1991 MITSUBISHI 3000GT brake

13-162CRUISE CONTROL SYSTEM - Troubleshooting
Trouble symptomProbable causeCheck chart No.
Remedy
Cannot accelerate or resume speedOpen or short circuit in
No. 2by using the RESUME switch.RESUME switch circuit inReplace the control switch
control switch
Vacuum pump assemblyNo. 5circuit poor contactRepair the harness or
replace the vacuum pump
Malfunction of thevacuum pump assembly
(including air leaks
from negative pressurepassage)assembly.
Malfunction of the ECU-Replace the ECU.
Even when CANCEL switch is set toON, cruise control is not canceled
Open or short circuit
in CANCEL switchIf the input check
Replace the control switch
(Cruise control, however, iscode No. 27 indicatescircuit in control switch
canceled when brake pedal isa malfunction.
depressed.)No. 2
Malfunction of the ECU-Replace the ECU
The cruise control system can be set
Malfunction of theNo. 4while traveling at a vehicle speedvehicle-speed sensorRepair the vehicle speed
of less than 40 km/h (25 mph), or
circuitsensor system, or replace
there is no automatic cancellationthe part.
at that speed.Malfunction of thespeedometer cable orthe speedometer drive
gear
Malfunction of the ECU
-Replace the ECU.
The cruise control indicator light
No. 3
of the combination meter does notDamaged or disconnectedbulb of indicator lightRepair the harness or
illuminate. (But cruise controlreplace the light bulb.
system is normal)Harness damaged or
disconnected
Malfunction of the ECU
-Replace the ECU.
Cruise control ON indicator light
No. 3
does not come on. (However, cruiseBurned-out indicator lightbulbRepair the harness or
control is functional.)replace the main switch.
Open or short circuit in
harness
Malfunction of control functionby
ON/OFF switching of ELC 4 AA
accelerator switch.
(Non-operation of damper clutch,
2nd gear hold, etc.)
Overdrive is not canceled during
fixed speed driving
No shift to overdrive during
manual driving.
Malfunction of circuitrelated to acceleratorswitch OFF function
Malfunction of the ECU
Malfunction of circuit
related to overdrive
cancellation, or mal-
function of ECU
No. IO
No. 11Repair the harness or
replace the part.
Repair the harness or
replace the part.
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CRUISE CONTROL SYSTEM - Troubleshooting13-167
I I5Inspection of vacuum pump assemblv drive circuitIIII
id
CRUISE CONTROL
MAIN SWITCH
l-
4-'a
1.1-111.PUMP
@
!52613
12
KK33-AK-R1905
DESCRIPTION OF OPERATIONThe vacuum pump assembly consists of a di-
aphragm type negative pressure pump that is driven
by a DC motor, and two solenoid valves (control
valve and relief valve) and is controlled by the.
control unit as shown in the following table.
When the brake pedal is depressed during cruise
control operation, the power supply to the vacuum
pump assembly is cut off.
TROUBLESHOOTING HINTSDiagnosis No. 11 (Automatically canceled)
ECU terminal voltage
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13-168CRUISE CONTROL SYSTEM - Troubleshooting,I
I 6 IInspection of stop light switch circuitIIIII
FUSIBLE LINK@
IDESCRIPTION OF OPERATIONIJ iWhen the brake pedal is depressed during vehicle
speed control, the cruise control (NC) contact of the
stop light switch is opened to interrupt the power
supply to the vacuum pump assembly for
cancella-tion of vehicle speed control. (Refer to P. 13-I 67.) At
the same time, the stop light (NO) contact is closed.
As a result, a cancel signal is input to the control unit
which internally interrupts the vacuum pump
assembly drive circuit.
TROUBLESHOOTING HINTSECU terminal voltage
Terminal
No.Signal nameConditionTerminal
voltage
15Stop light
switchWhen brake pedal
is depressedSystem
voltage
When brake pedal
is not depressed
OVh
”z15d
El 1’STOP
LIGHT
xx35-AX-R1305
7Inspection of clutch switch circuit
CRUISEc!$;ROLDESCRIPTION OF OPERATIONWhen the clutch pedal is depressed during vehicle
speed control, the contact of the clutch switch is
closed. As a result, a cancel signal is input to the
control unit which internally interrupts the power
supply to the vacuum pump assembly drive circuit
for cancellation of vehicle speed control.
TROUBLESHOOTING HINTSECU terminal voltage
II,Terminal
Signal nameConditionTerminal
No.voltage
1Clutch switchWhen clutch pedalOVis depressed
When clutch pedal System ,
is not depressedvoltage
d
KK35-AK-R130TA
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CRUISE CONTROL SYSTEM - Troubleshooting
INPUT CHECK TABLE
odeDisplay patterns (output codes)Input operationCheck results40.(use with voltmeter)
21SET switch ONSET switch circuit normal
n
22RESUME switch.ONRESUME switch normal
23
nn
Stop light switch ON(brake pedal depressed)
Stop light switch circuit normal
24Vehicle speed more than approx.
40 km/h (25 mph)Vehicle speed sensor circuitnormal if code Nos. 24 and 25
are displayed
25Vehicle speed less than approx.
40 km/h (25 mph)
26M/T
Clutch switch ON
-1~ ~~;~~o~~i~~~~;sed’
(SELECT lever placedin “N” position)Clutch switch circuit normal
Inhibitor switch circuit normal
27CANCEL switch ONCANCEL switch circuit normal
TPS output voltage 1.5 V or more
Throttle position sensor circuit
(Accelerator pedal depressed more normal
than half the way)
Idle switch OFF (Accelerator pedalIdle switch circuit normal
depressed)@ Set main switch to OFF.
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13-180CRUISE CONTROL SYSTEM - Service Adjustment Procedures.
4
ET: ON
07FOOl;Control switch
\E: ON
t
07FOOliControl switch
\
SET: ON
07FOOlControl switch
\
07FOOl
CRUISE CONTROL SETTING CHECK(1) Switch ON the main switch.
(2) Drive at the desired speed within the range of approximate-
ly 40
- 145 km/h (25 - 90 mph).
(3) Operate the control switch downward. (SET switch: ON)
(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 CRUISE indicator light (within the combination
meter) illuminates.
NOTEIf the vehicle speed decreases to approximately 15 km/h (9
mph) below the set speed, because of climbing a hill for
example, the cruise control will be cancelled.
SPEED-INCREASE SETTING CHECK(1) Set to the desired speed.
(2) Operate the control switch upward. (RESUME switch: ON)
(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.
NOTEEven 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 SETTING CHECK(1) Set to the desired speed.
(2) Operate the control switch downward. (SET switch: ON)
(3) Check to be sure that deceleration continues while the
switch is held, and that when it is released the constant
speed at the time when it was released becomes the
driving speed.
NOTEWhen the vehicle speed reaches the low limit [approx-
imately 40 km/h (25 mph)] during deceleration, the cruise
control will be cancelled.
CRUISE CONTROL CANCELLATION AND SET SPEED RE-
SUME CHECK(1) Set cruise control.
(2) In the cruising condition of the cruise control mode, check
that when any of the following operations are performed,
the normal drive mode is restored and
,the vehicle coasts
smoothly.@ Move the control switch toward you. (CANCEL switch:@ Depress the brake pedal.@ Depress the clutch pedal.
@ Place the gear selector lever in the N range.

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CRUISE CONTROL SYSTEM - Service Adjustment Procedures13-183
onoo5J16LO285
141014;
TFA0359
16FO13LResistance
3--1Okl2
STOP LIGHT SWITCH/BRAKE SWITCH INSPECTION(1) Disconnect the connector.
(2) Check for continuity between the terminals of the switch.
O-O: Continuity
Brake switchStop light switch
1423
Whenbrakepedal00depressed.
When
brake
pedal00not depressed.CLUTCH SWITCH INSPECTION
(I) Disconnect the connector.
(2) Check that there is continuity between the terminals when
the clutch pedal is depressed, and that there is no
continuity when the pedal is released.
INHIBITOR SWITCH (“N” POSITION) INSPECTION
(1) Disconnect the connector.
(2) Check to be sure that there is continuity between connec-
tor terminals
@and @when the shift lever is moved to the
“N” range.
VEHICLES SPEED SENSOR INSPECTION
Use circuit tester to check circuit repeats off/on between
terminals when speedometer shaft turned several times.

(1) Remove the vehicle’s speed sensor and connect as shown
in the illustration, using a 3
- 10 kQ resistance.
(2) Use a voltmeter to check for voltage at terminals @ and @
when the pulse generator shaft is turning. (One revolution
is four pulses.)
16R0273
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INTAKE AND EXHAUST - Air Intake Plenum 15-13
AIR INTAKE PLENUM
/REMOVAL AND INSTALLATIQNMlWA-B
L/
i
I Post-installation ODeration
Adjustment of Accelerator Cable
(Refer to GROUP 13 - Engine Control.)
Removal steps7-9ft.lbs.
I. Connection air intake hose2. Connection of accelerator cable_*I)3. Throttle body assemblyl *4. Throttle body gasket
5. Connection of brake booster vacuum hose
6. Harness connecters8 60Nm;6Nm05FOO32
43 ft.lbs.13 ft.lbs.
7. Connection of VIC servo motor
8. EGR pipe
9. EGR valve California>
11. EGR temperature sensor
12. Accelerator cable bracket
13. Connection of air intake plenum stay14. Air intake plenum installation bolts
15. Air intake plenum installation nuts
16. Air intake plenum
17. Air intake plenum gasket
Throttle body
SERVICE POINT OF REMOVALM15UBC23. REMOVAL OF THROTTLE BODY ASSEMBLY
Leaving the water hoses and vacuum hoses in their
installed positions, remove from the air intake plenum.
INSPECTIONM15UCAD2
Check the following points; replace the part if a problem is
found.
AIR INTAKE PLENUM
(1) Check air intake plenum for defect or cracks. Replace if
defective or cracked.
(2) Check load (negative pressure) of drain port. Clean if
required.
SERVICE POINT OF INSTALLATIONMl5UDAB2
4. INSTALLATION OF THROTTLE BODY GASKET
Install with the gasket protrusion positioned as shown.
CautionIf installed in an incorrect direction, idling failure or
other problems may occur.
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15-14INTAKE AND EXHAUST - Air Intake Plenum
AIR INTAKE PLENUM MIBUA-C
REMOVAL AND INSTALLATION
(Refer to GROUP 13 - Engine Control.)
/TurbochargerO&gOSFOOOS5Nm
L
18 Nm18
19 Nm13 ft.lbs.
-05FOO31Removal steps
I. Connection.air hose A2. Connection of accelerator cablea*3. Throttle body assemblyl *4. Throttle body gasket
5. Air pipe A
6. Connection of vacuum hose
7. Connection of brake booster vacuum hose
8. Harness connecter
9. Connection of clutch booster vacuum hose
10. EGR temperature sensor California>
11. EGR valve
12. EGR valve gasket
13. EGR pipe installation bolts
14. EGR pipe gasket
15. Connection of air intake plenum stay
16. Air intake plenum installation bolts
17. Air intake plenum installation nuts
18. Air intake plenum
19. Air intake plenum gasket
SERVICE POINT OF REMOVALM15UBAU3. REMOVAL OF THROTTLE BODY ASSEMBLY
Leaving the water hoses and vacuum hoses in their
installed positions, remove from the air intake plenum.
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