applies battery vol-
tage to the engine control module when the air
conditioning is switch is switched ON.
TROUBLESHOOTING HINTS
If the air conditioning compressor’s magnetic clutch
is not activated when the air conditioning switch is
switched ON during idling, it is probable that the l
When the air conditioning signals are input, the
engine control module activates the idle-speed
control motor, and also switches ON the power
transistor.
AS a result, current flows to the
power relay coil and the relay switch is
switched ON, the air conditioning compressor’s
magnetic clutch is activated.
cause is a malfunction of the air conditioning control
system.
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13-84 FUEL SYSTEM - On-Vehicule Inspection of MFI Components
INSPECTION
Using Scan tool
Air conditioning switch
Function Item
No.
Data reading 28 Data display
Check conditions Air conditioning switch
Normal display
Switch status . Engine idling (The air
OFF OFFconditioning com-
pressor should be ac-ON ONtivated when the air
conditioning switch is
switched ON.)
Air conditioning compressor clutch relay
Function
Data reading Item
No. Data display
49Air condition-
ing compres-
sor clutch relay status Check conditions
. Engine: idling after
warm up
HARNESS INSPECTION
Air conditioning switch Normal display
OFFOFF (Compressor
clutch non-activation)
ON ON(Compressor
clutch activation)
,--=+aI_I Engine controlmodule harnessside connector
OlROB13
Measure the power supply voltage of
the air conditioning circuit.
. Engine control module connector: Disconnected
. ignition switch: ON
* Air conditioning switch: ON4
ASTOP
Check the
air condi-
tioning cir-
cuit.
AIR CONDITIONING INSPECTION Refet to GROUP
55-Air conditioning.
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FUEL SYSTEnrll (SOHC-8 VALVE> -On-Vehicule
Inspection of MFI Components13-85
EGR TEMPERATURE SENSOR Ml3Yza
\+\+I connectorComponent side EGR temperaturn r-n~nrrHarness side@
connector 6FlJ1412
1
IwTemperaturelEzlooB
OPERATION
l The EGR temperature sensor functions to con-
vert the data regarding the temperature of the EGR gas downstream from the EGR valve to
voltage, and to input that voltage (as signals) to
the engine control module.
lThe 5V power supply within the engine control
module is supplied, by way of the resistance
within the unit, to the EGR temperature sensor; it passes through the
EGR temperature sensor,
which is a type of resistor, and is grounded at
the engine control module. Note that the resistance of the EGR temperature
6FU1269
sensor decreases when the EGR gas volume
increases and the temperature of the EGR gas
increases.
l The EGR temperature sensor terminal voltage
becomes higher when the resistance of the EGR
temperature sensor increases, and becomes
lower when the resistance decreases.
Consequently, the EGR temperature sensor
terminal voltage varies in accordance with the
temperature of the
EGR gas, becoming lower
when the temperature of the EGR gas in-
creases.
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13-86 FUEL SYSTEM - On-Vehicule inspection of MFI Components
Using Scan tool
FunctionItem No.Data display Inspection conditions Engine condition
Standard value
Data reading 43 Sensor. Engine: warm up
750 rpm (Idling)
70°C or lower
temperature . Engine is maintained in a
constant state for 2 minutes 3,500 rpm
70°C or higher
or more
. Remove the vacuum hose
(green stripes) from the EGR
solenoid and plug both the removed vacuum hose end
and solenoid valve nipple.
HARNESS INSPECTION
Harness sideconnector
@qqJ
I
II
EL -:
f7
Q,
L *A’
-1I01.0523
Measure the power supply voltage.
. Connector: Disconnected
. Ignition switch: ON
Harness sideconnector
Check for continuity of the ground
circuit.
. Connector: Disconnected
SENSOR INSPECTION
Refer to GROUP 17-Exhaust Gas Recirculation (EGR)
System.
-w
STOP
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FUEL SYSTEM - On-Vehicule Inspection of MFI Components13-87
OXYGEN SENSORM13VSAa
/
Oxygen sensor
)G/’ ‘;‘@
i b\A
-
I6FUO659
Theoretical A/F
Component side
Component sideconnectorconnectorIn case of FEDIn case of CALIFI r
Oxygensensor
i klJ
I

-
11 2
Enginecontrol
module
6FU1452
NOTE01 Lo836
l 1 : *2:
OPERATION
l The oxygen sensor functions to
detect th
e
concentration of oxygen in the exhaust gas; it
converts those data to voltage, and inputs the
resulting signals to the engine control module.
l If the air/fuel mixture ratio is richer than the
theoretical air/fuel mixture ratio (i.e., if theconcentration of oxygen in the exhaust gas issparse), a voltage of approximately
1V is output; if the air/fuel mixture ratio in leaner than the
theoretical air/fuel mixture ratio
(Le., if the
concentration is dense), a voltage of approx-
imately OV is output.
l The engine control module, based upon those
signals, regulates the amount of fuel injection SO
that the air/fuel mixture ratio becomes th
e
theoretical air/fuel mixture ratio.
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13-88 FUEL SYSTEM VALVE>- On-Vehicule Inspection of MFI Components
TROUBLESHOOTING HINTS
Hint I’
The exhaust gas purification performance will
Examples:
(1) Malfunction of an injector.
worsen if there is a malfunction of the oxygen sensor. Hint 2:
If the oxygen sensor output voltage deviates from
the standard value even though the results of the
checking of the oxygen sensor are normal, the
cause is probably a malfunction of a component related to mixture control. (2) Air leakage into the intake manifold from a
leaking gasket.
(3) Malfunction of the volume air flow sensor, the intake air temperature sensor, the barometric-
pressure sensor, or the engine coolant tempera-
ture sensor.
Data reading
INSPECTION
Using Scan tool
HARNESS INSPECTION
Data display
Sensor de-
tection vol-
tage Inspection conditions
Engine conditionStandard value
Engine: warm up When sudden decel-
250
mV or lower
(Make the mixture lean eration from 4,000 rpm
by engine speed reduc-
tion, and rich by racing) When engine is sud-
500- 1,000 mV
denly raced
Engine: warm up750 rpm (Idling)
(using the oxygen sen-
sor sianal.
check the air/
400
mV or lower
I I
(changes)
fuel mixture ratio, and600-l ,000 mValso check the condition 2,000 rpm
of control by the engine
control module)
I CALIF@I Hal
FEDHarness
ness
side
connector
Engine control
module harness
side connector
Check for an open-circuit, or a short-circuit to ground between the engine
control module and the oxwen sen-f7 _-
~~SOT.‘-. r$;rdn sensor connector: Drscon-
. Engine control module connector:Disconnected CALIF
Harness side
Check for continuity of the ground
.“‘..“...;;”
Repair theharness.
KEEI-Ground)
1
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FUEL SYSTEM - On-Vehicule inspection of MFI Components13-89
:Federab
:California>
Ea
SENSOR INSPECTION
Caution
1. Before checking, warm up the engine until engine
coolant temperature reaches 85 to 95°C (185 to 205°F).
2. Use an accurate digital voltmeter.
(1) Disconnect the oxygen sensor connector and connect a voltmeter to the oxygen sensor connector.
(2) While repeating engine racing, measure the oxygen sensor
output voltage.
,
IEngineOxygen sensoroutput voltageRemarks
Race0.6-l .OVMake air-fuel mixturerich by acceleratoroperation
NOTE
For removal and installation of the oxygen sensor, refer to
GROUP
15-Exhaust Manifold.
Oxygen sensor installation torque:
40-50 Nm
(30-36 ft.lbs.1
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13-90 FUEL SYSTEM - On-Vehicule Inspection of MFI Components
INJECTORS
Fuel
Connector
Solenoid coil
Plunger
Needle valve -----I
InjectionFilter6FUO514
M13rrAA
Multiport
fuel injection relay
No.1 &j No.2& No.3& No,4+
tI
lFUO642
Engine control module connector
CJ=JW=U-I
0 1 LO636
OPERATION
l The
injectorsare electromagnetic-valve-
equipped injection nozzles that function to inject
fuel based upon injection signals from the
engine control module.
lBecause the surface area of the injection ports is
fixed and because the pressure of the fuel
relative to the pressure within the manifold is
also regulated to a fixed pressure, the amount of
fuel injection by injectors is determined by the
TROUBLESHOOTING HINTS
Hint 1:
If there is a problem with starting while the engine is
warm, perform the combustion test and check for leakage of the injectors.
Hint
2,
If the engine can’t be started, and the injectors are
not activated during cranking, the cause is probably
a malfunction such as described below, not with the
injectors.
(I) Malfunction of the circuit for supply of power to the engine control module, or of the ground cir-
cuit.
(2) Malfunction of the multiport fuel injection relay.
(3) Malfunction of the crankshaft position sensor and/or the camshaft position sensor.
Hint
3.
If there is a cylinder for which the idling condition
does not change when, during idling, the fuel length of time that the needle valve is open, or,
in other words, by the length of time of current
~-
flow to the solenoid coil.
lBattery power supply is supplied, by way of the
multiport fuel injection relay, to the injectors.
When the engine control module switches ON
the power transistor within the unit and current
flows to the solenoid coil, the injectors open and
fuel is injected.
injection of the injectors is cut off in sequence,
check that cylinder as described below.
(1) Check the injector and harness.
(2) Check the spark plugs and the high-tension
cable.
(3) Check the compression pressure. Hint 4:
If the injector activation time deviates from the
standard value even though the results of the
checking of the injector’s harness and of the injector itself are normal, the cause may be pressumed to
be one of the following,
(1) Incomplete combustion within the cylinder. (Malfunction of the spark plugs, the ignition coil,
the compression pressure, etc.)
(2) Incomplete close contact of the EGR valve seat.
(3) Increased engine resistance.
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