check engine light MITSUBISHI GALANT 1989 Service User Guide

13-16
FUEL SYSTEM - Troubleshooting
FAILSAFE/BACK-UP FUNCTIONS LIST
If trouble with any major sensor is detected by the on-board diagnostic,\
the vehicle will be kept in the safe
driving conditions according to the preset control logic.
Trouble item Control content for trouble
Volume air flow Fuel injection timing and ignition timing are determined according to th\
e throttle position
sensor sensor
(TPS) and engine revolution speed signal (crankshaft position sensor signal)\
.
Intake air temperature The control is executed with the suction air temperature regarded as
25°C (77°F).
sensor
Throttle position The fuel injection rate is not increased for acceleration according to t\
he throttle position
sensor
(TPS)sensor signal.
Idle speed control After the idle speed control motor plunger is driven and contracted, the\
idle revolution speed
motor position sensor is not controlled.
Engine coolant The control is executed with the engine coolant temperature regarded as \
8OO.C (176°F).temperature sensor (Even if the sensor signal becomes normal again, the control is continued
until the ignltlon
switch is turned off.)
Camshaft position Simultaneous injection of fuel is executed for all cylinders. (In this \
case, the
No.1 cylinder top
sensor dead center is not detected at all after the ignition key is turned on.)\
Barometric pressure The control is executed with the pressure regarded as 760 mmHg
(30
in.Hg).
sensor
Oxygen sensor Closed loop control of the air/fuel mixture ratio is not executed.
i
READ OUT OF DIAGNOSTIC TROUBLE CODE
Precautions for operation
(1) When battery voltage is low, no detection of failure is possible. Be sure to check the battery for voltage and
other conditions before starting the test.
(2) On-board diagnostic item is erased if the battery or the engine control module connector is discon-
nected. Do not disconnect the battery before the di-
agnostic result is completely read.
Using Scan Tool
(1) Switch OFF the ignition switch.
(2) Connect the power-source terminal of the scan tool to the
cigarette lighter socket.
(3) Connect the scan tool to the data link connector. (4) Turn ignition switch to ON.
(5) Using the scan tool, read out and make a note of the
on-
board diagnostic output.
(6) Refer to the diagnostic chart, and repair the indicated loca-
tion of malfunction.
(7) Erase the diagnostic trouble code. (Refer to
P.13-17.)
1 TSB RevisionI

13-32
FUEL SYSTEM - Troubleshooting/Service Adjustment Procedures
FUEL TANK AND FUEL LINEMlBEAAA
Symptom Probable cause Remedy
Engtne malfunctions
Bent or kinked fuel pipe or hose Repair or replace3ue to insufficient fuel
SUPPlYClogged fuel pipe or hoseClean or replace
Clogged fuel filter or in-tank fuel filter Replace
Water in fuel filter Replace the fuel filter or clean the fuel tank
and fuel line
Dirty or rusted fuel tank interior Malfunctioning fuel pump
(Clogged filter in the pump) Clean or replace
Replace
Evaporative emission Mispiping of vapor line
Correct
control system malfunc-
tions (When fuel tank Disconnect vapor line piping joint Correct
filler tube cap is re- moved, pressure releas-
Folded, bent, cracked or clogged vapor line Replace
ng noise is heard) Faulty fuel tank filler tube cap
Malfunctioning fuel tank pressure control
valve Replace
Replace
LL
m ~~ : Paper clip-
F l!;“I /yFp- -
izd--_7-01
A0086SERVICE ADJUSTMENT PROCEDURES
CURB IDLE SPEED INSPECTION
MlBFHAFt
(1) The vehicle should be prepared as follows before the inspection.
lEngine coolant temperature: 85-95°C (185-203°F)
l Lights, electric cooling fan and accessories: OFF
l Transaxle: Neutral
(P for vehicles with an automatic
transaxle)
(2) Connect a tachometer or connect the scan tool to the data
link connector.
NOTE
Refer to
P.13-33 for information concerning connection Of
a tachometer.
(3) Set a timing light in position.
(4) Ground the terminal for adjustment of ignition timing.
(5) Start the engine and let it idle.
(6) Check whether or not the ignition timing is the standard
value; if not, adjust.
Standard value:
5”BTDC + 2”
(7) Stop grounding the terminal for adjustment of ignition timing. .
(8) Let the engine idle for two minutes.
(9) Check the idling rpm.
Curb idle speed:
7502 100 rpm
NOTE
The idling rpm is automatically regulated by the idle-speed control system.
1
TSB Revision

FUEL SYSTEM -Service Adjustment Procedures 13-33
For a female
pin
For a male pin
(insert at side (Insert at lock tab side.,
opposite from lock tab.)
OlLO246
(10)lf not within the standard value range, refer to the CHECK
CHART CLASSIFIED BY PROBLEM SYMPTOMS and check the
MFI component.
BASIC IDLE SPEED ADJUSTMENT
MlBFHBA
(1) The vehicle should be prepared as follows before the inspection and adjustment.
l Engine coolant temperature:
85-95°C (185-205°F)
l Lights, electric cooling fan and accessories: OFF
l Transaxle: Neutral
(P for vehicles with an automatic
transaxle)
(2) Slacken the accelerator cable enough.
(3) Connect the scan tool to the data link connector (white).
(4) If the scan tool is not used, follow the steps below.
@I Insert a paper clip (from the harness side) into the l-pin connector shown in the figure at the left.
Take care not to disconnect the connector.
Caution
The paper clip should be inserted between the
terminals as shown in the figure at the left., @ Connect a primary-voltage-detection type of tacho-
meter to the paper clip.
TSB Revision

FUEL SYSTEM -Service Adjustment Procedures 13-35
(14)Adjust the play of the accelerator cable. (Refer to P.13-
329.)
(15)Connect the idle-speed control motor’s connector.
(16)Adjust the throttle-position sensor.
(17)Start the engine again and let it run at idle speed for about
ten minutes; check to be sure that the idling condition is
normal.
THROTTLE BODY (THROTTLE VALVE AREA)
CLEANING
MllFlCK
(1)Start the engine and warm it up until the temperature of the
engine coolant reaches
80°C (176°F) or higher; then stop
the engine.
(2) Disconnect the air intake hose at the throttle body side.
(3) Spray cleaning liquid (from the intake port of the throttle body) onto the valve, and then leave as is for about fiveminutes.
(4) Start the engine and race it a few times; then let it run at idle speed for about one minute.
NOTE
If the engine idling speed is unstable (or the engine stalls),
let the engine run with the throttle valve slightly open.
(5) If deposits are not removed from the throttle valve, repeat steps (3) and (4).
(6) Connect the air intake hose.
(7) Using the scan tool, erase the diagnostic trouble code, or disconnect the battery’s ground cable for ten seconds orlonger and then reconnect it.
(8) Adjust the basic idle speed (engine speed adjusting screw). (Refer to
P.13-33.)
(9) Adjust the throttle position sensor.
-rottle position ” ynsor connector
(2) If a scan tool is not used, perform the following operation.
< 1989 models> @ Disconnect the throttle position sensor connector and
use the special tool (test harness) between the discon-
nected connector.
r1 TSB Revision
THROTTLE POSITION SENSOR ADJUSTMEiW&
Caution
The adjustment of the throttle-position sensor should be
made after completion of the basic idle-speed adjustment.
(1) Connect the scan tool to the data link connector (white).
,

FUEL SYSTEM - On-Vehicule Inspection of MFI Components13-41
Ciaarette
COMPONENTS INSPECTION PROCEDURE-
USING THE SCAN TOOL
Ml BYBAG
(1) Switch OFF the ignition switch.
(2) Insert the power-supply terminal of the scan tool into the cigarette lighter socket.
lf it is necessary to make the inspection while cranking the
engine, use the battery harness to take power directly from
the battery.
(3) Connect the scan tool to the data link connector.
(4) Switch ON the ignition switch.
(5) Select the vehicle model and the system. l Select by pressing the
m key.
(6) Select the function, and then check the input and outputsignals of the engine control module.If there is an abnormal condition, check the body harness,
the component itself, etc., and repair as necessary.
l Function selection menu
q SELF-DIAG CODE
q DATA LIST
q ACTUATOR TEST
q SPECIAL TEST
l After checking, press the m key.
(7) After making the repair, use the scan tool to recheck, and confirm that the abnormal condition of the input and output
signals has been corrected to the normal condition by the
(9) FrizE’the diagnostic trouble code from the memory.
lUse the scan tool to make the erasure. (Refer to P.13
17.)
lSwitch OFF the ignition switch and disconnect the ground

cab\e from the batteq Ie’tm
a\ for ten seconds

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)
TSB Revision1

FUEL SYSTEM -On-Vehicule
Inspection of MFI Components13-91
INSPECTION
Using Scan tool
FunctionItem No. Data display
Data reading 41
III~~~ion
Inspection conditions Engine coolant temperature Standard value
Engine cranking At
0°C (3~2°F)“~Approx. 21 ms
At
20°C (68°F)Approx. 43 ms
At
80°C (176°F)Approx. 10 ms
FunctionItem No.
Data reading 41
L
Data display
Ac&a$ion
Inspection conditions
. Engine coolant tempera- ture:
85-95°C (185-205°F)* Lights, cooling fan, electric-al accessories: OFF
. Transaxle: neutral
(A/T models: “P” range) Engine condition
Standard value
I
750 rpm (Idling)2.5-4.0 ms
I
NOTE*I: The injector activation time indicates the time under the following con\
ditions: a power source voltage of 11V and a
cranking rpm of 250 rpm or less.
**: Simultaneous injection at four cylinders when engine coolant temperatur\
e is 0°C (32°F).*3: The injector activation time may be about 10% longer than indicated abo\
ve when the vehicle is new [driven approximately 500 km (300 miles) or less].
FunctionItem No.
Actuator test
01
02
03
04
Description
No.
1 injector is shut off.
No. 2 injector is shut off.
No. 3 injector is shut off.
No. 4 injector is shut off. Inspection conditions
Normal indication
Engine: idling after warm The idling condition
changes more.
r”sput off the injectors in(Either becomes more un-sequence during after stable, or engine stalls.)
engine warm-up, check
the idling condition.)
-
I i-. --.-~-db$- A: Injector~__
Normal waveformdrrve time
HARNESS INSPECTION
1
P
Using Oscilloscope
(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.
Measure the power supply voltage of
the injector.
. Connector: Disconnected. Ignition switch: ON
TSB Revision
I
I
4
i1
k ji,v,11
\
YIY’.

13-96 FUEL SYSTEM - On-Vehicule Inspection of MFI Components
IGNITION COIL AND IGNITION POWER TRANSISTOR
ignition coil (IGI)
Ml3WAA
Harness side
@connector0
Harness side
Component side
Distributor\/ 2
4.I_lgnltion. .!
I@LZ)
TachcImetertimingA? I--:*:^^adjustment-_
Lllrnacr
r;rlnI 101 i IG.72 Jl”F
Componenr side
6FU1280
OPERATION
l When the ignition power transistor unit is
switched ON by the signals from the engine
control module, the primary current of the igni-
tion coil will flow. When the ignition power tran-
sistor unit is switched OFF, the primary current
flow is interrupted, and high voltage is produced
at the secondary coil.
l When the engine control module switches OFF
INSPECTION
the power transistor within the unit, the battery
voltage within the unit is applied to the ignition
power transistor unit, and the ignition power
transistor unit is switched ON. In addition, the power transistor unit is switched OFF when the
engine control module switches ON the power
transistor within the unit.
Using Scan tool
1 Function1 Item No.1 Data display / Inspection conditions/ Engine condition 1 Standard value
Data reading 44
Ignition
advance . Engine: warm up
750 rpm (idling)5- 15 “BTDC. Timing light: set(Use the timing light to
check the actual ignition
2,000 rpm 30-40 “BTDCtiming.)
1 TSB Revision

13-106
FUEL SYSTEM - On-Vehicule Inspection of MFI Components
TERMINAL VOLTAGE CHECK CHART
Terminal arrangement of engine control module connector NflTF
01 LO838
. .- -B+: Battery positive voltage
Terminal
No.Check condition (Engine state)StandardvalueRemarksCheck item
103
Backup power supply lgnitron
switch: OFF
102Power supply ignition switch: ONB+
107
109
Fuel pump dnve signal
Engine: Cranking 8V or higher
Engine: Idling
B+I
Ignition switch: ON
Engine:
ldlrng
Ignition switch: ON
Engine: idling
Engine speed: 2,000 rpm
B+I
o-3v
4.5- 5.5v
2.2- 3.2V
56
23
10
Multiport fuel
injection relay
(Fuel pump)
Sensor
rmpressecvoltage
Volume air flow
sensor
Air intake
temperature sensor Ignition
Air intake temperature of
0°C (32°F)switch:ONAir Intake temperature of 20°C (68°F); ji/
Air Intake temperature of 40°C (104°F)1.5-2.1V
Air intake temperature of 80°C (176’F)0.4- 1 .OV
Barometric
pressure sensor
Ignition
Altitude of 0 m (0 ft.)3.7-4.3vswitch:ON Altitude
of 1,200 m (3,937 ft.)3.2-3.av
Engrne coolant lgnitron
Coolant temperature of 0°C (32°F)3.2-3.Wtemperature switch: -sensorONCoolant temperature of 20°C (68°F)2.3-2.9v
1 Coolant temperature of 40°C
(104°F) 1 1.3- 1.9V(
) Coolant temperature of 80°C
(176’F)
1 0.3-0.9V
Throttle posrtionsensor Ignition swatch: It
Set the throttle valve to the
is kept ON for 15
seconds or more
Closed throttle position switchII
I
I
-
Ignition Set the throttle valve to the idlingo-1vswitch:position.3NSlightly open the throttle valve. 4V
or higher
3
16
!O
9
1 TSB Revision1

FUEL SYSTEM -On-Vehicule Inspection of MFI Components13-107
TerminalCheck ItemCheck condition
(Engine state)StandardNo.valueRemarks
22
Camshaft position Engine: Cranking0.2 - 3.ov
sensor
Engrne: ldllng
21Crankshaft position Engine: Crankingsensor
Engine: Idling0.2 - 3.ov
108
104
18
lgnrtron switch-ST Engine: Cranking 8V
or higher
Park/neutral Ignition
Set the selector lever to
P or N.o-3v
position switch switch
:
ONSet the selector lever to D, 2, L or R.8- 14V
Vehicle speed
l Ignition switch: ON
sensor l Slowly run the vehicle forwardkeFaF:hevariation.)
Power steering
pressure switch
;;ir;z;ditioning
Engine:Steering wheel idle state
Idling opera-
tion after
warming-up During steering wheel operation
Engrne:Turn OFF the air conditioning switch.
Idling
Turn ON the air conditioning switch.(The air conditioning compressor is in
the drive state.)
B+
o-3v
o-3v
B+
35
1
51
52
50
51
54
Air conditioning
compressor
clutch relay
Oxygen sensor
No.
1 Injector
No. 2 Injector
No. 3 Injector
No. 4 Injector Ignition power
transistor unit l Engine: Idling
B+ or
l Air conditioning switch: OFF-ON temporarily
(The air conditioning compressor is in the 6V or
higher
drive state.)o’- 3v
Engine: Keep the engine speed at 2,000 rpm
after warming up. kQatot8h2:
(For checking, use a digital voltmeter.) variation.)
Engine: After warming up, rapidly press the
Voltage
accelerator pedal from the idling state. temporarily
drops slightly
from
14V to1 IV.
Engine speed: 3.000 rpm0.3- 3v
Evaporative
emission purge
solenoid ignition switch: ON
Keep the engine speed at 3,000 rpm after the
warmed-up engine is started.B+
o-3v
12Ignition timing
adjustment terminal
ignition
Ground the ignition timing adjustment o- 1vswitch:
terminal.ONRelease the ground of the ignition4.0- 5.W timing
adjustment terminal.
TSB Revision