1991 MITSUBISHI 3000GT sensor

CRUISE CONTROL SYSTEM - Troubleshooting13-169
8Inspection of inhibitor switch circuit
LDESCRIPTION OF OPERATIONThe inhibitor switch is interlocked with the starter
switch. When the gear selector lever is placed in the
“N” position during vehicle speed control, 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
>
%
‘18@
INHIBITOR
SWITCHspeed.TROUBLESHOOTING HINTSECU terminal voltage
Terminal
Signal nameConditionTerminal
No.voltage
1Inhibitor switchInhibitor switch inov
“N” or “P” position
System
voltage
STARTER=
L;RX%-AK-R1907
9Inspection of throttle position sensor circuit
ENGINE
CONTROL
UNIT
:l:DOHC
*-OFF 01
w2,3' /% *
THROTTLE;;f&;iON
{ml@
CRUISE CONTROL UNITKX.95~AC-R1308
DESCRIPTION OF OPERATIONThe throttle position sensor (with built-in idle switch)
is used for engine control as well as cruise control.
The throttle position sensor sends data to the
control unit, regarding the opening of the accelera-
tor. The idle switch inputs the data to the control
unit on whether or not the accelerator pedal is
operated.
TROUBLESHOOTING HINTSDiagnosis No. 17 (Not automatically canceled)
ECU terminal voltage
Signal nameConditionTerminal
voltageIdle switchWhen accelerator OV
pedal is depressed
When accelerator 4.5
- 5.5V
pedal is not de-
pressed
Throttle position During idle0.48
-sensor0.72V
When fully opened 4.0
- 5.5V
TSB Revision

13-170CRUISE CONTROL SYSTEM - Troubleshooting
10Inspection of circuit associated with accelerator pedal switch OFF function
IGNITlOiiI sw1:
Ind
,277
?IOA-..A-"2Y
.
“3EL
3,"I\-
2
.-----------
E
r
r
g:-1
13--
ii
KH(IG2)
ORi13 : DI
"CLt-t-fi[T
UNIT
DESCRIPTION OF OPERATION‘\JThe accelerator pedal switch is used to detect the
operating state of the accelerator pedal. It is one of
the sensors of the
ELC4A/T automatic transmis-
sion. Since the accelerator pedal is not operated
during vehicle speed control,.the cruise control unit
forces transistor
Tr, into the OFF state, creating the
same state as when the accelerator pedal switch is
placed in the OFF state.
1
$iK&ERATOR
SWITCHH
1
2
-I
CRUISE
CONTROL
UNIT
TROUBLESHOOTING HINTSECU terminal voltage
TerminalNo.Signal name
Condition
3Accelerator pedal switch control
power supplyWhen ignition switch is placed at ON
9Accelerator pedal switchWhen accelerator pedal is depressed
When accelerator pedal is not depressed
System voltage
TSB Revision

CRUISE CONTROL SYSTEM - Troubleshooting
DIAGNOSIS DISPLAY PATTERNS AND CODES
13473
CodeDisplay patterns (output codes)Probable causeCheck chart No.No.(Use with voltmeter)
11l-l n-JILL
The same pattern repeatedly displayed
Vacuum pump assembly drive output systemout of order5
I I12Vehicle speed signal system out of orderI4I
I In
Control switch out of order (When SET or2RESUME switch is kept in ON statecontinuously for more than 60 seconds)
Control switch out of order
Throttle position sensor or idle switch out9
of order
Normal code
12AOlOa
NOTE
1. When two or more problems occur simultaneously, the
three latest code numbers are displayed in the order of
lowest code number first.
2. Even if the problem represented by the code number
marked * occurs during cruise control operation, the cruise
control mode will not be canceled.
3.When the system is normal, the diagnosis code is displayed
as described below.@ If a multi-use tester is used:
“NORMAL!
! I’ will be displayed.@ If a voltmeter is used:
Continuous ON/OFF signals will be displayed at 0.5
second intervals. (Refer to the illustration at the left.)
INPUT CHECKINGInput checks should be made when the cruise control system
cannot be set and when it is necessary to check (when a
malfunction related to the cruise control system occurs)
whether or not the input signals are normal.
NOTE
1.If inspection of self-diagnosis is necessary, confirm diagno-
sis code first and conduct input check.
2. Input check can be conducted by set operations.
Self-diagnosis terminal outputs display patterns.
3. Display codes are displayed only if the circuit is normal
according to the conditions shown in the table on the next
paw.Perform checks using the following procedures.
(1) Connect a multi-use tester or a voltmeter to the diagnosis
inspection connector of the junction block.
NOTEConnect a voltmeter using the same procedure as for
inspection of diagnosis output.
TSB Revision

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.
1 TSB RevisionI

13-176CRUISE CONTROL SYSTEM - Troubleshooting
HARNESS AND COMPONENTS LAYOUT
ENGINE COMPARTMENT
01 Jumper connector
02 Vacuum pump
03 Throttle position sensor04 Inhibitor switch
05
VeTkFo;peed sensor
INSTRUMENT PANEL
AND FLOOR CONSOLE
Combination meter
Main switchEngine front view
03
36FOOO5Engine rear view
16FO175
36FOO17
TSB Revision

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
TSB Revision

13-184CRUISE CONTROL SYSTEM - Service Adjustment Procedures
07AOO51
07A005t07A005i
THROlTLE POSITION SENSOR INSPECTIONFor inspection, refer to
P.13-65.
IDLE POSITION SWITCH INSPECTIONFor inspection, refer to
P.13-68.VACUUM PUMP INSPECTION
Inspection of Solenoid Valves (Control and Relief Valves)(1) Disconnect the connector of the vacuum pump assembly.
(2) Measure the resistance values across terminals @ and @
and across terminals @ and
0.Standard value: 50
- 60 R
(3) Check that when the battery voltage is applied across
terminals @ and @ and across terminals @ and
0, the
operating sounds of the solenoid valves are heard.
(4) If the solenoid valves are defective, replace the vacuum
pump assembly.
Inspection of Motor
(1) Disconnect the connector of the vacuum pump assembly.
(2) Check that when the battery voltage is applied across
terminals @ and
@, the motor operates.
ACTUATOR INSPECTION(1) Remove the actuator.
(2) Using a vacuum pump, apply a negative pressure to the
actuator to check that the holder portion moves more than
35 mm (1.4 in.). Retain the negative pressure in that state to
check that the holder portion does not change its position.
(3) After the actuator has been mounted, check and adjust the
cruise control cable. (Refer to
P.13-178.)
TSB Revision

13486CRUISE CONTROL SYSTEM - Cruise Control System
1.6
- 2.2 ft.lbs.
07FOO27
Removal steps of control switches
l *20. Air bag module
21. Air bag module bracket
22. Cruise control switch
23. Switch garnish24. Main switch
Removal steps of sensors and switches
28. Throttle position sensor
29. Accelerator pedal switch30. Stop light switch
31. Clutch switch
32. Vehicle speed sensor (Refer to GROUP 54 - Meters and Gauges.)33. Vehicle speed sensor (Refer to GROUP 54 - Meters and Gauges.)
4*
4*
Removal steps of control unit
25. Scuff plate (R.H.)26. Cowl side trim (R.H.)27. Cruise control unit34. Inhibitor switch

2807FOO28
68FOO12
07FOO20
TSB Revision