MITSUBISHI GALANT 1989 Service Repair Manual

FUEL SYSTEM <SOHC-8 VALVE> -On-Vehicule Inspection of MFI Components13-59
Re
Blu
THROlTLE POSITION SENSOR
SENSOR INSPECTION
(1) Disconnect the throttle position sensor connector, and
connect the special tool (Test harness) between the
disconnected connectors.
(2) Measure the resistance between terminal @ (black clip of
special tool) and terminal @
(red clip) of the connector on
throttle position sensor side.
Standard value: 3.5-6.5
kS2
(3) Measure the resistance between terminal @ (black clip of
special tool) and terminal @
(blue clip).
Open the throttle valve slowly Resistance should vary from
from idle position to fully open approx. 0.5 kQ to 3.5-6.5
kQ
position
smoothly in proportion to
change in throttle valve opening
(4) If the resistance does not conform with specification, or does not vary smoothly, replace the throttle position
sensor.
Throttle position sensor installation torque: 1.5-2.5 Nm (1.1-1.8
ft.lbs.1
<From 1990 models>M13YJAF
Component srde@ connectorThrottle posltlon SensorI
Harness side@ connector
m 1,. I,, .I,, I,, It,
~$-T~ ;I
TerminalvoltageIV1
Engine control module connector
Minimum
Maximum01 LO.0838Throttle shaft turning angle102461
TSB Revision

13-60 FUEL SYSTEM <SOHC-8 VALVE> -On-Vehicule Inspection of MFI Components
OPERATION
TROUBLESHOOTING HINTS
INSPECTION-Using Scan tool
Refer to P.13-57.
HARNESS INSPECTION
Measure the power supply voltage of
the throttle positlon
sensor.
. Connector: Disconnected
. Ignition switch: ON
6FU1241
. Connector: Disconnected
6FU1242
Er’ ”I
miglne controlodule harnessCheck for an open-circuit, or a short-
side connectorcircuit to ground between the engineIcontrol module and the throttle posi-
tion sensor.
19
!!F!=6FU1243
. Throttle position sensor connector: Disconnected0
OK
. Engine control module connector:
Disconnectedr
ASTOP
L
I\:
Throttle posltlon/
sensor connector6FU1244
Repair the
harness.
i
K292Ha)
SENSOR INSPECTION
(1) Disconnect the throttle position sensor connector.
(2) Measure resistance between terminal @ (sensor ground)
and terminal
@ (sensor power).
Standard value: 3.5-6.5
kQ
(3) Connect a pointer type ohmmeter between terminal @
(sensor ground terminal) and terminal
@ (sensor output
terminal).
(4) Operate the throttle valve slowly from the idle position to the full open position and check that the resistanc
e
changes smoothly in proportion with the throttle valve
opening angle.
(5) If the resistance is out of specification, or fails to change smoothly, replace the throttle position sensor.
Throttle position sensor installation torque: 1.5-2.5 Nm (1.1-1.8

ft.lbs.)
TSB Revision

FUEL SYSTEM <SOHC-8 VALVE>- On-Vehicule Inspection of MFI Components13-61
CLOSED THROTTLE POSITION SWITCH <I989 models>MlBYKAE
control -Idle speed control
motor connector
@ Component sideconnector
@ Harness sideconnector
II
ISC plunger
_---__
III*Throttle shaft turning angle
01209
2
-
Engine control module
1
6
3
OFF
aI
ON
-z
Closed throttleDosition switch
lFUO479
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-speed control motor.
TROUBLESHOOTING HINTS
l Voltage 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 switch
terminal voltage changes from HIGH to LOW
level.
If there is an abnormal condition of the closed throt-
tle position switch output even though the results
of the checking of the closed throttle position
switch harness and of the component itself indicate
a normal condition, the cause may be presumed tobe one of the following.
TSB Revision
(1) Improper adjustment of the accelerator cable or the automatic-cruise-control cable.
(2) Improper adjustment of the fixed SAS.

13-62 FUEL SYSTEM <SOHC-8 VALVE> -On-Vehicule Inspection of MFI Components
INSPECTION
Using Scan tool
FunctionItem No.
Data reading 26 Data display
Inspection conditions Switch
status Ignition
switch: ON
(Check after pumping
accelerator several times.) Throttle valve
Normal indication
To idle position
ON
Slightly openedOFF
HARNESS INSPECTION
Harness sideconnector
Y
OlR085
motor connector1 FUO480
Measure the power supply voltage of
the closed throttle position switch.
. Connector: Disconnected
. Ignition switch: ON
IVoltage (V)I
I4 or moreI
Repair theharness.
c@a-m)
SENSOR INSPECTION
(1) Disconnect the idle speed control motor connector.
(2) Check the continuity between terminal
@ and body ground.
TSB Revision
IAccelerator DedalIContinuitvI
DepressedNon-conductive (42)
Released Conductive (0. Q)
(3) If out of specification, replace the idle speed control motor
assembly.

FUEL SYSTEM <SOHC-8 VALVE> -On-Vehicule Inspection of MFI Components13-63
CLOSED THROTTLE POSITION SWITCH <From
1990
models>
Engine control module M13YKAfIdle speed control
motor (Closed throttle
position switch and
idle speed control
motor
cosition sensor)
Idle speed control/ plunger position
Throttle shaft -x-ring angle -
01209
2
Idle speed control motor
position sensor connector
/ c-~ IONrZ
i i ???FT%
;e
’T
A’,-
a
Closed throttleposition switch
/cmgso,l ,“,“,‘;a;;o;ide
6FU1245
OPERATION
TROUBLESHOOTING HINTS
INSPECTION-Using Scan tool
Refer to
P.13-61.
HARNESS INSPECTION
0I
I
@ Harness sideconnector
\
LI
6FU1246
6Fu12a
(2) Check the continuity between terminal @ and body
ground.
Accelerator pedal Continuity
Depressed Non-conductive
(ma)
IReleasedIConductive (0.
Q)1
(3) If out of specification,rep\ace the idle speed corm\ motor
7/assembly.
TSB Revision
Measure the power supply voltage of
the closed throttle position switch.
. Connector: Disconnected
. Ignition switch: ON
SENSOR INSPECTION/
(1) Disconnect the idle speed control motor position sensor connector.
I
II

IS-64 FUEL SYSTEM <SOHC-8 VALVE> -On-Vehicule Inspection of MFI Components
IDLE SPEED CONTROL MOTOR POSITION SENSOR
<I989 models> MIOWAD
@ Component sideIdle speed control motor
connectorposition sensor
l-F---

-
@ Harness side I--
connector
i5EL1402,
4,0
t t
13 A23A17 A14 A24
Enginecontrol
module
: 5v 5v
lFUO514
Fnnirw rnntrol
module connector
Plunger stroke
OlROlOlOlL0838
OPERATION
l The idle speed control motor position sensor functions to convert the data concerning theposition of the plunger (located within the idle-
speed control motor) to voltage, and to input
that voltage (as signals) to the engine control
module. The engine control module, based upon
those signals, then functions to regulate the idle-speed control motor.
l The
5V power supply within the engine control
module is supplied to the idle speed control
position sensor; it then passes through the re-
sistance within the sensor and is grounded at
the engine control module.
TROUBLESHOOTING HINTS
Hint 1’
The idle speed control motor position sensor is the
most important sensor for control of the idling
speed; there is very often a malfunction of this sen-
sor if a problem occurs when the ,engine load is
caused to fluctuate, such as when, during idling, the
air conditioning switch is switched back and forth
between OFF and ON, etc. l
When the plunger located within the idle-speed
control motor extends from its contracted con-
dition, the resistance between the idle speed
control motor position sensor’s variable-resist-
ance terminal and the ground terminal also in-
creases in accordance with that extension. As a
result, the voltage of the idle speed control
motor position sensor’s variable-resistance ter-
minal also becomes higher in accordance with
the extension.
Hint 2:
If the output voltage of the idle speed control motor
position sensor deviates from the standard value
even though the results of the checking of the idle
speed control motor position sensor harness and of
the component itself are normal, the malfunction
may be presumed to be among the following:
TSB Revision1

FUEL SYSTEM <SOHC-8 VALVE>- On-Vehicule Inspection of MFI Components13-65
(1) Improper adjustment of the basic idling speed.
(2) Deposits adhering to the ttirottle valve.
(3) Air being taken into the intake manifold due to a gasket leak, etc.
OPERATION
ISC motor position sensor is a variable resistor type,
and is integrated in the
ISC motor system. The slid-
ing pin of
ISC motor position sensor is in contact
with the end of the plunger. Therefore, as the plun- ger moves, the internal resistance of
ISC motor pos-
ition sensor varies. This leads to the variation of the (4) Improper seating of the EGR valve seat.
(5) lmcomplete combustion within a cylinder. (Mal-
function of spark plugs, ignition coil, injectors,
compression pressure, etc.)
the plunger position of the
ISC motor system, and
sends the signal to ECM. ECM processes the
ISC
motor position sensor signal, idle signal, coolant
temperature signal, load signal (A/T &
A/C) and ve-
hicle speed signal to control the opening angle of
the throttle valve and revolution speed during
en-
output voltage. ISC motor position sensor detects gine idling.
TROUBLESHOOTING HINTS
Since idling is not controlled when ISC motor posi-
tion sensor is troubled, idling may not be evenly
maintained.
INSPECTION
Using Scan tool
FunctionItem No. Data display Inspection conditions Load conditions
Standard value
Data reading 15 Sensor detec-
. Engine coolant tempera-
Air conditioning 500- 1,300 mV
tion voltage
ture: 85-95’C (185-203°F)
switch: OFF
. Lights, cooling fan, electrical accessories: OFF Air conditioning 800-
1,800 mV. Transaxle: neutral (A/T
mod-
switch: ON
els: “P”
range)
1 Closed throttle position Air conditioning900- 1,900 mVswitch: ON (The compressorswitch: ON
clutch must be operating Select lever:
when the air conditioning shift to “D”
switch is ON.)
range.* Engine: running at idle
NOTEThe idle speed control motor position sensor output voltage may be about\
500 mV higher than indicated above when
the vehicle is new [driven approximately 500 km (300 miles) or less].
CautionBefore shifting the select lever to the “D” range, apply the brake\
s to prevent the vehicle from moving forward.
HARNESS INSPECTION
Measure the power supply voltage of
the idle speed control motor position
ei;;;it;;sco$ected
__...._ -.-
TSB Revision

13-66 FUEL SYSTEM <SOHC-8 VALVE> -On-Vehicule Inspection of MFI Components
Harness
sde
connectorI
OlAO362
@ Harness sideconnector
Engine control
module harnessside connector
I-
r
MD9984646FUO666
MD9984646FUo666
A
Check for continuity of the groundcircuit.
. Connector: Disconnected
t
Repair theharness.

l&l)
Check for an open-circuit, or a short-circuit to ground between the engine
control module and the idle speed
control motor position sensor.
* Engine control module connector:f-
A
1
Disconnected
. idle speed control motor position sensor connector: Disconnected Repair the
harness.
~@[z1-8)
I
SENSOR INSPECTION
Disconnect the idle speed control motor position sensor
connector, and connect the special tool (test harness) to
the connector on idle speed control motor position sensor side.
Measure the resistance between terminal
@ (black clip of
special tool) and terminal
0 (white clip) of the idle speed
control motor position sensor connector.
Standard value: 4-6
kS2
(3) Disconnect the idle speed control motor connector.
(4) Connect a
6V DC power supply between terminals 0 and
@ of the idle speed control motor connector to activate
(extend and retract) the idle speed control motor. Measure
the resistance between terminal
@ (black clip of special
tool) and terminal
0 (red clip) of the idle speed control
motor position sensor connector.
Standard value: Smooth increase/decrease in ac-
cordance with extension and retrac-
tion of idle speed control motor
plunger.
Caution
Apply only a 6V DC or lower voltage. Application of
higher voltage could cause locking of the servo gears.
(5) If there is a deviation from the standard value, or if the change is not smooth, replace the idle speed control motor
assembly.
TSB Revision

.-•r12-67FUEL SYSTEM <SOHC-8 VALVE> -On-Vehicule Inspection of MFI Compontl=am - - =
IDLE SPEED CONTROL
MOTOR POSiTiON SENSOR
<From 1990 models> MlOWAE
@ Component sideconnectorIdle speed control mc)tor position sensor
‘{*q-r
T@ Harness sideLconnector
Voltagebetween
@n-@B
1.Plunger strokeI01R0101
I-@=%260jl
En$eecontrol
I3A23
’
A
L7A14 "2
4
I!-
Engine control module connector
6FU1246
01 LO838
OPERATION
TROUBLESHOOTING HINTS INSPECTION-Using Scan tool
Refer to P.13-64.
HARNESS INSPECTIONL
L-J1
@ Harness sideconnector
Measure the power supply voltage of
the idle speed control motor position
sensor.
* Connector: Disconnected- Ignition switch: ON
Check for continuity of the ground
circuit.
. Connector: Disconnected Repair the
harness.
@[zI El
-
m,
[231,
TSB Revision\
Repair the
harness.
K&y-m*

13-68 FUEL SYSTEM <SOHC-8 VALVE> -On-Vehicule Inspection of MFI Components
Engine control
module harness
side connectorCheck for an open-circuit, or a short-circuit to ground, between the enginecontrol module and the idle speedcontrol motor position sensor.
. Engine control module connec-tor: Disconnected. Idle speed control motor positionsensor connector: Disconnected
0
O
K
1
ASTOP
i
Repair theharness.
KzEwDlfl,
!
Idle speed control motor
position sensor connector6FU1252
Idle speed control
motor connector
\A 6FU1253
-
SENSOR INSPECTION
(1) Disconnect the idle speed control motor position sensor
connector.
(2) Measure the resistance between terminals
@ and 0.
Standard value: 4-6 k&2
I) Disconnect the idle speed control motor connector.
.) Connect DC 6V between terminals @ and @ of the idle
speed control motor connector, and then measure the re-
sistance between terminals
@ and @ of the idle speed
control motor position sensor connector when the idle
speed control motor is activated (caused to expand and
contract).
Standard value: Smooth increase/decrease in ac-
cordance with expansion and con-
traction of the idle speed control
motor plunger.
Caution
Apply only a 6V DC or lower voltage. Application of
higher voltage could cause locking of the servo gears.
(5) If there is a deviation from the standard value, or if the change is not smooth, replace the idle speed control motor
assembly.
TSB Revision