engine MITSUBISHI GALANT 1989 Service Repair Manual

13-166
On-Vehicle Inspection of MFI
FUEL SYSTEM
- Components
INSPECTION
Using Oscilloscope Refer

to P.13-69.
HARNESS INSPECTION
c
IIlFUO633j switch
1218 Harness -.-..-Aside
connectorCheck for continuity of the ground
circuit.
l Crankshaft
position sensor connec-
tor: Disconnected
Ground) lFUO634
I
3:
@ Harnessside connectorfF
68
Engine control
module harness
side connector
J 9P-
l Crankshaft position sensor connec-
tor: Disconnected
9FUOO29 II
Check for open circuit or short circuit
to ground, between camshaft position
sensor and engine control module.
l Engine control module connec- tor: Disconnected
Measure the impressed voltage.
l Crankshaft position sensor connec- tor: Disconnected
l Engine control module connec-
tor: Connected
l ignition switch: ON
Voltage
(V)
4.8 - 5.2 module
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FUEL SYSTEM VALVE> - ::ii,,:::ti=pection Of MF’13-167
CRANKSHAFT POSITION SENSOR
@ Equipment
side connector
Output characteristic (V)
::
L*Time
One rotation of distributor
01R0103
Engine control module connector
@ Harness sideconnector
Enginecontrol
module
Ignition switch (IG,)
IDistributor
Crankshaft position
sensorI/\2
B
/\
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Oscillo
1 I”69 ,.68
I
IL hh5V5v 7FUO653
9FUOO27

13-168FUEL SYSTEM - ::ii$%%spection Of MF’
OPERATION
l The crankshaft position sensor detects thecrank angle (piston position) of each cylinder,
converts it to a pulse signal and inputs it to the
engine control module. The engine control mod- ule computes the engine speed and the intake
air amount for one stroke and outputs the injec-
tor drive signal and injection command signal
based on this signal.
0Power to the crankshaft position sensor is sup-
plied from the ignition switch
(IG), and the
ground is located in the engine control module.
A
5V voltage is applied from the engine control
module to the crankshaft position sensor output
terminal, and the crankshaft position sensor generates a pulse signal as it switches from
OPEN to SHORT (power transistor inside the
sensor switches ON/OFF) between the output
terminal and the ground. TROUBLESHOOTING HINTS
Hint
1: If unexpected shocks are felt during driving or the engine stalls suddenly during idling,
shake the crankshaft position sensor har- ness. if this causes the engine to stall, poor
contact of the sensor connector is sus-
pected.
Hint 2: If the crankshaft position sensor outputs a
pulse signal when the ignition switch is
turned to ON, (without starting the engine),
the crankshaft position sensor or engine control module is probably defective.
Hint 3: If the tachometer reads 0 rpm when the en- gine that has failed to start is cranked, faulty
crankshaft position sensor or broken timing
belt is suspected.
Hint 4: If the tachometer reads 0 rpm when the en- gine that has failed to start is cranked, theprimary current of the ignition coil is not
turned on and off. Therefore, troubles in the ignition circuit and ignition coil or faulty igni-
tion power transistor is suspected.
Hint 5: If the engine can be run at idle even though
the crankshaft position sensor reading is out
of specification, troubles are often in other
than the crankshaft position sensor. [Examples]
(1) Faulty water temperature sensor
(2) Faulty idle air control motor
(3) Poorly adjusted basic idle speed
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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.

13-170FUEL SYSTEM - ::$%:ti=pection Of MF’
HARNESS INSPECTION
III@ HarnessMeasure the power supply voltage.-/-J side connectorl Crankshaft position sensor connec-
tor: Disconnected
l Ignition switch: ON
Voltage
(VI
Repair the
hahrness
(@a - Igni-
B+tion switch)
or check the
ignition
lFUO633 !switch
1 FU0634
side connectorside connector
Engine control module
Engine control moduleharness side connect01harness side connect01
9FUOO30
Check for continuity of the ground
circuit.
l Crankshaft position sensor connec- tor: Disconnected
1 Repair th
e
Check for open circuit, or short-circuit
to ground, between crankshaft posi-
tion sensor and engine control mod-
ule.
l Engine control module connec-
tor: Disconnected
l Crankshaft position sensor connec-
tor: Disconnected ~
Repair the
+ harness
/ @El-El)
*
lFUO637
Measure the impressed voltage.
l Crankshaft position sensor connec- tor: Disconnected
l Engine control module connec-
tor: Connected
l Ignition switch: ON
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On-Vehicle Inspection of MFI
FUEL SYSTEM (SOHC-16 VALVE> - Components13-171
IGNITION SWITCH-ST Ignition switch (ST)
Engine control module connector T
-nEngine control module5171
OPERATION INSPECTION
Using Scan Tool
Refer to
P.13-77. 7FUO653
6FU1267
HARNESS INSPECTION
Engine control
module harnessMeasure the input voltage to theside connectorengine control module.
l Engine control module connec-
tor: Disconnected
l Ignition
switch: START
harness
(j?iJ - lgnitiol
switch) or
check the
ignition
6FUl258switch/
module harnesside connector
l Engine control module connec-
tor: Disconnected
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13-172
On-Vehicle inspection of MFI
FUEL SYSTEM
- Components
IGNITION SWITCH-ST AND PARK/NEUTRAL POSITION SWITCH
Ignition switch (ST)
-T-@ k&pe;grt side
Starter Sterminalf
8
I 7FUO653
Engine control module
0~~~2~5
Engine control module connector
OPERATION
TROUBLESHOOTING HINTS INSPECTION
Using Scan Tool
Refer to
P.13-78.
HARNESS INSPECTION
r
I!-@ Harnessside connector
II1Measure the power supply voltage of
B o
4’
_j
F---l
the park/neutral position switch.-
0
Il Engine control module connec-
tor: DisconnectedI
l Park/neutral position switch con-0/
r
I nectar:
Disconnected
I l Ignition switch: START
Voltage
(V)
he 9FUO266
~

/B+
IiEngine control
module harness
9 HarnessIFside connector
Check for continuity between park/
neutral position switch and engine
control module.
l Engine control module connec- tor: Disconnected
l Park/neutral position switch con- nector: Disconnected
NOTE
Touch the circuit tester probes to
both ends of the harness
9~~0267
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cl OK
/ Repair the
-I, harness
j ml-m

FUEL SYSTEM - ::i%%?ction Of MF’13-173
r
srde connector
nectar:
Disconnected
l Ignition switch: ON
PARK/NEUTRAL POSITION SWITCH INSPECTION
Refer to GROUP 23-Troubleshooting.
VEHICLE SPEED SENSOR
Vehicle speed sensor
Vehicle speed sensor
WI
rerminal(oltage Frequency
[Hz1
MIBYQAA
Component side@ connector
Engine control module connector 6FU1410
1.
/
Vehicle speed [km/h (mph)]
16245

1
OlLO838
OPERATION TROUBLESHOOTING HINTSRefer to
P.13-80.
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13-174FUEL SYSTEM - :::;:%t~pection Of MF’
HARNESS INSPECTION
Engine control module
harness side connectorCheck the vehicle speed
sensor-output circuit for continuity.
l Engine control module connec-
tar! Disconnected
l Move the vehicle.
Engine controlmodule harness
side connector
66
r,‘=6FUl778
Check for open circuit or short-circuit
to ground, between engine controlmodule and vehicle speed sensor.
l Engine control module connec- tor: Disconnected
l Vehicle speed sensor connector: Disconnected Repair the
harness
@El - 8)
Check for continuity of the ground
speed sensor:
Discon-
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6FU1465 /
Measure the impressed voltage.
l Vehicle speed sensor connector: Disconnected
lEngine control module connec-
SENSOR INSPECTION Refer to GROUP
54-Meters and Gauges.

On-Vehicle Inspection of MFI
FUEL SYSTEM - Components
POWER STEERING PRESSURE SWITCH13475
700 - 2,000 (7
- 20,;i~~*~2,000
100 - 284)213- 164)
Pressure
fkPa (kg/on?*. psi11
Enaine control module connector
Enginecontrol
module
Power steering
pressure switch
@ Harness side connector
IIll
7FUO536
I
OPERATION
INSPECTION
Using Scan Tool Refer
to
P.13-82.
7Fuo653
HARNESS INSPECTION
side connector
Engine control
module harness
side connector
I
7FU1235Check for open circuit or short-circuit
to ground, between engine control module and power steering pressure
switch.
l Power steerina messure
switch
connector: Disconnected
l Engine control module connec-
tor: Disconnected
I
Repair the
harness
(@m -11071)
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