display MITSUBISHI GALANT 1989 Service Owner's Manual

On-Vehicle Inspection of MFI
13-158FUEL SYSTEM (SOHC-16 VALVE> - Components
OPERATION
aThe throttle position sensor converts the throttle position opening into a voltage and inputs it to the
engine control module, which
then controls
the
fuel injection, based on the input signal.
l The
5V power in the engine control module is
supplied to the throttle position sensor. It flows
through the resistor in the sensor and is then
grounded in the engine control module.
lAs the throttle valve shaft rotates from the idle position to wide open position, the resistancebetween the variable resistor terminal of the
throttle position sensor and the ground terminal increases. As a result, the voltage at the throttle
position sensor variable resistance terminal also
increases.
INSPECTION
Using Scan Tool TROUBLESHOOTING HINTS
Hint 1: The throttle position sensor signal is more important in the control of automatic trans-
axle than in the engine control. Shifting
shock and other troubles will be caused if
this sensor is faulty.
Hint 2: If the output voltage of the throttle position
sensor is out of specification, adjust the
sensor and check the voltage again.
If there is an evidence of disturbed fixed SAS
setting, adjust the fixed SAS.
Function item No.Data displayCheck conditionThrottle valve Standard value
Data14Sensor Ignition
switch: ON At idle position 300 - 1000 mV
readingvoltage
Open slowlyIncreases with valve
opening
Open widely 4,500
- 5,500 mV
HARNESS INSPECTION
-
i1
@ Harness sideconnector
Check for continuity of the ground
circuit.
l Throttle position sensor connector: Disconnected
Repair the
harness.
(ml-m
3 Harnessside connetor
P
ECMharness sidef connector
Check for an open-circuit, or a short-
circuit to ground between the engine
control module and the throttle posi-
tion sensor.
l Throttle position sensor connector:
Disconnected
l Engine control module connec-
tor: Disconnected Repair the
harness. @El

- El)
(@III-ElII
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FUEL SYSTEM - :::,:k:t?=tiion Of MF’13-163
INSPECTION
Using Scan Tool
Function
( Item No.
Data reading
/ 5
5
l-
+
L
Data display
IAC valve
position step
TCheck condition
l Engine coolant tem- perature: 85 to
95°C
(185 to 203’F)l Lights, electric cool- ing fan, accesso-
ries: OFF
l Transaxle: Neutral
(P range for A/T)
l Closed throttle posi-
tion switch: ON
l Engine: At idle
(Compressor clutch
to be operating in case air conditioning
switch is ON) Load state
Air conditioning switch:
OFF
Air conditioning switch:
Turn from OFF to ON l Air conditioning switch: OFF
l Selector lever: Shift to
D range
,,,,,,,,,I
Increase from 3-40 I
step
NfOTE
In a new vehicle [driven approximately 500 km (300 miles) or less], th\
e IAC valve position sometimes exceeds the
standard value by approximately 20 steps.
Caution
When shifting the selector lever to the
D range, apply brake to prevent the vehicle from moving forward.
HARNESS INSPECTION
IIL\-11 r@Harm ” ’ -conna
tA Engine control
-tmodule harnessside rnnnnctor
Check for open circuit, or short-circuit
to ground, between engine control module and
IAC valve position sensor.
l Engine control module connec- tor: Disconnected
l
IAC valve position sensor connec-
tor. Disconnected
21
@Harness sideconnector
0,OK-& 121
i Repair the
--L
harness
(@lcl- El)
/ ml-~) (@pJ
- @I)
Check for continuity of the ground
circuit.
l
IAC valve position sensor connec-
tor: Disconnected

FUEL SYSTEM (SOHC-16 VALVE> - :::%%t:nspection Of MF’13-169
INSPECTION
Using Scan Tool
i
t
/FunctionItem No. i Data display Check condition Check content
Normal state
Data reading
) 22( Cranking l Engine cranking
speed l Tachometer con-’ Compare cranking speed, Indicated speed to
and scan tool reading agree
netted (check on and ~

I
off of primary current 1
of ignition coil by1
tachometer)
Function 1
Item No. Data display ICheck condition !Check content Normal state
Data reading
i 22 ~
Idle speed l Engine: idling! l Closed throttle posi-
tion switch: ONp i ;;:;;:::;;:;;;
20°C (68°F)1 l,lOO-1,300 rpm
40°C
(I
04°F)950-I ,I 50 rpm
: 80°C (176°F) ~
600-800 rpm
I
Using Oscilloscope
Refer to P.13-74.

On-Vehicle Inspection of MFI
FUEL SYSTEM (SOHC-16 VALVE> - Components13-177
HARNESS INSPECTION
Y
Engine control
module harness
-;side connector
01noee3
AIR CONDITIONING INSPECTION
Refer to GROUP
55-Air Conditioning. Measure the power supply voltage of
the air conditioning circuit.
I
l Air conditioning switch: ON
l Engine control module connec- tor: Disconnected
l Ignition switch: ON
EGR TEMPERATURE SENSOR
GR temperature s
@ Equipment side connector
Check the
air condi-
tioning circuit
EGR temperature sensor71@ Harness sideconnector
i
I*Temperature16210067FU1013
OPERATION
Refer to P.13-85.
INSPECTION
Using Scan tool
Function
Data reading
I
Item No
43
I
Data display
Sensor
temperature
I
Inspection conditions Engine condition Standard value
. Engine: warm up
* Engine is maintained in a . Idle
speed 7o’C (158°F) or lower
constant state for 2 minutes or more 3,500 rpm
70°C (158°F) or higher
* Remove the vacuum
hose (green stripes) from
the EGR solenoid and plug both the removed
vacuum hose end and
solenoid valve nipple.
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13-182FUEL SYSTEM - ~~~;~~~t~pection Of MF’
INSPECTION
Using Scan Tool
Function1 Item
No. ’Data display 1Check conditionI Coolant temperature Standard value
IData reading / 41Drive trme
*’ 1Engine: Cranking0°C (32°F) *2Approx. 20 ms
j: 20°C (68°F)Approx. 40 ms 80°C
(176°F)/ Approx. 9.8 ms
Data reading
NOTE Item
No.
41 i
Data display 1
Check condition
IEngine state 1Standard value
Drive time
*3l Engine coolant temperature: 85 to
95°C (185 to 203°F)
l Lights, electric cooling fan, accesso-ries: OFF
l Transaxle: Neutral
(P range for AIT) Idle
speed
1 2.2-3.4 ms
*‘:The injector drive time refers to when the supply voltage is 11 V and the cranking speed is less than 250 rpm.
*2:When engine coolant temperature is lower than 0°C (32°F). injection is made by four cylinders simultaneously.
*3:When the vehicle is new [within initial operation of about 500 km (300 miles)], the injector drive time may be about
10% longer
Function Item No
.
Drive content Check condition Normal state
Actuator test
01No. 1 injector shut off Engine: Idling afterI Idle state to change further
0
2
No. 2 injector shut off
- warm-up
(becoming less stable or
(Shut off the injectors in stalling)
03li No. 3 injector shut off sequence during after-engine warm-up, check1
I04No. 4 injector shut off
the idling condition)
-k
Imp
4 AL A: Inje,t,r--m--m-Normal waveformdrive time03*0209
(1) Run the engine at idle speed.
(2) Connect the probe to the oscilloscope pick-up point as
shown in the circuit diagram, and check the waveform at
the drive side of each injector.
1
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Using Oscilloscope

13-186On-Vehicle Inspection of MFI
FUEL SYSTEM - Components
IGNITION COIL AND IGNITION POWER TRANSISTOR
-Distributor(built inignition coiland Ignitionpower
transistor)
Equrpment srdeconnector8”
Engine control module connector Spark
plug
Iynitron coil ‘r ,
lgnitron switch (IG,)
Distributor/,@)f1
9 Harness side
connector
4
lgnrtion timingadjustment
connector
7FU0653
Engine control module 9FUOO35
OPERATION Refer to
P.13-96.
INSPECTION Using

Scan Tool
Function
/ Item No.
Data reading
i 44 Data display
iCheck condition jEngine state
Standard value_.-___-- -
-
Ignition
advance
l Engine: Warming up Idle speed
0- 13 “BTDC
l Timing light: Set (set
timing light to check
actual ignition timing)
/--
-
2,000 rpm 19-39 “BTDC
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FUEL SYSTEM - On-Vehicle Inspection of MFI Components13-255
COMPONENTS INSPECTION PROCEDURE-
Using Scan ToolMlsYsAGa
Refer to P.13-41.
POWER SUPPLY AND IGNITION SWITCH-IG
zT=f?Qjkeinjection relay
contrc! qcdule ,6A04,,-
----_OFF/ (IN
t5
’ i
4
-
‘OWE;uppl-
Ignition switch [IG,]
Component
side
connect<
763 66.----
1 6FU1331, )r
Ml3YcAB
Harness
@ side connector
01 LO838
OPERATION
l While the ignition switch is ON, battery power
supply is supplied to the engine control module,
injectors, volume air flow sensor, etc.
l When the ignition switch is switched ON, cur-
rent flows from the ignition switch, via the mul-
tiport
fuel injection relay coil to ground.
INSPECTION
Using Scan tool As a result, the
multiport fuel injection relay
switch is switched ON, and power is supplied,
by way of the multiport fuel injection relay
switch, from the battery to the engine control
module.
Function
Data reading Item No.
Data display Check conditionsStandard value
16
Engine control module power- Ignition switch: O
N
Battery positive voltage
supply voltage
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13-262FUEL SYSTEM - On-Vehicle Inspection of MFI Components
INSPECTION
Using Scan tool
1 Data 12reading
L
Data displayInspection conditions
Sensor de-. Engine coolanttection airtemperature: 85-95°Cvolume (fre-(185-205°F)quency) .Lights, cooling fan, elec-trical accessories: OFF. Transaxle: neutral (PJTmodels: “P” range)
Engine condition
Idling
2,000 rpm
Racing
Standard value 25-50
Hz 30-50 Hz
60-90 Hz 50-80 Hz
Frequency increases 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].
i
Regular waveform03AO203
HARNESS INSPECTION Using Oscilloscope
(1) Run the engine at idle speed.
(2) Connect the probe to the osilloscope
pick-up point as
shown in the circuit diagram, and check the wave form.
Measure the terminal voltage.
. Connector: Disconnected
. Ignition switch: ON
connectorOlMaa
Measure the power supply voltage.
. Connector: Disconnected
. Ignition switch: ON
Harness side
connectorthe multiport fueinjection relay.
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13-264FUEL SYSTEM - On-Vehicle Inspection of MFI Components
OPERATION
l The intake air temperature sensor functions to
convert the temperature of the air (intaken to the
engine) to voltage, and to input that voltage (as
signals) to the eingine control module. The en-
gine control module, based upon those signals,
then corrects the amount of fuel injection, etc.
lThe 5V power supply within the engine control
module is supplied, by way of the resistance
within the unit, to the intake air temperature
sensor; it passes through the intake air temper-
ature sensor, which is a type of resistor, and is
grounded at the engine control module.
Note that the resistance of the intake air
temperaturesensor decreases when the
temperature of the intake air increases.
* The intake air temperature sensor terminal
voltage becomes higher when the resistance of
the intake air temperature sensor increases, and becomes lower when the resistance decreases.
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
Data reading Item No.
13
Data display
Sensor de-
tection
temperature
HARNESS INSPECTION
II
>
7 7
h
I
Check conditions
Ignition switch: ONOr, engine running
Intake air temp.At -20°C (-4°F)
At 0°C (32°F)
At 20°C (68°F)
At 40°C (104°F)
At 80°C (176°F)
Standard value -20°C
0°C
20°C
40°C
80°C
Measure the power supply voltage.
- Connector: Disconnected. Ignition switch: ON
j
/‘“:;~~~v’0OKLl2
Repair theharness.
Cm--a
oE!l-@)
Check for continuity of the glroundcircuit of the intake air temperaturesensor.
. Connector: Disconnected
I
sidevI I 1~ I
I
Harness fi
connector ‘-------i01A051.1
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13-266FUEL SYSTEM - On-vehicle Inspection of MFI Components
BAROMETRIC PRESSURE SENSORMl3VHPYPl
\ Volume air
Barometric
pressure
sensor
Output Voltage
/-4
3
2
1
v 0LzLBarometric pressure mmHg 760 ~~1551
EC1537
(
7
\
‘i
6!
I
I1(
B Volume air flow@ Volume air flowsensor connector sensor connector
5EL1600, L-@I Harness sideconnector@Harness sidernnn~rtnr131 11, I ’““, ,. Iv-.-.,\L4 ,\-5A17 h24
Fnnine 1Anv uI
Barometric pressure sensor
-“J -control
module
I
OllO537
Engine control module connector
01 LOB38
OPERATION
l The barometric-pressure sensor functions to
convert the barometric pressure to voltage, and
to input that voltage (as signals) to the engine
control module.
The engine control module, based upon those
signals, then corrects the amount of fuel injec-
tion, etc.
TROUBLESHOOTING HINTS Hini 1:
If there is a malfunction of the barometric-pressure
sensor,
driveability of the vehicle will become worse
particularly at high altitude.
lThe 5V power supply within the engine control
module is supplied to the barometric-pressure
sensor; it passes through the circuitry within the
sensor, and is grounded at the engine control
module.
lThe barometric-pressure sensor output voltage is sent to the engine control module in propor-
tion to the barometric pressure (absolute pres-
sure).
Hint 2:
If. during high-speed driving, there is a noticeable
sharp drop of the displayed pressure of the
barometric-pressure sensor, check for clogging of
the air cleaner.
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