check engine MITSUBISHI 3000GT 1993 2.G Workshop Manual

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.
1 TSB Revision

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.
TSB Revision

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.
TSB Revision

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.
TSB Revision

Downloaded from www.Manualslib.com manuals search engine CHASSIS ELECTRICAL - Theft-alarm Svstem
J, c-66fl,
WC’l----i21c-7712-1
A.Ilx
JJT
@j&j Ek!ifkBoR
51
bEYZIF E
ml
“I: ,.,!!IJ,6,
L
p$zsqc-s’
I2 c-58
m3466
[01
ECUr
%,lcH!i iNDERIC-66
1
CHECKING THE CIRCUIT AND INDIVIDUAL PART1. ETACS POWER-SUPPLY AND GROUND CIRCUITS
Description of operationThe battery supplies a stabilized 5 V power supply to the
ECU, via the constant-voltage circuit and terminal 51 (which
is directly connected to the battery).
ECU terminal voltage (Connection condition of the ECU con-
nector).
I
ECU
SignalConditionTerminal
terminal No.
voltage
51ECU power supplyAt all times12v
2. KEY-REMINDER SWITCH INPUT CIRCUIT
Description of operationThe key-reminder switch is switched OFF and HIGH-level
signals are sent to the ECU when the key is inserted into
the ignition key cylinder: when the key is removed, the key-re-
minder switch is switched ON and LOW-level signals are sentto the ECU.
ECU terminal voltage (Connection condition of the ECU con-
nector).
I
ECUTerminal
terminal No.SignalConditionvoltage
\
L)
L)
64Key-reminder
switch
Key removed12 V
Key inserted0 V
d
1 TSB Revision

Downloaded from www.Manualslib.com manuals search engine iCHASSIS ELECTRICAL
- Theft-alarm System54-229
JS!SECURITYE-04@y&fiNAT! ON .$36
152
FUSIBLE LINK CE)m
z0alz!
r%BECATED
mCL
1
TO THE ECUTO THE HORN8. SECURITY LIGHT ACTIVATION CIRCUIT
Description of operation
If all doors are in locked state after key-less locking, the ECUtransistor is turned ON and the security light comes on.
Checking the security light activation circuit (Disconnect the
connector of the ECU and check at the wiring harness side.)Nor-
malMal-
stepCheck objectcondi-func-
Cause
Remedy
tiontion
1D-04connector12v ovterminal voltage 51Fuse (19) dam-Replaceaged or discon-the fusenetted
Harnessdam-Repair the
aged or discon-harnessnetted, or short-circuit
2D-04connector12v ovterminal voltage 52Damaged or dis-
Replaceconnected wiringthe bulbofSECURITYlight bulb
Harness
dam-Repair the
aged or discon-harnessnetted
3ECU terminal volt-12v ovHarnessdam-
age 57Repair the
aged or discon-harnessnetted, or short-circuit9. HORN RELAY POWER-SUPPLY CIRCUIT
Description of operationPower voltage is always supplied to the horn relay.
Checking the horn relay power-supply circuit (Disconnect the
horn relay)
connector terminal
Mal-func-CauseRemedytion
Fuse (3)
dam-Replace the
aged or discon-fusenetted
Damaged or dis-Repair the har-connected har-nessness
TSB Revision

Downloaded from www.Manualslib.com manuals search engine .,i”i, LlNl Q10. HORN ACTIVATION CIRCUIT
?a/ ;
dl
spored10.
Description of operation
The ECU transistor is turned ON if the vehicle door, etc. are
opened without use of the key.
This energizes the horn relay to activate the horn.
Checking the horn activation circuit (Disconnect the connector
of the ECU, then short-circuit terminal connector No.58, and
activate the horn relay.)
54-230CHASSIS ELECTRICAL - Theft-alarm System
z “2
EL? II A-as ’
I3 Ii3
c!
ig”‘“,1 u~cw ~ I A.,Op+J
x
6IZ)Y.l,.-”Step
1Check objectmatMal-
I Icondi- functionCauseRemedy
Horn relay termi-nalvoltage(4-Ground)12v ovMalfunction of
Check thethe horn relayhorn relay
(Refer to
P.54-118.)
Horn terminal volt-12v ovHarnessdam-age (LH & RH)Repair the
aged or discon-harness(1 -Ground)netted
Horn terminal volt-age (LH & RH)(1 -Ground)Nor-
1IItion
HornHornMalfunction ofReplacesoundoesn’tthe hornthe hornds (0 sound
V)(0 w
BatteryDamaged or dis-Repair thevoltageconnected wiringharness
of ground circuit
11. THEFT ALARM HORN RELAY POWER-SUPPLY
CIRCUIT
Description of operation
Power voltage is always supplied to theft alarm horn relay.
Checking the horn relay power-supply circuit (Disconnect the
theft alarm horn relay)Check object
THEFT ALARMHORNRELAYconnector terminal
voltage 1NormalMal-
condi-func-
CauseRemedy
tion
tion
12v
ovFuse (14)
dam-Replace the
aged or discon-fusenetted
Damaged or dis-Repair the har-connected har-nessness
TSB Revision

Downloaded from www.Manualslib.com manuals search engine i
LCHASSIS ELECTRICAL
- Theft-alarm System54-231
Fwbklink (6)A-26
8=’ Theft-
alarm
ECUA 27
i
1 *horn
al
Z16FO342
TO Ecu
auO-U-RS4I2-YI
12. THEFT ALARM HORN ACTIVATION ClRCUlT
Description of operation
The ECU transistor is turned ON if the vehicle door, etc. are
opened without use of the key.
This energizes the theft alarm horn relay to activate the horn.
Checking the horn activation circuit (Disconnect the connector
of the ECU, then short-circuit terminal connector No. 58, and
activate the theft alarm horn relay.)
13. HEADLIGHT POWER-SUPPLY CIRCUIT
Description of operation
Power voltage is always supplied to the headlight relay.
Checking the headlight power-supply circuit (Disconnect the
headlight relay)
Check objectNormalMal-condi-func-CausetiontionRemedy
(Wiring
harness12 vovside) terminal volt-Fusible link (3)Replace theblownfusible link
age (5-Ground)Damaged or dis-Repair the har-connected har-nessness
1 TSB Revision

Downloaded from www.Manualslib.com manuals search engine 54-232CHASSIS ELECTRICAL - Theft-alarm System
14. HEADLIGHT ACTIVATION CIRCUIT

k&w; s’._____.om-
R
43-? -R5
Ic-m 3
*
JOtaC-82 5w
ii
Description of operationThe ECU transistor is turned ON if the vehicles
door, etc. are opened without use of the key. This
energizes the headlight relay to active the headlight.Checking the headlight activation circuit (Disconnect
the connector of the ECU, then short-circuit terminalconnector 2, and activate the headlight relay.)
TSB Revision

Downloaded from www.Manualslib.com manuals search engine CHASSIS ELECTRICAL - Theft-alarm Svstem54-233
1
2
3
cFronSW
1,
id
2
3
n
i
I1993
models>
Check object
NormalMal-
condi-function
tionHeadlight relay terminal voltage
(4-Ground)12v
OV
Headlightterminal12vOV
(3-Ground)voltageHeadlight
termi- Column switch: OV
nalvoltage Low
(1 -Ground)Column switch:12vHiHeadlight
termi- Column switch:12v
nalvoltage Low
(2-Ground)Column switch: OV
Hi
The
head-
light
isn’t
turned
on.1994
models>
Check object
NormalMal-
condi-function
tionHeadlight relay terminal voltage
(CGround)12vov
Headlightterminal
voltage12vov
(2-Ground)Headlight (HI)
terminal voltage
(1 -Ground)Headlight (LO)
terminal voltage
(2-Ground)
-r
/
Column switch:12v
LowColumn switch: OV
HiColumn switch: OV
LowThe
head-
light
isn’t
turned
on.Column switch: OV
HiCauseMalfunction of the
headlight relay
Harness damaged or
disconnectedMalfunction of the
headlight.
Harnessdamaged or discon-
nected. Malfunction of
column switch.
CauseRemedyMalfunction of the
headlight relay
Harness damaged or
disconnectedMalfunction of the
headlight.
Harnessdamaged or discon-
nected. Malfunction of
column switch.RemedyCheck the headlight
relay(Refer to
P.54-108.)
Repair the harness
Replace the headlight
orcolumnswitch.
Repair the harness.Check the headlight
relay(Refer to
P.54-108.)
Repair the harness
Replace the headlight
orcolumnswitch.
Repair the harness.
TSB Revision