automatic MITSUBISHI GALANT 1989 Service Owner's Manual

FUEL SYSTEM - On-Vehicle Inspection of MFI Components13-271
TROUBLESHOOTING HINTS
Hint 1:
The signals of the throttle-position sensor are more
important for control of the automatic transaxle than
for control of the engine; shifting “impact shocks”
are produced if there is a malfunction of the
throttle-position sensor.
INSPECTION
Using Scan tool Hint 2:
If the voltage of the throttle-position sensor deviates
from the standard value, check once again after making the throttle-position sensor adjustment.
in
addition, if there are any indications that the fixedSAS has been moved, adjust the fixed SAS.
Function
Data readingItem No.Data display
14Sensor de-tection vol-
tage
HARNESS INSPECTION
connector
Harness side
connector
Inspection conditionsThrottle valve Standard value
Ignition switch: ON/ To idle position1 450-550
mV
Gradually opening Becomes higher
proportional to
valve opening.
To fully open 4,500-5,500

mV
Measure the power supply voltage of
the TPS.
. Connector: Disconnected
. Ignition switch: ON
Check for continuity of the ground
circuit of the TPS.
. Connector: Disconnected
Repair theharness.
+ K25xz.l-~~IZI)
LZheck for an open-circuit, or a shqrt-Yrcuit to ground, between the er-.--control module and the throttle ~USI-tion sensor.
. Throttle position sensor connec-tnr: Disconnected I
-
- Engine. control module connec-tor: DisconnectedRepair theharness.
u23Bl-m)
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13-274FUEL SYSTEM - On-Vehicle Inspection of MFI Components
CLOSED THROTTLE POSITION SWITCH
MlSYKAEl
Terminal
voltage
Throttle shaft
turning angle Engine control module
1
Throttle position
sensor connector
Component side
connector
Harness side
connector
6FU1355
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 air control motor.
TROUBLESHOOTING HINTS
If there is an abnormal condition of the closed throt-
tle position switch switch output even though the results of the checking of the closed throttle posi-
tion switch harness and of the component itself in-
dicate a normal condition, the cause may be pre-
sumed to be one of the following.
lVoltage 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 terminal
voltage changes from HIGH to LOW level.
(1) Improper adjustment of the accelerator cable or
the automatic-cruise-control cable.
(2) Improper adjustment of the closed throttle posi-
tion switch (fixed SAS).
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13-328ENGINE CONTROL - Specifications/Troubleshooting
ENGINE CONTROL
SPECIFICATIONS
SERVICE SPECIFICATIONSM13CB-B
ItemsSpecifications
Standard value
Accelerator cable playmm (in.)
1-2 (.04-,081
3-5 (.12-,201
Accelerator switch switching point
mm (in.)4-8 (.16-,311
TORQUE SPECIFICATIONSMlBCC--B
Items
Accelerator arm bracket to body
Throttle body side inner cable to intake manifold plenum
Accelerator arm side inner cable to body
Nmft.lbs.
8-12 6-
9
4-6 3-4
4-6 3-4
SEALANT
MlOCE--B
Items
Accelerator arm bracket Specified sealant 3M ATD Part No.8663 or equivalent
TROUBLESHOOTING
ACCELERATOR CABLE AND ACCELERATOR PEDAL
MlBEGAB
Symptom
Throttle valve will not fully open or close Probable cause
Remedy
Misadjusted accelerator cable
Adjust
Misadjusted automatic speed-control cable Adjust
Broken return
sprinqReplace
Accelerator pedal
operation not smooth (over acceleration)
Throttle lever malfunction
Accelerator pedal wrongly tightened
Misinstalled accelerator cable
Accelerator cable requires lubrication Replace
Repair
Repair
Lubricate or replace
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13-334AUTO-CRUISE CONTROL SYSTEM - Troubleshooting
TROUBLESHOOTIN
G
MlJEBDH

The auto-cruise control system performs control functions for
the setting or cancellation of the fixed-speed driving speed bas-
ed upon the data provided by input signals. As a result, when
the auto-cruise control system is canceled, the cause of the
cancellation is memorized in a separate circuit by the ECU,
regardless of whether or not the auto-cruise control system
condition is normal or abnormal, thus providing the ECU with
the on-board diagnostic function by certain fixed patterns, as
well as the function of being able to check whether or not the
ECU’s input switches or sensor are normal. Thus, by effectively
using these function, the time required checking and repair can
be shortened.
NOTE
When the computer (ECU) power supply (ignition switch andmain switch) is switched OF-F, the memorized diagnostic
trouble codes are erased, and so for this reason the power
supply must be left ON until the checking is completed.
TROUBLESHOOTING QUICK-REFERENCE CHART
when cancellation not wanted.
be set after an automatic cancellation. ECU: Electronic control unit
After the occurrence of the problem, wasYes. With the main switch ON and the engine
the ignition switch and main switch leftrunning, check the diagnostic trouble code.
ON?+ (P.13-361)
No
Can the auto-cruise control system be set
_r-l;
Yes
No (new normal)Check whether or not, then, the vehicle was driven on a
steep slope, or the SET and RESUME control switches
were operated simultaneously. (The cause is not clear
under the present circumstances.)
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13-336AUTO-CRUISE CONTROL SYSTEM - Troubleshooting
Probable cause1 Check chart No.1 Remedy
l The set vehicle speed variesMalfunction of the ve-No.4Repair the vehicle speec
greatly upward or downward.hicle speed sensor cir-sensor system, or re-l “Hunching” (repeated alternatingcuit place the part.
acceleration and deceleration) oc-
curs after setting is made.
Malfunction of the spee-dometer cable or spee-dometer drive gear
Actuator circuit poor
contact
Malfunction of the ac-
tuator
No.5Repair the actuator sys-tern or replace the part.
Malfunction of the ECU
-Replace the ECU.
The auto-cruise control system is notDamaged or discon-If the input check codeRepair the harness or re
canceled when the brake pedals isnetted wiring of the stopNo.23 indicates a mal- place the stop light
depressed.light switch input circuit; function. No.6-1switch.
brake switch (for auto-
cruise control) malfunc-
tion (short-circuit)
Actuator drive circuit
No.5Repair the harness or reshort-circuit.place the actuator.
Malfunction of the ECU
-Replace the ECU.
-he auto-cruise control system is notDamaged or discon-If the input check codeRepair the harness, or:anceled when the clutch pedal isnetted wiring of clutchNo.23 indicates a mal- repair or replace thedepressed. (vehicles with a manual pedal position switchfunction. No.6-3
clutch pedal position
ransaxle)input circuit switch.
It is canceled, however, when the
)rake pedal is depressed.) Clutch pedal positionswitch improper installa-
tion (won’t switch ON)
Malfunction of the ECU-Replace the ECU.
-he auto-cruise control system is notDamaged or discon-If the input check codeRepair the harness, orzanceled when the shift lever isnetted wiring of park/No.23 indicates a mal- repair or replace thenoved to the “N” position. (vehicles
neutral position switch function. No.6-2park/neutral positionvith an automatic transaxle)input circuit switch.t is canceled, however, when theIrake pedal is depressed.)Improper adjustment of
park/neutral position
switch
Malfunction of the ECU-Replace the ECU.
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AUTO-CRUISE CONTROL SYSTEM - Troubleshooting
13-337
Trouble symptom
Cannot decelerate by using the
SET switch
Probable cause
Check chart No.Remedy
Temporary damagedNo. 2Repair the harness or
or disconnected wir-
replace the SET
ing of SET switchswitch.
Actuator circuit poorNo. 5Repair the harness or
replace the actuator.
Malfunction of the
1 Malfunction of the
ECU
-Replace the ECU.
Cannot accelerate or resume
speed by using the RESUME
switch.
Damaged or discon- No. 3 netted
wiring, or
short-circuit, of
RE-
SUME switch input
circuit Repair the harness or
replace the RESUME
switch.
Actuator circuit poor No. 5iRepair the harness or
; contact replace the actuator.
Malfunction of the
actuator
,
Malfunction of the-Replace the ECU.
ECU
Jute-cruise control system can be i Malfunction of the No. 4
Repair the vehicle-
set while traveling at a vehiclevehicle-speed sensor speed sensor system,
speed of less than 40 km/h (25circuitor replace the part.
nph), or there is no automatic
zancellation at that speed.
Malfunction of the
speedometer cable or
the speedometer
drive gear
Malfunction of the
’ ECU
-Replace the ECU.
The indicator light of the combination Damaged or discon-
neter does not illuminate. netted bulb of
But auto-cruise control system isindicator light
lormal.1
-Repair the harness or
replace the light
bulb.
Harness damaged or
disconnected
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13-340AUTO-CRUISE CONTROL SYSTEM - Troubleshooting
2. CHECKING THE SET SWITCH CIRCUIT
ECU
Description of operation
When the SET switch is switched ON (at the
vehicle speed desired to be maintained, and with
the main switch of the cruise-control switches ON)
that vehicle speed is maintained as a constant
speed.
Furthermore, the constant speed is gradually re- duced
(the “coasting” feature) when the SET switch is pressed and held while the vehicle is
traveling at the previously set constant speed, and,
when the SET switch is released, tne vehicle then
maintains that newly set constant speed (th
e
speed at which the SET switch was
released).
Current flows to the control unit, the cruise control switch (“SET”), and to ground.
Troubleshooting hint
Diagnostic-No.1 5 (automatically cancelled)
ECU terminal voltage
Terminal
No.SignalConditions Terminal voltage
5SET switch
When the SET switch is switched ON ov
When the SET switch is switched OFF
12v
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13-342AUTO-CRUISE CONTROL SYSTEM - Troubleshooting
4. CHECKING THE VEHICLE-SPEED SENSOR CIRCUIT
Combination meter
E-2
Description of operation
The vehicle-speed sensor is installed within the speedometer; it sends to the control unit pulsesignals that are proportional to the rotation speed
(i.e., the vehicle speed) of the transmission’s
output gear. This vehicle-speed sensor is the reed switch type
of sensor; it generates four pulse signals for eachrotation of the speedometer’s driven gear.
Troubleshooting hint
Diagnostic-No.1 2 (automatically cancelled)
ECU terminal voltage Terminal
No.SignalConditions Terminal voltage
15
Vehicle-speed sensor
Move the vehicle forward slowly.
ov -3V or 0.7v
-Flashing-+ higher
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1

13-344AUTO-CRUISE CONTROL SYSTEM - Troubleshooting
Description of operation
* -LimA switch
DC motor
7 coil
-
1. When (with the main switch ON) the driver switches ON the SET switch when the pre-
scribed vehicle speed is reached, the control
unit sends current to the electromagnetic clutch
coil of the actuator, thus attracting the clutch plate, and also illuminating the auto-cruise in-
dicator light, Then, when the ring gear of the planetary pinion is secured, the control motor at
the same time causes the DC motor to be
switched ON, and the DC motor operates at high speed.
2.The rotation of the DC motor is, as described in
the illustration above, transmitted to the worm
gear, and thereafter to the worm wheel, the
sun gear, and the planetary pinion in that
sequence. Because the ring gear is secured at
this time, the planetary pinion rotates while revolving around the sun gear. Because the
planetary pinion is installed to the carrier, both
the carrier and the selecotr drive shaft unified
with it, as well as the selector, are caused to rotate.
3.The switching of the direction (PULL or REL.) of
rotation of the selector is accomplished by reversing the direction of current flow to the
motor, and this is automatically regulated by
the control unit.
4. The current flow to the electromagnetic clutch
is interrupted if the driver switches OFF the
main switch, or if the operation of the auto
cruise control system is
cancelled as a result of
the input of a cancel signal to the control unit because the stop light switch, clutch pedal posi-
tion switch (for a manual transaxle) or the park/ neutral position switch (for an automatic trans-
axle) is activated.
5. As a result of the interruption of current to the
electromagnetic clutch, the clutch plate is
caused to return from the electromagnetic
clutch side to the ring gear side by the force of
the spring, and therefore the ring gear be-
comes free.
6. When the ring gear becomes free, the plane-
tary pinion becomes free relative to the sungear, and thus the selector is caused, by the
return spring installed to the selector part, to
return to its original position.
Troubleshooting hint
Diagnostic-No.1 1 (automatically cancelled)
ECU terminal voltage
Terminal
NO.Signal ConditionsTerminal voltage
8Transistor for electro-When the cruise-control switch (main switch) is switch-
magnetic clutch coiled ON o
v
9DC motor drive (“PULL”
During acceleration by RESUME switch
side) 12v
DC motor drive (“REL.”
During speed reduction (coasting) by SET switch
side)ov
20DC motor drive (“PULL” During acceleration by RESUME switch
side) o
v
DC motor drive (“REL.”
During speed reduction (coasting) by SET switch
side) 12v
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AUTO-CRUISE CONTROL SYSTEM - Troubleshooting13-345
6-1. CHECKING THE STOP LIGHT SWITCH CIRCUIT
Battery
7Tco
A
9%6
I-
(GO) :
To stop light
NOTENC: ON at all timesNO: OFF at all times
Description of operation
When the brake pedal is depressed during
con-
stant-speed travel, the stop light switch’s (NC
)
contacts for the cruise-control system open, with
the result that the current to the electromagnetic
clutch of the actuator is interrupted, thus
cancell-
ing the constant-speed travel.
At the same time, moreover, the closing of the (NO) contacts for the stop light results in the
Troubleshooting hint sending of the cancel signal to the control unit, so
that the actuator’s electromagnetic clutch current is discontinued within the control unit, thereby
canceling the constant-speed travel.
The flow of current is from the battery to fuse N O.
(15) of the junction block, the stop light switch.
and the control unit.
Diagnostic-No.16 (automatically cancelled)
ECU terminal voltage
Terminal
No
.
SignalConditions
3Stop light switch (load
When the brake pedal is depressed
side)
When the brake pedal is not depressed
11Stop light switch (pow-At all times
, er supply side)
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Termianl voltage 12v
ov
12v