1993 MITSUBISHI 3000GT check engine

Downloaded from www.Manualslib.com manuals search engine 54-202CHASSIS ELECTRICAL - Rear Window Defogger
With voltmeterData link connector
When using the MUT-IICUD to 1993 models>
Y2OFO16400002231
Ground
INPUT SIGNAL

When using the scan tool
(MUT) or voltmeter
Using the scan tool or voltmeter, check whether or not the
input signals from each switch are being input to the ETACS
unit.
(1) Connect the scan tool to the data link connector located
at the right side of the junction block or connect the voltme-
ter between the ETACS terminal and the ground terminal.
(2) Check if the buzzer of the scan tool sounds or the needle
of the voltmeter moves when each switch is operated.
If the buzzer sounds or the needle moves, the input signalsare being input to the ETACS unit, so that switch can
be considered to be functioning normally. If not, the switch
or switch input circuit is faulty. Check the switch and the
switch input circuit.

When using the scan tool (MUT-II)
(1) Connect the scan tool to the data link connector. When
connecting the scan tool to a vehicle up to 1993 models,
use the adapter harness supplied together.
Caution
Turn off the ignition switch beforehand whenever thescan tool is connected or disconnected.
(2) If the scan tool makes a peep sound when each switchis operated (turned ON/OFF), the input signal to ECU
is normally sent from the switch circuit system. 1994 models>
When using the voltmeter
(1)Connect a voltmeter to the ETACS terminal and the ground
terminal of the data link connector using the special tool.
(2) If the voltmeter pointer deflects once when each switchis operated (turned ON/OFF), the input signal to
.ECU
is normally sent from the switch circuit system.
U2OFO163
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Downloaded from www.Manualslib.com manuals search engine CHASSIS ELECTRICAL - Rear Window Defogger54-203
L
L-J
c
Normal characteristic curve
Voltage
j\
PositivePrinted heater lineterminalNegativeterminal
Abnormal characteristic curve
Voltage
Qj (( r”!“Yui;
Positive
terminalPrinted heater line Negativeterminal
216Y332
BreakTape
\
Conductive
paint
216Y333
16FO16700002409ON-VEHICLE SERVICE
THE PRINTED-HEATER LINES CHECK
(1) Run engine at 2,000 rpm. Check heater element with bat-tery at full.
(2) Turn ON rear window defogger switch. Measure heater
element voltage with circuit tester at rear window glass
center A.
Condition good if indicating about 6 V.
(3) If 12 V is indicated at A, there is a break in the negative
terminals from A.
Move test bar slowly to negative terminal to detect where
voltage changes suddenly (0 V).(4) If 0 V is indicated at A, there is a break in the positive
terminals from A. Detect where the voltage changes sud-
denly (12 V) with the same method described.
THE PRINTED-HEATER LINES REPAIR
REQUIRED MATERIALSl Thinner
l Tapel Lead-free gasoline
l Fine brush
l Conductive paint
(1) Clean disconnected area with lead-free gasoline. Tape
along both sides of heater element.
(2) Mix conductive paint thoroughly. Thin the required amount
of paint in a separate container with a small amount of
thinner and paint break three times at 15 minute intervals.(3) Remove tape and leave for a while before use (circuit
complete).
(4) When completely dry (after 24 hours) finish exterior with
a knife.
Caution
Clean glass with a soft cloth (dry or damp) along defog-
ger heater element.REAR WINDOW DEFOGGER SWITCH
(1)Remove rear window defogger switch from the meter bezel.(Refer to
P.54-109.)
(2) Operate the switch and check the continuity between the
terminals.
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Downloaded from www.Manualslib.com manuals search engine INSPECTION

I I IIQ!-hh&Connect battery power source to terminal 5. Check circuitbetween terminals with terminal 3 grounded.
lBFO206cl994 models>00002410
54-204CHASSIS ELECTRICAL - Rear Window Defogger
~1
~1994 models>Connect battery power source to terminal 1. Check circuit
between terminals with terminal 3 grounded.
L---i00002411
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Downloaded from www.Manualslib.com manuals search engine CHASSIS ELECTRICAL - Theft-alarm Svstem54-205
THEFT-ALARM SYSTEM
L,
SPECIAL TOOLS
L
Q
Tool number and name
MB991 341
Scan tool
(Multi-use tester
)
ROM Pack
(For the number,refer to GROUP 00
-
Precautions Before
Service.)
MB991 502
Scan tool
(MUT-II)
ROM pack
MB991
52%.
Diagnostictrouble
code check harnessSupersession
MB991 341 C
MB991 502
MB991 529
i
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Application
Up to 1993 models
Checking the theft-alarm system
All models
Checking the theft-alarm system
From 1994 models
Checking the theft-alarm system
using a voltmeter

Downloaded from www.Manualslib.com manuals search engine 54-220CHASSIS ELECTRICAL - Theft-alarm Svstem
With voltmeterData link connector
\‘%S$F- Data link t Ground ETACS z16R1338
When using the MUT-II4Jp to 1993 models>
Y2OFO16400002231TROUBLESHOOTING GUIDE
CHECKING THE INPUT
When using the scan tool
(MUT) or voltmeter
1. Connect a voltmeter between terminal for ETACS and
terminal for ground, or connect the scan tool to the data
link connector.
‘d

When using the scan tool (MUT-II)
1.Connect the scan tool to the data link connector. When
connecting the scan tool to a vehicle up to 1993 models,
use the adapter harness supplied together.
Caution
Turn off the ignition switch beforehand whenever thescan tool is connected or disconnected.vi
UZOFOlfX3

When using the voltmeter
1.Connect a voltmeter to the ETACS terminal and the ground
terminal of the data link connector using the special tool.
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Downloaded from www.Manualslib.com manuals search engine iCHASSIS ELECTRICAL
- Theft-alarm Svstem54-221
(Output)Voltmeter rvv 1-1
Scan tool(Buzzer %,isound)16FO5712. Make sure that when the following switches are turned
on, the output shown in the illustration is delivered. (Only
those switches which are related to the theft-alarm system
are listed here.)
0Driver and front passenger door switchesl Headlight switch
lDriver and front passenger door lock switchesl Passing light switch
l Pop-up switch (up to 1993 models)
l Hood switch
l
Liftgate switch
l Door key cylinder switch
l
Liftgate switch
If there is no output of a voltage pattern at all, check
for a malfunction of that switch or for damaged or discon-
nected wiring.
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Downloaded from www.Manualslib.com manuals search engine 54-222CHASSIS ELECTRICAL - Theft-alarm System
TROUBLESHOOTING QUICK-REFERENCE TABLE
For information concerning the locations of electrical components, refer to GENERAL-Theft-alarm System
Circuit.
1.ARMING / DISARMING RELATIONSHIP
Trouble symptomThe system is not armed (The
SECURITY light doesn’t illumi-
nate, and the alarm doesn’t func-
tion.)
(The central door locking system
functions normally.
If the central locking system doesnot function normally, refer to
GROUP 42.)
The arming procedures are fol-
lowed, but the SECURITY light
does not illuminate.(There is an alarm, however,
when an alarm test is conductedafter about 20 seconds have
passed.)
The alarm sounds in error when,
while the system is armed, a door
or the liftgate is unlocked by us-
ing the key.
ICause
Damaged or disconnected
wiring of ECU power sup-
ply circuit
Damaged or disconnected
wiring of door switch input
circuit
Damaged or disconnectedwiring of SECURITY light
activation circuit.Blown SECURITY light
bulb
Malfunction of the ECU.
Damaged or disconnected
wiring of a door key cylin-
der and the
liftgate unlock
switch input circuit.
Malfunction of a door key
cylinder and the liftgate un-
lock switch.
Malfunction of the ECU.
2.ACTIVATION / DEACTIVATION RELATIONSHIP
Trouble symptomCauseThere is no alarm when, as an
Damaged or disconnected
alarm test, a door is opened with-wiring of door switch (all
out using the key.doors) input circuit
(The arming and disarming arenormal, and the alarm is
acti-Malfunction of the door
vated when the liftgate or hood isswitch
opened.)
Malfunction of the ECUThere is no alarm when, as an
Damaged or disconnected
alarm test, the liftgate is opened
without using the key.wiring of liftgate switch in-
put circuit
(The alarm is activated, however,
by opening a door or the hood.)Malfunction of the liftgate
switch.
Malfunction of the ECU.Check methodCheck by using check
chart P.54-224.Check by using check
chart P.54-225.Check by using check
chart P.54-229.
If input checks
(P.54-220) indicate amalfunction, check by
using check chart
P&f-227.
Check method
If input checks
(P.54-220) indicate a
malfunction, check by
using check chart
P.54-225.
If input checks
(P.54-220) indicate a
malfunction, check by
using check chart
P.54-228.
Remedy
Replace the fusible link
No. (6) or the fuse No.
(19).Repair the harness.
Repair the harness or re-
place the door switch.
Replace the fusible linkNo. (6) or the fuse No.(1%
Repair the harness.
Replace the bulb.
Replace the ECU.
Repair the harness or re-
place a door key cylinderand the
liftgate unlock
switch.
Replace the ECU.
Remedy
Repairthe harness or re-
place the door switch.
Replace the ECU.
Repair the harness or re-
place the liftgate switch.
Replace the ECU.
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Downloaded from www.Manualslib.com manuals search engine CHASSIS ELECTRICAL - Theft-alarm System54-223
Trouble symptom
Cause
Check method
Remedy
There is no alarm when, as analarm test, the hood is openedDamaged or disconnected
wiring of hood switch input
If input checks
Repairthe harness or re-
from within the vehicle.circuit.
(P.54-220) indicate aplace the hood switch.
(The alarm is activated, however,malfunction, check by
I
by opening a door or the liftgate.)using check chartMalfunction of the hood p.54-225.
switch.
Malfunction of the ECU.
-Replace the ECU.
Engine would not start [EngineThere is a short-circuit of
starting is possible when the the starter relay activationCheck by using check
chart P.54-234.
Repair the harness.
starter relay is in the switched-off
circuit
(normally closed) condition, with
the clutch switch in the switch-off
and the ECU harness connector
disconnected.]
When, as a test of the alarm, aDamaged or disconnectedCheck by using check
door or the
liftgate is opened wiring of headlight power chart P.54-231, 232.
Repairthe harness or re-
without using the key, orthe hood
is opened from within the vehicle,supply circuit or headlightplace the diode Ds.
activation circuitReplace the headlight
the horn and the theft-alarm hornrelay or the headlight.sound but the headlights don’t
flash. (The headlights can, how-
ever, be switched. ON by usingMa
lfunction of the ECUReplace the ECU.
the passing switch.)The headlights flash during an
alarm test but the horn orthe theftDamaged or disconnectedCheck by using checkRepair the harness.
alarm horn does not sound.wiring of horn relay power
chart P.54-229,230,231.supply circuit or horn ac-Replace the horn.
tivation circuitReplace dedicated fuse
Damaged or disconnectedNo. (6) or the fusible linkwiring of the theft-alarmNo. (6).horn relay power supply
circuit or the theft-alarm
horn activation circuit.
Malfunction of the ECU.
Replace the ECU.The system is not deactivated
nhen, during an alarm test in
Damaged or disconnected
If input checks
which the alarm is intentionallywiring of door key cylinder
Repair the harness.activated, the door or
liftgate isand
liftgate unlock switch(P.54-220) indicate a
input circuitmalfunction, check byReplace the key cylinder
Jnlocked by using the key.
using check chartswitch or the
liftgate
switch.
:The system also cannot be dis-P.54-227,228.
armed.)
Malfunction of door keycyl-inder and liftgate unlock
switch.
Malfunction of the ECU
Replace the ECU.
ECU: Electronic Control Unit
NOTEIf the
lifigate unlock switch or door key cylinder unlock switch is operated roughly, or if these switches have
been installed incorrectly or switches themselves are defective the ECU may not accept the warning or alarmcancelling signal. In such case, the alarm operation will take place when the door is opened using a key.
[When the door key cylinder switch has been shorted, however, if the ignition switch is turned ON, the ECU
judges the detection-switch as faulty and thereafter, it will prevent setting of (warning) alarm until the shorting
is corrected.]
If the
liftgate is opened using a key and is left opened when the door key cylinder switch system has a trouble
(wiring harness damage, open circuit, etc.), the ECU judges it as the
liftgate holding mode and does not producealarm even when the door is opened.
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