set MITSUBISHI GALANT 1989 Service Manual PDF

AUTO-CRUISE CONTROL SYSTEM - Troubleshooting13-353
Trouble symptom
Probable causeCheck chart No.Remedy
Cannot accelerate or resume speed
No.3
by using the RESUME switch. Damaged or discon- netted wiring, or short-
Repair the harness orcircuit, of RESUMEreplace the RESUMEswitch.
switch input circuit
Auto-cruise vacuum
No. 5Repair the harness orpump circuit poor con-replace the auto-cruisetactvacuum pump and
actuator.
Malfunction of the auto-cruise vacuum pump
and actuator (including
air leak from negative
pressure passage)
Malfunction of the ECU-Replace the ECU,
4uto-cruise control system can be Malfunction of theNo.4Repair the vehicle-set while traveling at a vehicle speed vehicle-speed sensorspeed sensor system,3f less than 40 km/h (25 mph), orcircuit‘or replace the part.
there is no automatic cancellation at
that speed.
Malfunction of thespeedometer cable orthe speedometer drivegear
The indicator light of combination
neter does not illuminate. But auto-cruise control system is
iormal.)
Malfunction of the ECU-Replace the ECU.
Damaged or discon--Repair the harness ornetted bulb of indicatorreplace the bulb.light
Harness damaged ordisconnected
vlalfunction of control function by Malfunction of circuit re-No. 9Repair the harness orIN/OFF switchrng of ELC 4 ATlated to accelerator
replace the part.accelerator switchswitch OFF function
Non-operation of torque converter
:lutch, 2nd gear hold, etc.) Malfunction of the ECU
Overdrive is not canceled during Malfunction of circuit re-No. 10Repair the harness or
ixed speed driving. <A/T>lated to overdrive can-replace the part.cellation, or malfunction\lo shift to overdrive during manualIriving.
</VT>of ECU
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13-354AUTO-CRUISE CONTROL SYSTEM - Troubleshooting
CHECK CHART 1. CHECKING THE CONTROL UNIT POWER SUPPLY CIRCUIT
Ignitionswitch<IG,>I
Cruise-control
switchI(8)
pmTzREq
4 atAuto-cruise control unit
13A0377
Description of operation
When the cruise control switch (CRUISE) is switched ON whilethe ignition switch is ON, current flows to the ignition swrtch(IG,), to fuse No.(ll) of the junction block, and to the
cruise-control switch (MAIN switch), the control unit, and to
ground.When the ignition switch is turned OFF, the MAIN switch in thecruise control switch is also turned OFF.
Troubleshooting hint ECU terminal voltage
Terminal SignalConditions TerminalNo.voltage
2Control unitWhen the cruise-Battery
power supply control switch positive
(CRUISE) isvoltage
switched ON.
6. 8Control unitgroundAt all timesov
NOTEl :The connector Nos. in Section “AUTO-CRUISE CONTROL RELATED HARNESSES” and the connector names in the
junction block are represented.
(Applicable on the next page and subsequence.)
2. CHECKING THE SET SWITCH
I
Auto-cruise ’control unitT
v“17 3
A-3SETCrulse-OFFcontrolTONswitch
>: 13
63)
13AO386Description of operation
When the SET switch is switched ON (at the vehicle speed desired to be maintained, and with the CRUISE switch of the
cruise-control switches ON) that vehicle speed is maintained as
a constant speed.
Furthermore, the constant speed is gradually reduced (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, the vehicle thenmaintains that newly set constant speed (the 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.15 (automatically cancelled)
ECU terminal voltage
Terminal SignalConditions TerminalNo.voltage
17SET switch
When the SETovswitch is switchedON.
When the SET
;yv$h is swrtched Battery
positive
voltage
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AUTO-CRUISE CONTROL SYSTEM - Troubleshooting13-355
3. CHECKING THE RESUME SWITCH CIRCUIT
Auto-cruisecontrol unit
--f
Y
Cruise-control
switch
Description of operation
The set speed (before cancellation) resumes when the RE- SUME switch is
swrtched ON, even if the constant-speed
control has been cancelled.That speed will not resume, however, even if the RESUMEswitch is switched ON, if the CRUISE switch is switched OFFand if the vehicle speed decreases to 40 km/h (25 mph) orlower.
In addition, when the RESUME is switched ON and held whi!ethe vehicle is traveling at a constant speed, the vehicle speedwill increase; the speed at which the switch is subsequently released will become the newly set constant speed.
Current flows to the control unit, the cruise control switch
(RESUME), and to ground.
Troubleshooting hint
Diagnostic-No.1 5 (automatically cancelled)
ECU terminal voltage 13AO382
Terminal
Signal ConditionsTermrnalNo.voltage
18RESUME
When the RESUMEOVswrtchswitch is switchedON.
When the RESUME
Batteryswitch is switchedpositiveOFF.voltaae
4. CHECKING THE VEHICLE-SPEED SENSOR CIRCUIT
Auto-cruisecontrol unit
Combinationmeter
Junction
block
(6)
Description of operation
The vehicle-speed sensor is installed within the speedometer; itsends to the controlunit pulse signals that are proportional tothe rotatron speed (i.e., the vehicle speed) of the transaxle’soutput gear.
This vehicle-speed sensor IS the reed switch type of sensor; itgenerates four pulse signals for each rotation of the speedo-
meter’s driven gear.
Troubleshooting hint
Diagnostic-No.12 (automatically cancelled)
ECU terminal voltage
TerminalSignal Conditions
TerminalNo.voltage
19Vehicle-speedMove the vehicleov-0.7vsensorforward slowly.tFlashingJ3V-higher
13A0381
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13-356AUTO-CRUISE CONTROL SYSTEM - Troubleshooting
5. CHECKING THE AUTO-CRUISE CONTROL VACUUM PUMP Description of operation
Hold modeWhen the SET switch is turned ON by the driver turning theCRUISE switch ON when a determined speed is reached, thecontrol unit receives a set signal, and turns the auto-cruisevacuum pump motor ON. After the constant speed is reached,
the motor, control valve and release valve are repeatedly turned
ON and OFF according to driving conditions.
Ignitionswitch <IG,>
Auto-cruise
Acceleration mode
When the RESUME switch is pressed, the control unit receives
a RESUME signal and it not only turns the auto-cruise vacuum
pump motor ON but also turns the control valve and release
(10)
control ’ “”unit13AO376
valve ON (valve is closed)
Deceleration mode
When the SET switch is held down, the control unit receives a
set srgnal and it not only turns the auto-cruise vacuum pumpmotor and control valve OFF (valve is opened) but also turns therelease valve ON (valve IS closed).
Release modeWhen the CRUISE switch is turned OFF, the control unit
receives a cancel signal and it not only turns the auto-cruise
vacuum pump motor OFF but also turns the control valve andrelease valve OFF (valve is opened).
Troubleshooting hint
Diagnostic-No.1 1 (automatically cancelled)
ECU terminal voltage
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AUTO-CRUISE CONTROL
SYSTEM - Troubleshootina13-359
10. CHECKING THE CIRCUITS RELATED TO THE OVERDRIVE-CANCELLATION FUNCTION\
<A/T>
$;c;tly switch
+ c
Overdriveswrtch
4
Auto-cruiseT-kcontrol unitliIV
I
Cruise-control
(14)
m34,:
4 A/T
control
module
13A0379
Description of operation
This is a function that cancels the overdrive function for a
certain fixed period of time, if during constant-speed travel in
overdrive, the actual vehicle speed decreases to less than the
vehicle speed retained in the memory. and then after a short
time causes the vehicle speed to return to the vehicle speed
retained in the memory.
Overdrive is
cancelled under the following conditions.
If, during constant-speed travel, the actual vehicle speed
decreases to 7 km/h (4.4 mph) or more below the set vehiclespeed.Under either of the conditions described above, the overdrive-ON signals output from the microcomputer (with the controlunit) are no longer output, and transistor Tr, is switched OFF.As a result, transistor Tr2 is also switched OFF, causing the
current passing through the overdrive switch of the selector
handle to be interrupted at transistor Tr2. with the result that thedrive is controlled at 3rd gear.
Troubleshooting hint ECU terminal voltage
h I
ITerminalSignalIConditions
TerminalNo.voltaoeI
104 A/T controlWhen the overdriveBatterymoduleswitch is switched positiveON.voltage I
11CIIt;riveWhen the overdrive
Batteryswitch is switchedpositiveON.voltage
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AUTO-CRUISE CONTROL SYSTEM - Troubleshooting13-361
Wi
thscan tool
With voltmeter
Auto-cruise control
\
Data link
connector
III
n
,
/r-I
/Ground161009
Data link
connector
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On-board diagnostic checking is performed when there has
been an automatic cancellation, without cancel switch opera-
tion.
(1) The following two methods can be used for checking the diagnostic. Note that the data link connector is locatedunder the driver’s side instrument panel.
@ If a scan tool is used
Connect the scan tool’s socket and connector to the
cigarette lighter socket and the data link connector, and
set the tester. Use the tester according to its operation
instructions; display the diagnostic trouble code num-
ber and then check.
@ If a voltmeter is used Connect a voltmeter between the ground terminal and
the terminal for auto-cruise control of the data link con-
nector.
It is possible to discover which circuit is the cause of
the cancellation by verifying the indication shown by
the voltmeter with the display patterns shown on the
next page.
(2) When the diagnostic trouble code No. is displayed, check by referring to the check chart applicable to that number.
NOTE
Canceling the diagnostic trouble codes
The diagnostic trouble codes remain in memory until the battery is turned off but they can be canceled in the follo-
wing ways without disconnecting the battery terminals.
@ By turning on the ignition switch.
@ By turning the main switch ON while the SET switch is ON and then, within 1 second, turning the RESUME
switch ON. (Put into condition for input check recep-
tion).
@ By turning ON the SET switch and stop light switch at the same time and continuing the ON condition for 5
seconds or more.
@I By checking that the diagnostic trouble codes are canceled using a scan tool or voltmeter.

13-362AUTO-CRUISE CONTROL SYSTEM - Troubleshooting
DIAGNOSTIC DISPLAY PATTERNS AND TROUBLE CODES Code Display patterns (output codes)
No.(use with voltmeter)
11
xJa-.tu
Probable causeCheck chart No.
Abnormal condition of actuator drive systemNo.5<Electrical type>
Abnormal condition of auto-cruise vacuum
pump drive system <Vacuum type>
1212vAbnormal condition of vehicle-speed signal No. 4systemov/
13"12vLow-speed limiter activation (The system is -normal if it can be reset.) <Electrical type>
ov
14*12v14Automatic cancellation activated by vehicle -speed reduction. (The system is normal if it
ov can be reset.) <Electrical type>
15"12v15Control switch malfunction (when SET and No.2, 3
RESUME switches switched ON simul-
ovtaneously)
16"Cancel switch ON signal input (including inputNo. 6-1, 6-2. 6-3
12v16wirings damage or disconnection, or problemin circuitry within the control unit) <Electrical
ov
we>
Abnormal condition of auto-cruise control unit-
17"12v17Throttle position sensor malfunctionNo. 11
Closed throttle position switch malfunction
ov
NOTE
1. Codes indicated by the * symbol are displayed, if the conditions are satisfied, even if the system is
normal. In either case, the system is normal if it can be reset. If ther\
e is an automatic cancellation not
intentionally made by the driver, however, excluding cancellations explicitly made by the
cancel
procedure, there may be a temporary malfunction such as poor contact of \
a harness connector even
though the system can be reset, and for that reason it is necessary to c\
heck according to each individual check chart that is applicable.
ON
OFF
-
Display when vehicle speed is less thanapproximately 20 km/h (12 mph), or before
the auto-cruise control system is set
0.5 set
++P5 setDiagnostic trouble codes are displayed when, after cancel-
lation of the auto-cruise control system, the vehicle speed
decreases to less than approximately 20 km/h (12 mph),
and are canceled by turning OFF the battery or canceling
the diagnostic trouble codes. (Refer to
P.13-361.) <Va-
cuume type> 03ROlS6
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2.Diagnostic trouble codes are displayed when, after cancel-
lation of the auto-cruise control system, the vehicle speed
decreases to less than approximately 20 km/h (12 mph),
and are erased by switching OFF the ignition switch or the
main switch. <Electrical type>

AUTO-CRUISE CONTROL SYSTEM - Troubleshooting13-363
With scan toolri++, lighter ;
03A0258
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After the diagnostic trouble codes in the memory are
erased, if (when the power supply of the electronic controlunit is switched ON once again) the power supply of the
electronic control unit is normal, the on-board diagnostic
output code display will be as below, regardless of
whether the system condition is normal or not.
@ If a scan tool is used: “NORMAL!!” will be displayed.
@ If a voltmeter is used:Continuous ON/OFF signals will be displayed at 0.5
second intervals.
(Refer to the figure at the left.)
INPUT CHECKING
Input checks should be made when the auto-cruise control
system cannot be set and when it is necessary to check
(when a malfunction related to the auto-cruise
contra! system
occurs) whether or not the input signals are normal.
NOTE
1. If inspection of on-board diagnostic is necessary, confirm diagnostic trouble code first and conduct input check.
2.Input check can be conducted by set operations. On-board
diagnostic terminal outputs display patterns.
3.Display codes are displayed only if the circuit is normal ac-
cording to the conditions shown in the table on the next
paw
WITH SCAN TOOL
(1) The setting of the scan tool is the same as for the on-board diagnostic check.
(2) Turn the ignition switch to ON and switch OFF the main switch.
(3) Select the cruise control system from the scan tool’s menu.
(4) With the set switch ON, switch ON the main switch, and
then, within one second, switch ON the resume switch.
(5) Select the diagnostic trouble code from the scan tool’s
menu.
(6) Perform each input operation according to the input check table (on the next page) and read the codes.
(7) Switch the main switch OFF.
WITH VOLTMETER
(1) The voltmeter is set in the same way as for the on-board diagnostic check.
(2) Turn the ignition switch to ON and switch OFF the main switch.
(3) With the set switch ON, switch ON the main switch, and then, within one second, switch ON the resume switch.
(4) Perform each input operation according to the input check
table (on the next page) and read the codes.
(5) Switch the main switch OFF.

13-364AUTO-CRUISE CONTROL SYSTEM - Troubleshooting
INPUT CHECK TABLE
Code Display patterns (output codes) Input operationCheck resultsNo.(use with voltmeter)
21SET switch ONSmE,: switch circuit nor-
RESUME switch ON RESUME switch circuit
normal
23
<Electrical type> <Electrical type>
Each cancel switch ONEach cancel circuit nor-
1. Stop light switch (brake pedalmal
depressed)<Vacuum type>
2. Clutch pedal position switch(clutch pedal depressed)
St;p light switch nor-
<M/T
>
3. Park/neutral position switch
(shift lever to “N” range)
<A/T
>
<Vacuum type>
Stop light switch ON (brake pedal
depressed)
24
25
n r
Driving at approximately to 40 When both No.4 and
km/h (25 mph) or higherNo.5 can be confirmed,
vehicle-speed sensor
circuit normal.
n r
Driving at less than approximately
to 40 km/h (25 mph) or stopped
26I. Clutch pedal position switchsNJFy;h pedal depressed)
2. Park/Neutral position switch
ON (shift lever to “N” or “P”
range) <A/T>
Clutch pedal positionswitch, park/neutral position switch normal
28Throttle position sensor output
voltage over 1.5V (when the ac-celerator pedal is pressed more
than half way)
$yro;e position sensor
Closed throttle position switch Closed throttle position
OFF (accelerator pedal depressed)switch normal
NOTE1. Each code will be displayed in an order of priority beginning from No\
. 1.If there is no display, it is possible that there is a malfunction of th\
e ECU power-supply circuit or the SET and/orRESUME switch, so check according to check charts 1.2 and 3 (P.13-339,340,341,354,355).2. Continue each input operation until the output code is emitted.If no output codes are emitted for inputs even though the display patter\
n is repeated two or more times, there is amalfunction of the switch sensor.3.When each input operation is performed and the signals for the condition\
s are received by the computer, eachoutput code will be repeatedly displayed in the sequence of priority for\
as long as that signal continues.4.If, during the display of output codes, the input operation is canceled \
(if, for example, the SET switch is set from ONto OFF), the code will be displayed for one cycle of the display, but w\
ill not be displayed during the next cycle.This makes it possible, therefore, to check the OFF condition (existenc\
e of not of a short-circuit of the input line orthe switch).
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AUTO-CRUISE CONTROL SYSTEM - Setice Adjustment ~m~edures13-397
i
ON
y SET
03AO258
03AO258
y SET
CGA0258
(1) Set to the desired speed.
(2) Press the SET button. (3) Check to be sure that deceleration continues while the switch is pressed, and that when it is released the
constant speed at the time when it was released becomes
the driving speed.
NOTE
When the vehicle speed reaches the low limit [approxi- mately 40 km/h (25 mph)] during deceleration, the auto-
matrc speed control will be cancelled.
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SERVICE ADJUSTMENT PROCEDU$$jF
AUTO-CRUISE CONTROL SYSTEM INSPECTION
AUTO-CRUISE CONTROL MAIN SWITCH CHECK
(I) Turn the ignition key to ON.
(2) Check to be sure that the indicator light within the switch
illuminates when the main switch is switched ON.
AUTO-CRUISE CONTROL
SETTING CHECK
(1) Switch ON the main switch.
(2) Drive at the desired speed within the range of approxi-
mately
40-145 km/h (25-90 mph).
(3) Press the SET button.
(4) Check to be sure that the speed is the desired constant speed when the switch is released, and also check to be
sure that the auto cruise indicator light (within the combina-
tion meter) illuminates.
NOTE
<Electrical type>
If the vehicle speed decreases to approximately 20 km/h
(12 mph) below the set speed, because of climbing a hill for
example, the auto-cruise control will be
cancelled.
<Vacuum type>
If the vehicle speed decreases to approximately 15 km/h (9
mph) below the set speed, because of climbing a hill for
example, the auto-cruise control will be
cancelled.
SPEED-INCREASE SETl-ING
CHECK
(1) Set to the desird speed.
(2) Turn the control switch to RESUME position.
(3) Check to be sure that acceleration continues while the switch is hold, and that when it is released the constant
speed at the time when it was released becomes the
driving speed.
NOTE
Even if, during acceleration, the vehicle speed reaches or exceeds the high limit [approximately 145 km/h (90
mph)], acceleration will continue, however, when the
switch is released, the set speed (“memorized speed”) will
become the high limit of the vehicle speed.
SPEED REDUCTION
SEITING CHECK
--