1989 MITSUBISHI GALANT check engine light

13-10
FUEL SYSTEM - TroubleshootingTerminal
at sensor side
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-.mo .u. m,.0 - rj*> ;; Check engine/malfunction
indicator lamp68AOO93
l
If the voltage (power-supply voltage) supplied to a sensor
is not normal, repair the harness. If the voltage to the sensor is still not normal after the har-
ness has been repaired, repalce the engine control module
and check again.
W&K ENGINE/MALFUNCTION INDICATOR
Among the on-board diagnostic items, a check
engine/mal-
function indicator lamp comes on to notify the driver of the
emission control items when an irregurality is detected. However, when an irregular signal returns to normal
andthe
engine control module judges that it has returned to normal,
the check engine/malfunction indicator lamp goes out. Moreover, when the ignition switch is turned off, the light goes
out. Even if the ignition switch is turned on again, the light does not come on until the irregularity is detected.
Here, immediately after the ignition switch is turn on, the
check engine/malfunction indicator lamp is lit for 5 seconds to indicate that the check engine/malfunction indicator lamp op-
erates normally.
ITEMS INDICATED BY THE CHECK ENGINE/
MALFUNCTION INDICATOR LAMP
1 Enaine control module
IOxvaen sensorI
IVolume air flow sensorIIntake air temperature sensor
Throttle position sensor
Engine coolant temperature sensor
Idle speed control motor position sensor
Crankshaft position sensor
Camshaft position sensor
Barometric rxessure sensor
Injector
Fuel pump
EGR
CHECK ENGINE/MALFUNCTION INDICATOR LAMP
INSPECTION
(1) Check to be sure, when the ignition switch is set to the “ON” position, that the lamp illuminates for about five sec-onds and then switches OFF.
(2) If the lamp does not illuminate, check for damage or dis-
connection of the harness, or for a blown fuse or a failedlight bulb.
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FUEL SYSTEM - Troubleshooting13-13
No.
43
4
-
Diagnostic trouble code
Output signal pattern On-board
diagnostic item Check item (Remedy)
Memory
EGRl Harness and connector
Retainedl EGR valve
l EGR solenoid
L u u u I nnnl EGR valve control vacuum12A0105
Normal -state
-
H
L12A0104I 1
NOTEReplace the engine control module if a diagnostic trouble code is output\
although the inspection reveals that there is no
oroblem
with the check items.
TROUBLESHOOTING TABLE NOTE
*:The failsafe back-up function is in operation.
Diagnostic On-board
trouble diagnostic Diagnostic content
code No.item Major cause
Remarks (trouble
phenomenon, etc.)
-EngineThe engine control module-l Engine stop
control itself is abnormal. l Impossible start
module
11Oxygen Though the air/fuel mixture (1) The oxygen sensor is troubled.
l Deterioration of
sensor ratio closed loop control is (2) Open-circuit, short-circuit or
exhaust gas
operated, the signal voltage of improper connector contactpurifying
the oxygen sensor does not occurs in the oxygen sensorperformance*
vary (to be lean/rich). circuit.
(3) The fuel pressure is improper. l Deterioration of
(4) The injector is troubled. exhaust gas
(5) Air is sucked through the purifying
gasket clearance, etc. performance*
(6) The engine control module is l Abnormal start
troubled. l Unstable idling
l Abnormal
acceleration
12Volume
air flow
sensor Though the engine is running,(I) Volume air flow sensor is
l Abnormal
the signal frequency of the air troubled.acceleration*
flow sensor is
1 OHz or less. (2) Open-circuit, short-circuit or
improper connector contact
occurs in the volume air flow
sensor circuit.
(3) The engine control module is l Unstable idling*
troubled.
13Intake air (1) The signal voltage of the (1) The intake air temperature
l Slightly impropertemperatu-intake air temperaturesensor is troubled.driveability*re sensorsensor is 4.5V or higher.
(2) Open-circuit, short-circuit or l At high
(2) The signal voltage of the improper connector contact
temperatures,
intake air temperature occurs in the air intake
(a) Improper start*
sensor is
0.27V or lower. temperature sensor circuit.
(3) The engine control module is(b) ;J;pe
troubled.
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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.)
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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
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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.
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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.
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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)
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