1989 MITSUBISHI GALANT air condition

FUEL SYSTEM -On-Vehicle inspection of MFI Components13-267
INSPECTION
Using Scan tool
Function Item No.
Data display
Data reading
25Sensor detec-tion pressure
HARNESS INSPECTION
Check conditions1 Altitude1 Standard value
lanltion switch: ON1 At 0 m (0 ft.)LrnmmHq
At 600 m(1,969 ft.)710 mmHg
At 1,200 m660 mmHg(3,937 ft.)
At I:800
m610 mmHg
(5,906 ft.)
. Connector:Disconnected
Measure the power supply voltage Ofthe barometric pressure sensor.
connector
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-Engine controlmodule harness
side connector
6%
-

Check for an open-circuit, or a shqrt-circuit to ground, between the enginecontrol module and the barometricpressure sensor.
. Volume air flow sensor connec-tor: Disconnected@--/LA
- Engine control module connec-tor: Disconnected

FUEL SYSTEM - On-Vehicle Inspection of MFI Components13-271
TROUBLESHOOTING HINTS
Hint 1:
The signals of the throttle-position sensor are more
important for control of the automatic transaxle than
for control of the engine; shifting “impact shocks”
are produced if there is a malfunction of the
throttle-position sensor.
INSPECTION
Using Scan tool Hint 2:
If the voltage of the throttle-position sensor deviates
from the standard value, check once again after making the throttle-position sensor adjustment.
in
addition, if there are any indications that the fixedSAS has been moved, adjust the fixed SAS.
Function
Data readingItem No.Data display
14Sensor de-tection vol-
tage
HARNESS INSPECTION
connector
Harness side
connector
Inspection conditionsThrottle valve Standard value
Ignition switch: ON/ To idle position1 450-550
mV
Gradually opening Becomes higher
proportional to
valve opening.
To fully open 4,500-5,500

mV
Measure the power supply voltage of
the TPS.
. Connector: Disconnected
. Ignition switch: ON
Check for continuity of the ground
circuit of the TPS.
. Connector: Disconnected
Repair theharness.
+ K25xz.l-~~IZI)
LZheck for an open-circuit, or a shqrt-Yrcuit to ground, between the er-.--control module and the throttle ~USI-tion sensor.
. Throttle position sensor connec-tnr: Disconnected I
-
- Engine. control module connec-tor: DisconnectedRepair theharness.
u23Bl-m)
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13-274FUEL SYSTEM - On-Vehicle Inspection of MFI Components
CLOSED THROTTLE POSITION SWITCH
MlSYKAEl
Terminal
voltage
Throttle shaft
turning angle Engine control module
1
Throttle position
sensor connector
Component side
connector
Harness side
connector
6FU1355
OPERATION
l
The closed throttle position switch functions to
convert (to HIGH/LOW-level voltage) data as to
whether the accelerator is depressed or re
-
leased, and to input that voltage (as signals) to
the engine control module. The engine control
module, based upon those signals, regulates the
idle air control motor.
TROUBLESHOOTING HINTS
If there is an abnormal condition of the closed throt-
tle position switch switch output even though the results of the checking of the closed throttle posi-
tion switch harness and of the component itself in-
dicate a normal condition, the cause may be pre-
sumed to be one of the following.
lVoltage within the engine control module is ap-
plied, by way of the resistance, to the closed
throttle position switch.
When the foot is taken off the accelerator, the
closed throttle position switch is switched ON,
so the current is grounded.
As a result, the closed throttle .position terminal
voltage changes from HIGH to LOW level.
(1) Improper adjustment of the accelerator cable or
the automatic-cruise-control cable.
(2) Improper adjustment of the closed throttle posi-
tion switch (fixed SAS).
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FUEL SYSTEM - On-Vehicle Inspection of MFI Components13-275
INSPECTION
Using Scan tool
Function
Item No.
Data reading 26
Data displayInspection conditions Throttle valveNormal indication
Switch statusIgnition switch: ONTo idle positionON(Check after pumpingaccelerator several times.)
Slightly openedOFF
HARNESS INSPECTION
71
-
Harness side
Measure the power supply voltage of
the closed throttle position switch.
-. Connector: Disconnected
. Ignition switch: ON
1Voltage (VI
4 or more
ASTOP
Repair theharness.
~@a-Q)
ISENSOR INSPECTION
I(1) Disconnect the throttle position senso_r connector
(2) Check the continuity between terminal QI and body ground.
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Accelerator pedal Continuity
DepressedNon-conductive (m S2)
ReleasedConductive (0 52)
(3) If out of specification, replace the throttle position sensor
assembly.

FUEL SYSTEM - On-Vehicle Inspection of MFI Components13-281
OPERATION
l
The crankshaft position sensor functions to de-
tect the crank angle (position) of each cylinder,
and to convert those data to pulse signals,
which are then input to the engine control mod-
ule. The engine control module, based upon
those signals, calculates the engine rpm, and
also regulates the fuel injection timing and the
ignition timing.
TROUBLESHOOTING HINTS
Hint 1:
If an impact is suddenly felt during driving or the en-
gine suddenly stalls during idling, try shaking the
crankshaft position sensor during idling.
If the engine stalls, the cause may be presumed to
be improper or incomplete contact of the crank-
shaft position sensor’s connector.
Hint 2:
If the crankshaft position sensor output rpm is 0
rpm during cranking when the engine cannot be
started, the cause may be presumed to be a mal-
function of the crankshaft position sensor or a bro-
ken timing belt.
Hint 3:
If the indicated value of the crankshaft position sen-
sor output rpm is 0 rpm during cranking when the
engine cannot be started, the cause may be pre-
INSPECTION
Using Scan tool l
The power for the crankshaft position sensor is
supplied from the ignition switch-IG
and is
grounded to the vehicle body. The crankshaft
position sensor, by intermitting the flow (to
ground) of the 5V voltage applied from the en-
gine control module, produces pulse signals.
sumed to be a failure of the ignition coil’s primary
current to intermittently pulse correctly, so a mal-
function of the ignition system circuitry, the ignition
coil and/or the power transistor is the probable
cause. Hint 4:
If idling is possible even though the crankshaft posi-
tion sensor indicated rpm is a deviation from the
standard value, the cause is usually a malfunction of
something other than the crankshaft position sen-
sor.
Examples:
(1) Malfunction of the coolant-temperature sensor.
(2) Malfunction of the idle air control motor.
(3) Improper adjustment of the standard idling
speed.
Inspection conditions
Description Normal condition
. Engine: CrankingCompare crankingBoth agree.. Tachometer connectionrpm and scan tool(Check intermittent flow ofindicated rpm.ignition coil primary current
by tachometer.)
burn No. / ~i~~~~,,Inspection conditions
At 40°C (104°F)
At 80°C (176°F)
1 ,OOO- 1,250 rpm
650-850 rpm 700-900 mm >
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I

FUEL SYSTEM -On-Vehicle Inspection of MFI Components13-285
AIR CONDITIONING SWITCH AND A/C COMPRESSOR CLUTCH RELAYmt3n7.4al
Jk: L 1 /J l-k~-~+ L!- Air conditioning switch
0
/’
’ ’ -~.i>
‘\ /,
(\ QeF --:
’ -q,,T
(‘a/ A-.,>*/ \
) !I/ ,+f---J;I’,,p
s- / :\,$jy W/’
\mc-- -; --
\\ \\$ &
IF -~1. bI /~-~ i E--z
\ \I i
!
L-,-1&L.- ~~~~.
6FUO845 I
Sub fusible link
‘7 IpI Z%37°GZressor
2 Dual pressure
switch
1
t
Air conditioning OFF
engif’Ie codant* temperatureON switc
h
T
2
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Engine control module
,(65 1\7
v v
Engine control module connector6FU1457
OlLo838
OPERATION
l
The air conditioning switch applies battery vol-
tage to the engine control module when the
air
conditioning 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
.When the air conditioning signals are input, the
engine control module activates the idle air con-
trol motor, and also switches ON the power
transistor. As a result, current flows to the A/C
compressor clutch 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.

13-286FUEL SYSTEM - On-Vehicle Inspection of MFI Components
INSPECTION Using Scan tool
Air conditioning switch
Function Item No.
Data reading 28
Data displayCheck conditionsAir conditioning switchNormal
display
Switch status
. Engine idlingOFF OFF
(The air conditioning
compressor should beONONactivated when the air
conditioning switch is
switched ON.)
Air conditioning compressor clutch relay
Function
Item No.
Data reading 49
Data display
Check conditionsAir conditioning switchNormal display
Air condition-
. Engine: idling afterOFFOFF (Compressor
ing compres-warm up clutch non-
sor clutch
activation)
relay status ON
ONKompressorclutch activation)
HARNESS INSPECTION________ --- -__-. -- ~~-
Measure the power supply voltage of
the air conditioning circuit.
. Engine control module connec-tor: Disconnected- Ignition switch: ON+ Air conditioning switch: ON
side connector
AIR CONDITIONING INSPECTION
Refer to GROUP 55-Air Conditioning.
1 TSB RevisionI

FUEL SYSTEM -On-Vehicle Inspection of MFI Components13-289
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 tempera-
ture sensor decreases when the EGR gas vol-
ume 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.
INSPECTION Using Scan tool
Function Item No.
Data reading
43
Data display 1 Inspection conditions1 Engine condition1 Standard valueI
Sensor. Engine: warm upIdling100°C (212°F) or lower
temoerature* Enaine is maintained in Ia &nstant state for 2
minutes or more
. Remove the vacuum
11 7J$lfifiF~ nr lower 1
hose (green stripes) fromthe EGR solenoid and3,500 rpm150°C (302°F) or higher/hlnn-Turbo>plug both the removed
vacuum hose end and
solenoid valve nipple.
HARNESS INSPECTION
Harness side
connector Measure the power supply voltage.
. Connector: Disconnected
. Ignition switch: ON
Voltage
(V)Repair the
Harness side
connector Check for continuity of the ground
circuit.
. Connector: Disconnected
SENSOR INSPECTION Refer to GROUP
l7-Exhaust Gas Recirculation (EGR) System.
Repair theharness.
@El-IIll. q l)
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